[Group] YAMAHA RXZ

[Thanh-BKK]

Hi.

 

If the bike smokes real bad it is possible that the shaft seal on the right side of the crank shaft is damaged and the engine sucks in/burns engine oil. This will generate a lot of white/grey-ish smoke and also a rather typical smell.

 

Changing that seal in an RXZ engine requires the engine to be taken out and the right side of the engine to be dismantled, it is quite a lot of work incolved. I guess the mechanic quoted that repair.

 

If that is the case, parts needed:

 

Shaft seal

Engine case gasket

Block foot gasket

Block head gasket

Outlet gasket

Engine oil

 

And about one hour of work time for the mechanic if he's a good mechanic.

 

if this work really has to be done i recommend changing the bearings all at once, too - after all the engine is already out and apart.

 

However another possibility is "too high 2T intake" - in that case the 2T will be used up quite quickly. This can be set from outside with the adjuster screws on the cable that goes to the 2T pump. HOWEVER for that to generate a lot of smoke the intake must be REALLY high - i have mine set quite high (one Liter of 2T = ~800 kilometers) and there is not much smoke except when i really whack it, and even then it is nowhere "like a smoke grenade".

 

A third possibility is a lot of carbon buildup in the pipe, or rather oil deposit in there. In that case it will only start to smoke when the pipe becomes hot, i.e. not during the first kilometer or so. If this is the case you will also notice black goo coming out of the end of the pipe, and quite a lot of it. Check your pipe - in the lowest part there should be one screw (10mm head) that can be removed. Remove it and use a small (5mm diameter) philips (cross head) screwdriver to stick into the hole to open it (maybe carbon blocking it from inside), then run the engine for some time to make sure the pipe gets really hot and the oil inside really liquid. The oil will come out of that hole which is there for this exact purpose.

 

Best regards.....

 

Thanh

[syamitomo]

Hi.

 

If the bike smokes real bad it is possible that the shaft seal on the right side of the crank shaft is damaged and the engine sucks in/burns engine oil. This will generate a lot of white/grey-ish smoke and also a rather typical smell.

 

Changing that seal in an RXZ engine requires the engine to be taken out and the right side of the engine to be dismantled, it is quite a lot of work incolved. I guess the mechanic quoted that repair.

 

If that is the case, parts needed:

 

Shaft seal

Engine case gasket

Block foot gasket

Block head gasket

Outlet gasket

Engine oil

 

And about one hour of work time for the mechanic if he's a good mechanic.

 

if this work really has to be done i recommend changing the bearings all at once, too - after all the engine is already out and apart.

 

However another possibility is "too high 2T intake" - in that case the 2T will be used up quite quickly. This can be set from outside with the adjuster screws on the cable that goes to the 2T pump. HOWEVER for that to generate a lot of smoke the intake must be REALLY high - i have mine set quite high (one Liter of 2T = ~800 kilometers) and there is not much smoke except when i really whack it, and even then it is nowhere "like a smoke grenade".

 

A third possibility is a lot of carbon buildup in the pipe, or rather oil deposit in there. In that case it will only start to smoke when the pipe becomes hot, i.e. not during the first kilometer or so. If this is the case you will also notice black goo coming out of the end of the pipe, and quite a lot of it. Check your pipe - in the lowest part there should be one screw (10mm head) that can be removed. Remove it and use a small (5mm diameter) philips (cross head) screwdriver to stick into the hole to open it (maybe carbon blocking it from inside), then run the engine for some time to make sure the pipe gets really hot and the oil inside really liquid. The oil will come out of that hole which is there for this exact purpose.

 

Best regards.....

 

Thanh

 

Spoken like a true RXZ expert. There u go SantaCros...

[SantaCros]

Thanh what you said sounds like sense. My rxz every week topup 2t and 4t. Cuz the 4t kena eaten by the engine. No wonder so much smoke. Also i open the 2t pump pull off the 2t pipe and bike still smoking. Maybe the oil seal is really burst must change but is it really 2 to 3 hundred just to change? My piston never jam. I also open the exhaust the muffler before, whole thing cover in thick goo made from oil.

[Thanh-BKK]

Hi

 

Yes, if your engine oil ("4T") is disappearing without it dropping from the engine (no oil stains under the bike) then this is the cause - your engine burns it, you must replace that oil seal.

