[Discussion] General Queries From Newbies

[Sadnewbie]

Dear Riders,

 

Would like to seek your kind advice for some problems which I'm facing currently:

 

My very old Honda Phantom TA200 just finished a pretty major servicing at Ah Chong's Planet Motors recently to change the gearbox (changed gears 2-6), changed a few engine gaskets, changed cam-chain-tensioner, spark plug, engine oil.

 

However after that, I realised that my bike will backfire often when closing throttle (e.g. when stopping or even every time I change gear). This happens more often when the engine is hot, i.e. that means there is no backfire for the first 5-10mins of riding, but it will start after that. I can reduce it a little by trying to close throttle slower and by controlling clutch, but it will still happen abit. The backfire is not very loud, more like a soft pop/cough sound.

 

I also realise that the throttle feels very spongy and no power at higher RPMs. i.e. when changing gear the initial pickup is okay, but when get to cruising RPM at 6th gear, really no power. I can change to 6th gear and only get 70kmph (!) at a low RPM (i.e. engine not stalling, clutch properly engaged).

 

Based on some readings, I suspect that the problem is that my fuel-air mixture is too rich. And I would like to tweak by adjusting the carburetor. But unfortunately I can't find any info on it anywhere on the forum/internet after searching for quite a long time. Can anyone please help me?

 

Thank you very much.

 

Bro, I'm no expert and in fact very newbie so take what I say with a huge pinch of salt. For what it's worth, I read that the back firing is caused by mixture too lean causing misfires when deaccelerating and the next fire ignites the unburnt petrol which went to the exhaust due to misfire. Too rich mixtures does not misfire. That said, I'm trying to find that adjustment screw myself.

[Sadnewbie]

Hi bros, can anyone advise is this fuel-air mixture screw?

[Sadnewbie]

Or is it this? There's a VE marking beside it

[naim]

Bro, I'm no expert and in fact very newbie so take what I say with a huge pinch of salt. For what it's worth, I read that the back firing is caused by mixture too lean causing misfires when deaccelerating and the next fire ignites the unburnt petrol which went to the exhaust due to misfire. Too rich mixtures does not misfire. That said, I'm trying to find that adjustment screw myself.

 

correction. rich mixture causes backfire because of the excess fuel.

 

Hi bros, can anyone advise is this fuel-air mixture screw? [ATTACH=CONFIG]264593[/ATTACH]

 

that is the idle adjustment screw. it will only affect ur idling. to adjust ur actual A/F mixture wen u are riding, u nd to dismantle the carb and change jets or adjust the needle.

[Sadnewbie]

correction. rich mixture causes backfire because of the excess fuel.

 

 

that is the idle adjustment screw. it will only affect ur idling. to adjust ur actual A/F mixture wen u are riding, u nd to dismantle the carb and change jets or adjust the needle.

 

Thanks bro Naim for the correction.

 

Just to reconfirm about the mixture screw, I was referring to the screw that I circled and which can only be adjusted with screwdriver, and not the big one that can be turned with fingers.. is that small screw also the idling screw? Does that mean there are two screws to adjust idling?

[naim]

Thanks bro Naim for the correction.

 

Just to reconfirm about the mixture screw, I was referring to the screw that I circled and which can only be adjusted with screwdriver, and not the big one that can be turned with fingers.. is that small screw also the idling screw? Does that mean there are two screws to adjust idling?

 

the one u circle must use screwdriver. dat one affects the air/fuel ratio at idling. the big one changes the idling speed. if no problems wif ur idling and starting, no need to adjust lar.

[Sadnewbie]

Oic... Thanks bro for always helping out here By the way do you have any idea what is the screw on the 2nd attachment with the VE marking beside it?

 

I am having problems with idling so maybe need to tinker with the mixture a bit... sometimes stall at traffic lights which is very stressful with a line of vehicles waiting behind I can hear some loud clicking right before it stalls.. Is that misfiring sound? If during the clicking I manage to rev the throttle hard then it sometimes saves the stall but will move with noticeable spluttering. Sometimes the clicks is just a few times before it stalls so there's nothing I could do. Any advise which screw I should play around with? The problem is it doesn't happen all the time.. when I brought it to planet, Ah Chong rode two rounds and say nothing wrong... :s

Edited December 8, 2012 by Sadnewbie

[ezzyoiler]

idling can be adjusted by a big plastic knob..on the right side of carb...this act as a stopper to the throttle minimum position.adjust knob is just moving stopper higher or lower...try it then u will know.

 

the other fuel mixture screw..look arounf sure u can find it..how to adjust it??

if you have a rpm metr or tacho..it is easy..on a phantom this is what i will do..

 

make sure bike is warm up as after a ride..do not adjust when bike is cold.

 

turn idling knob to increase rpm..say 2k..or by ear hear rpm goes up ...xxx

now look at fuel mix screw position..dont forget the original position,if u screw up u can reset to what it it was.