 

I can not quote a price or comment on it because i am not in Singapore, in fact i live in Bangkok/Thailand and don't know how much such repairs cost in Singapore..... however as i described above, it is quite some work to change that particular seal so yes, it may be expensive.

 

If you are at it, as i mentioned, have them change all bearings and remaining seals, too, those seals and bearings can be bought in a complete set for one engine which cost less than buying them all separately. Bearings will sooner or later fail and when you need to take the engine out and take it apart anyway it does not hurt to do it all in one "go", your engine will feel much better after that.... believe me, i have done it with mine before.

 

As long as your engine burns 4T the piston will not jam, 4T does the same job as 2T in lubricating the piston..... however 4T is not designed to burn, it burns very unclean and hence you will have the black goo in your pipe. This will decrease the power of your engine.

 

Also, very important - through the damaged seal the engine can (and sooner or later will) also suck in air - which will lean out the engine and THAT can cause a piston jam.

 

Also clean your pipe when you do the engine repair - as long as it is still liquid goo inside it is easy to clean, close the pipe on one end (preferably at the header) and fill the entire pipe with a strong solvent (can use petrol or, if available, Bio-Diesel... otherwise some other stuff that solves oil) and keep it standing for a day or two. Alternative you can burn it out but after that you will need to re-paint the pipe or it will rust (burning out a pipe destroys the paint on it). Do NOT burn out a catalyzer pipe!! This will destroy the catalyzer.

 

Best regards.....

 

Thanh

[Izammo]

This can be set from outside with the adjuster screws on the cable that goes to the 2T pump.

 

hi Thanh and everyone, where exactly is this screw adjuster?

 

and for spark plug cap, how much does it cost normally? mine went kaput and changed for $10, including new spark plug, it's okay right?

 

the new plug cap is like this.

http://cometmotorsports.com/store/spark/images/ngkcap.jpg

[Thanh-BKK]

Hi

 

The 2T adjuster is located between the end of the cable and the curved metal tube that leads to the 2T pump on the right side of the engine. Look at that curved metal tube (quite short), at it's end the black cable comes out that goes under the tank. Between the two is a hollow "screw" that is used to adjust the 2T intake - turn this screw just like you would turn a normal screw (8 or 9mm wrench required), if you screw it out of the curved tube you INcrease the 2T, if you screw it in you DEcrease the 2T. There is also a nut (10mm wrench required) to secure the adjuster screw after it is set.

 

The whole adjuster might be hidden under a rubber cap for protection against rain water.

 

The spark plug cap is a good one, i have been trying to find these in Thailand for well over two years and found it to be impossible - only fakes ("NCK") available, i finally got a genuine NGK via E-Bay Again i can't judge the rpice in Singapore, mine cost (per piece) 2.49 US$ and a spark plug (genuine NGK!) here in Bangkok cost around 35 Baht, roughly 1 US$.

 

Kind regards.....

 

Thanh

[SantaCros]

Thanks Thanh, you have a good deal of knowledge regarding motorcycles. Thats very good to have in daily life. Do you do your own maintanaince on your bikes? Indeed rxz is a bike with personality, the two stroke sound and look of the bike is unique, unlike big cc's bike. They are just big bike with power and speed, but tiring to ride for long everyday. Hope u come to singapore one day and if u do, try not to visit our local motorcycle shops. They are sharks who eat your pocket.

[syamitomo]

Thanks Thanh, you have a good deal of knowledge regarding motorcycles. Thats very good to have in daily life. Do you do your own maintanaince on your bikes? Indeed rxz is a bike with personality, the two stroke sound and look of the bike is unique, unlike big cc's bike. They are just big bike with power and speed, but tiring to ride for long everyday. Hope u come to singapore one day and if u do, try not to visit our local motorcycle shops. They are sharks who eat your pocket.

 

Got to agree wif tat!

[Thanh-BKK]

Hi

 

Thanks for that. I guess for me it must come sort of naturally - fixing motorbikes (and specially two-strokes) used to be my trade in my home country (Germany), after all i am a certified mechanic

 

I love my RXZ because it is absolutely reliable, in over three years and 54,000+ kilometers it did not let me down even once. Granted, small issues here and there but i always got home. I love to work on the bike because it is relatively easy to fix and modify, made difficult in Thailand only because of the lack of available parts - RXZ used to be made here (both mine are Thai made) however both making and selling them stopped in 1996, hence the "newest" RXZ in Thailand are those from 1996...... and, like with all bikes here, as soon as it is no longer available the spare parts start to disappear. VERY difficult to find genuine Yamaha spares from old stock, and most after-market parts are of really poor quality.....

 

Further problems arise from a lack of quality tools - the stuff one can buy at places like "Home Pro" is rarely fit for the job, i had wrenches break upon first usage.... this is the reason why i do most of the "deeper" modifications and/or repairs at a bike shop where the owner, a Chinese gentleman, allows me to do my own work with their tools, as long as i buy my parts there. Some works, like building wheels or changing bearings etc, i let them do because it would take me too long..... after all i have a full-time job and only a few hours every morning available (i work 11 am to 8:30 pm).

 

I have been riding two-stroke bikes since i was 16 years old, mostly mopeds (50cc) of the "Zundapp" brand, in Germany..... back then they were "old junk" but by now they are very expensive classics (that company closed it's doors in 1984). I used to be the proud owner of Zundapp's largest modern bike, the KS 175, which i sold for spare parts in early 2000 after it failed it's road-worthiness test due to rust..... i did not have the time or the money for a restoration then. Today i would get about 25x the money for the engine alone......

 

The only four-stroke bike i ever personally owned was a Honda CB 250 and after it seized up on me i swore "no four-stroke again, ever". So, naturally, after having finally convinced my boyfriend here in Thailand that i need a motorbike it had to be a two-stroke and it became an RXZ because this RXZ came to me as a real challenge - a poor heap of scrap metal basically, but cheap and with a working engine (it was about the only thing that worked). That same RXZ is still with me, it is the black one i call "Bulldozer". Later it got a brother, my second RXZ - the red one, named "Destiny". There used to be a previous second one which i bought only to scrap it as the black one's frame was broken and i needed a frame, impossible to buy in Thailand so a whole bike it had to be, luckily it came with some nice parts attached (the bored-up and ported block that i still run among them) .

 

Sadly my financial situation isn't all that good, i have big plans for the red one... i want it to become a real racing bike, however the required modifications cost a lot of money which never seems to become available to me.... and also i am planning to have a third RXZ one day, that one i want to make into a scrambler type of bike (off-road). RXZ are very versatile due to their engine - that engine has a lot of torque while at the same time also able to rev high and generate a lot of horse power, specially with a little porting.... and because it lacks such "high tech" features like YPVS or similar it is very easy to work on.

 

I understand that in Singapore RXZ seems to be some sort of beginner's bike because you have different classes of license - in Germany they have, too, however i hold the unrestricted license from Germany and here in Thailand is only one class anyway - but i am not looking for a bigger bike, for one they are crazily expensive here and then - RXZ is about the "largest" bike that still has the advantage of snake-ing through the notorious traffic jams, with a Honda CB 400 for example i would be helplessly stuck and could as well drive the truck.

 

That, and said Honda is a four-stroke again - which i don't want.

 

Kind regards......

 

Thanh

[Thanh-BKK]

Oh, forgot....

 

Yes, one of my dreams is to one day ride Singaporean roads with my trusty Bulldozer After all there are a whole bunch of parts in it that originate in Singapore, thanks to friends from this forum..... and i guess that your local police would go bonkers upon seeing that bike, as i know that many of the modifications on it are strictly illegal in Singapore while here in Thailand nobody cares.

 

But for sure i would need a lot of money for that trip because.... i could not pass the first Yamaha agent without making sure his RXZ spare part area is completely emptied into my luggage

 

Kind regards.....

 

Thanh

[Izammo]

Hi

 

The 2T adjuster is located between the end of the cable and the curved metal tube that leads to the 2T pump on the right side of the engine. Look at that curved metal tube (quite short), at it's end the black cable comes out that goes under the tank. Between the two is a hollow "screw" that is used to adjust the 2T intake - turn this screw just like you would turn a normal screw (8 or 9mm wrench required), if you screw it out of the curved tube you INcrease the 2T, if you screw it in you DEcrease the 2T. There is also a nut (10mm wrench required) to secure the adjuster screw after it is set.

 

The whole adjuster might be hidden under a rubber cap for protection against rain water.

 

The spark plug cap is a good one, i have been trying to find these in Thailand for well over two years and found it to be impossible - only fakes ("NCK") available, i finally got a genuine NGK via E-Bay Again i can't judge the rpice in Singapore, mine cost (per piece) 2.49 US$ and a spark plug (genuine NGK!) here in Bangkok cost around 35 Baht, roughly 1 US$.

 

Kind regards.....

 

Thanh

thanks Thanh, will look for the screw later, forgot to check for it just now.

 

glad to hear that's a good plug cap, cause whenever it rains heavily here, my bike will stall at the expressway, which is terrible cause traffic is crazy and i need to wave around to push my bike to the road shoulder..

[Thanh-BKK]

Hi.

 

Two possible causes (and solutions) for THAT problem - which i used to experience as well, and in my case it was NOT the spark plug cap!

 

First one could be the ignition coil. This is sitting under the tank, in the front of the frame. You can see it by following the spark cable. Splash water from your front wheel can get there and it can cause problems if the wires that lead to the coil get wet - there is only two wires and they connection can become loose, if water gets there it can fail even though the wires appear to be plugged together still. Easy remedy - unplug them (you need to remove the tank to get there!) and spray some WD-40 into the plugs before re-plugging. Also make sure that neither of the two wires is damaged and can touch some metal part like the frame itself.

 

In my case THIS WAS NOT THE PROBLEM EITHER, but something so stupid one has to find it first!

 

Look at your carb. In the bottom-rear of the carb is a small outlet to which a thin hose is connected. This hose disappears somewhere behind the engine.

 

That outlet and that hose serve three purposes - float bowl drain (if you open the screw on the bottom-left of the carb you can drain the float bowl of all petrol, eventual water and dirt inside), an overflow (excess petrol es discharged, for example when the floater hangs) and a pressure exchange - specially if you go fast, a small vacuum will be created in the float bowl and this outlet, then functioning as an inlet, allows for air pressure inside the float bowl to remain the same as outside.

 

This third function creates a problem under certain circumstances - if the hose from that outlet ends in the reach of splash water from the rear wheel, water can enter that hose and is sucked into the float bowl by the vacuum. This has two effects, both resulting in the same problem ultimately - water will slowly accumulate inside the float bowl until it is enough to sit in the main jet where it (it is heavier than petrol!) will not go through, and also it keeps the vacuum inside the float bowl strong enough to allow less petrol to go through the main jet.

 

In both cases, the engine will stall for lack of petrol. And you will find yourself kicking and kicking and kicking and..... until the bike suddenly starts again and appears to be running normal - for a few 100 meters when the same problem occurs again.

 

Solution: Open the screw on the bottom-left of the carb to drain the float bowl (petrol **** closed!), after it is empty, open the petrol **** for a few seconds to flush the float bowl and the hose. Close petrol **** and that screw, open petrol **** again, wait a few seconds and you are good to go.

 

To prevent it from happening again, shorten the hose that goes from the carb outlet and position it in such a way that splash water can not reach it, however do NOT route it to end higher than the float bowl! That would prevent it to function as an overflow which could result in a flooded engine (which, stupidly, has very similar effects - engine stalls and is hard to start again).

 

I came to this result after going through several spark plug caps and various measures to make sure the ignition coil stays dry - after washing my bike with a garden hose while the engine was running. And, sure enough - ever since i shortened the hose and laid it in such a way that it ends behind the engine, yet not low enough to be touched by water, my RXZ never even stalled ONCE again, regardless how much it was raining.

 

By the way - a short-term remedy in case it happens to you while on the expressway or some place where you can't stop and you feel the bike wants to stall - pull out the choke and keep riding.

 

Kind regards......

 

Thanh

[Thanh-BKK]

Hello again.

 

Stupid censoring - those "****" mean petrol c_o_c_k, the one under the tank that makes the petrol flow or stop. Is there another word for it that is not getting censored?

 

Kind regards.....

 

Thanh

[Izammo]

Hi.

 

Two possible causes (and solutions) for THAT problem - which i used to experience as well, and in my case it was NOT the spark plug cap!

 

First one could be the ignition coil. This is sitting under the tank, in the front of the frame. You can see it by following the spark cable. Splash water from your front wheel can get there and it can cause problems if the wires that lead to the coil get wet - there is only two wires and they connection can become loose, if water gets there it can fail even though the wires appear to be plugged together still. Easy remedy - unplug them (you need to remove the tank to get there!) and spray some WD-40 into the plugs before re-plugging. Also make sure that neither of the two wires is damaged and can touch some metal part like the frame itself.

 

In my case THIS WAS NOT THE PROBLEM EITHER, but something so stupid one has to find it first!

 

Look at your carb. In the bottom-rear of the carb is a small outlet to which a thin hose is connected. This hose disappears somewhere behind the engine.

 

That outlet and that hose serve three purposes - float bowl drain (if you open the screw on the bottom-left of the carb you can drain the float bowl of all petrol, eventual water and dirt inside), an overflow (excess petrol es discharged, for example when the floater hangs) and a pressure exchange - specially if you go fast, a small vacuum will be created in the float bowl and this outlet, then functioning as an inlet, allows for air pressure inside the float bowl to remain the same as outside.

 

This third function creates a problem under certain circumstances - if the hose from that outlet ends in the reach of splash water from the rear wheel, water can enter that hose and is sucked into the float bowl by the vacuum. This has two effects, both resulting in the same problem ultimately - water will slowly accumulate inside the float bowl until it is enough to sit in the main jet where it (it is heavier than petrol!) will not go through, and also it keeps the vacuum inside the float bowl strong enough to allow less petrol to go through the main jet.

 

In both cases, the engine will stall for lack of petrol. And you will find yourself kicking and kicking and kicking and..... until the bike suddenly starts again and appears to be running normal - for a few 100 meters when the same problem occurs again.

 

Solution: Open the screw on the bottom-left of the carb to drain the float bowl (petrol **** closed!), after it is empty, open the petrol **** for a few seconds to flush the float bowl and the hose. Close petrol **** and that screw, open petrol **** again, wait a few seconds and you are good to go.

 

To prevent it from happening again, shorten the hose that goes from the carb outlet and position it in such a way that splash water can not reach it, however do NOT route it to end higher than the float bowl! That would prevent it to function as an overflow which could result in a flooded engine (which, stupidly, has very similar effects - engine stalls and is hard to start again).

 

I came to this result after going through several spark plug caps and various measures to make sure the ignition coil stays dry - after washing my bike with a garden hose while the engine was running. And, sure enough - ever since i shortened the hose and laid it in such a way that it ends behind the engine, yet not low enough to be touched by water, my RXZ never even stalled ONCE again, regardless how much it was raining.

 

By the way - a short-term remedy in case it happens to you while on the expressway or some place where you can't stop and you feel the bike wants to stall - pull out the choke and keep riding.

 

Kind regards......

 

Thanh

 

that was a lot of detail. but im pretty sure its the cap, cause the moment i check that area when it stalled, the cap was loose and when i try to pluck it into the plug, it does not seem to have a catch and wont remain tight together. (Sorry bad english)

 

as for the screw at the carb, the only screw i know is the idling one. i may need to check on that too.

 

as for the hose, is it the one where one end connects to carb, the other end is a loose one, not connected to anything?

[Thanh-BKK]

Hi

 

Hmm i understand your English very well, no problem Yeah if the spark plug cap is loose you should put a new one there..... it is also important that the rubber seal on both ends of the cap are intact.

 

As to the screw, actually your carb has three of them, all reachable from the left side. The big one that you can turn by hand is for idle, the small one on the carb's body is for idle air mixture and the one i was talking to is on the very bottom of the carb, under the float bowl. This is a philips screw ("cross").

 

As for the hoses, again you will find altogether five hoses on the carb - the thick one for the petrol (left side), another thin one (left side), a thin one right side-front (2T intake) and yet another thin one right side. But the one i am talking about is the open-ended one that leaves the carb on it's rear side-bottom, near the mentioned screw.

 

I still had a photo of one of my carbs, sadly with that exact hose missing so i painted it in red, please have a look.

 

Kind regards......

 

Thanh

[Izammo]

Hi

 

Hmm i understand your English very well, no problem Yeah if the spark plug cap is loose you should put a new one there..... it is also important that the rubber seal on both ends of the cap are intact.

 

As to the screw, actually your carb has three of them, all reachable from the left side. The big one that you can turn by hand is for idle, the small one on the carb's body is for idle air mixture and the one i was talking to is on the very bottom of the carb, under the float bowl. This is a philips screw ("cross").

 

As for the hoses, again you will find altogether five hoses on the carb - the thick one for the petrol (left side), another thin one (left side), a thin one right side-front (2T intake) and yet another thin one right side. But the one i am talking about is the open-ended one that leaves the carb on it's rear side-bottom, near the mentioned screw.

 

I still had a photo of one of my carbs, sadly with that exact hose missing so i painted it in red, please have a look.

 

Kind regards......

 

Thanh

thanks, you are very informative!

 

oh ya, the mechanic made sure the seals are tight and intact.

 

anyway, i think i know what hose is it, once, my petrol flow out from there whenever i turn on my petrol ****, and im not sure why, didnt get it to check at any mech, i just continued riding as per normal, only to off the **** whenever i park, but now its okay. you got any idea? is it cause of the overflow you were talking about in your earlier posts?

[Thanh-BKK]

Hi.

 

Yes, that happens because of the overflow. Now why DOES it over flow? Normally the floater's job is to make sure exactly that does not happen.

 

However what often happens is that a small piece of dirt or rust gets between the floater walve needle and it's seat (that is inside the carb) and there it prevents the valve from closing properly, hence the petrol will flow out.

 

If the carb is old, the floater valve needle can be worn out, too (it has a rubber tip) and may need replacing. This is a small part which should be quite cheap.

 

Another possibility is the floater itself getting stuck, that happens some times - if the petrol flows out and you knock the outside of the float bowl with a screwdriver or something and it stops flowing, then this was the cause The floater can also become stuck in the "closed" position which is quite stupid - you ride off and after 100 meters or so the engine will turn off and not start again. First time this happened to me i looked everywhere except the carb..... as i found that after some pushing (due to the vibrations!) the floater became un-stuck and it all worked again.

 

Now, if it happens again, i just tap the outside of the carb (while still sitting on the bike) and it usually will work, but it happens rarely.

 

Kind regards.....

 

Thanh

[hadisons]

hi bro....help.....urgently looking for japan /malaysia rxk....coe left 2years ok .....pls cal me 91090126

[wantongkol07]

hey bros. sorry im new to rxz and i've been asking alot of questions, and might irritate some of you guys. i would like to learn more about rxz.

bros, have you guys tried bigger carbs on rxz? eg. use sp carb, krr carb ect. and whats the biggest size you've tried. and hows the performance? thanks in advance.

[syamitomo]

hey bros. sorry im new to rxz and i've been asking alot of questions, and might irritate some of you guys. i would like to learn more about rxz.

bros, have you guys tried bigger carbs on rxz? eg. use sp carb, krr carb ect. and whats the biggest size you've tried. and hows the performance? thanks in advance.

 

I think tat topic had already been talk about a few pages back. Browse through the RXZ Lovers pages bro and hopefully your questions will be answered!!!

[Ru-D]

hi guys.. im riding a 1st hand rxz. but few problems dat i cudnt solve. hope u guys out they can help me.

1. bike very hard to start. must turn on choke all the time. warm up very slow. but once warm up alredy, bike no problem.

 

Take note that spark plug has been replaced to new ones. Carb serviced. And its first hand!

[Izammo]

hey syam, finally get to meet. and thanks for the tayar again, hope to meet up again to clean up my bike eh? haha.

[syamitomo]

hey syam, finally get to meet. and thanks for the tayar again, hope to meet up again to clean up my bike eh? haha.

 

Ahakz... Yeah, FINALLY!!! Hahaha... Yup2!

[syamitomo]

.... and also i am planning to have a third RXZ one day, that one i want to make into a scrambler type of bike (off-road). RXZ are very versatile due to their engine - that engine has a lot of torque while at the same time also able to rev high and generate a lot of horse power, specially with a little porting.... and because it lacks such "high tech" features like YPVS or similar it is very easy to work on.

 

Thanh

 

Bro!!! Ur scrambler-type-RXZ......

 

[Ru-D]

hi guys.. im riding a 1st hand rxz. but few problems dat i cudnt solve. hope u guys out they can help me.

1. bike very hard to start. must turn on choke all the time. warm up very slow. but once warm up alredy, bike no problem.

 

Take note that spark plug has been replaced to new ones. Carb serviced. And its first hand!