 

at a higher idling the bike will be reving away...turn fuel mix screw clockwise or anti clock wise..try one direction first..

what we are looking for is an increase in rpm...if it increase rpm slowly turn until you reach the maximum...

then back off 1/2 to 1 turn..up to you...

note you should be counting how many many turns to achieve max rpm..

at the max rpm setting ...it is bloody lean thats the reason to back off 1/2 to 1 turn...ie adjust how lean or rich with this screw

if u mess up go back to oringnal setting ...thats the reason you are counting the turns u make..

after the fuel mix is adjusted as to your requirements...

lower the idling rpm...

test ....rev up and down...see whether the bike is reponding to your requirements..if not adjust fuel mix screw again..and again until you are satisfied..

test ride...you want back fire..evo wrc rumbling..etc etc..u can do it with the fuel mix screw..or just great perfomances it is up to you.

 

too complicated..call me and we can do it toether...a cup of coffee is my fees..

[ezzyoiler]

anyone needs help..come over...

[Sadnewbie]

idling can be adjusted by a big plastic knob..on the right side of carb...this act as a stopper to the throttle minimum position.adjust knob is just moving stopper higher or lower...try it then u will know.

 

the other fuel mixture screw..look arounf sure u can find it..how to adjust it??

if you have a rpm metr or tacho..it is easy..on a phantom this is what i will do..

 

make sure bike is warm up as after a ride..do not adjust when bike is cold.

 

turn idling knob to increase rpm..say 2k..or by ear hear rpm goes up ...xxx

now look at fuel mix screw position..dont forget the original position,if u screw up u can reset to what it it was.

 

at a higher idling the bike will be reving away...turn fuel mix screw clockwise or anti clock wise..try one direction first..

what we are looking for is an increase in rpm...if it increase rpm slowly turn until you reach the maximum...

then back off 1/2 to 1 turn..up to you...

note you should be counting how many many turns to achieve max rpm..

at the max rpm setting ...it is bloody lean thats the reason to back off 1/2 to 1 turn...ie adjust how lean or rich with this screw

if u mess up go back to oringnal setting ...thats the reason you are counting the turns u make..

after the fuel mix is adjusted as to your requirements...

lower the idling rpm...

test ....rev up and down...see whether the bike is reponding to your requirements..if not adjust fuel mix screw again..and again until you are satisfied..

test ride...you want back fire..evo wrc rumbling..etc etc..u can do it with the fuel mix screw..or just great perfomances it is up to you.

 

too complicated..call me and we can do it toether...a cup of coffee is my fees..

 

Wow! Thanks for the long and detailed step by step instructions!

I've looked around the carburetor and only found 2 screws which look like they are possibly mixture screws. Can I trouble you a little bit more to look at the previous 2 attachments a few posts up to help identify which one is it? Is it the one at the right side of bike at bottom of carburetor (without any markings) or the one on the left side of the bike (with a marking that says "VE")?

 

2nd question I have is the necessity to adjust rpm higher to lets say 2k before adjusting mixture.. would there be a difference if I warm up the bike and then adjust the mixture itself and listen for a increase in rpm to max and then back it out like you said? This second question is just for curiosity, I will try to follow your instructions step by step but I don't have a tachometer at the moment...have ordered one but I'm itching to start tuning not sure if I can manage to hold back till it arrives..

Edited December 8, 2012 by Sadnewbie
additional query

[ezzyoiler]

back firing....it is a very loud explosion...

if it is the first time you are experiencing this..you will definitele be shock..

back firing can kill the engine...end up servicing and or replacing expensive parts..

[ezzyoiler]

Wow! Thanks for the long and detailed step by step instructions!

I've looked around the carburetor and only found 2 screws which look like they are possibly mixture screws. Can I trouble you a little bit more to look at the previous 2 attachments a few posts up to help identify which one is it? Is it the one at the right side of bike at bottom of carburetor (without any markings) or the one on the left side of the bike (with a marking that says "VE")?

 

2nd question I have is the necessity to adjust rpm higher to lets say 2k before adjusting mixture.. would there be a difference if I warm up the bike and then adjust the mixture itself and listen for a increase in rpm to max and then back it out like you said? This second question is just for curiosity, I will try to follow your instructions step by step but I don't have a tachometer at the moment...have ordered one but I'm itching to start tuning not sure if I can manage to hold back till it arrives..

 

i have sold my phantom 3 years ago...cant remember..so sorry.

but just test it...once again count the no. of turns you make.

if it does not respond back to original setting..

 

 

it is necessar to move rpm higher with idling adjustment...so the engine can respond faster and you can hear it distincly..

or else it takes a very experience ear to figure out..

[ezzyoiler]

if yours is an old bike...might as well remove the bowl of the carb...check for debri or water....test float by pushing it up and let it fall.

this also can clear debri atuck at the float valve..but be gentle..

 

if there is debri...your tank could be rusting...

if it indeed has...drain tank ..into pail or something...there should be debri setting at the bottom..

[Sadnewbie]

if yours is an old bike...might as well remove the bowl of the carb...check for debri or water....test float by pushing it up and let it fall.

this also can clear debri atuck at the float valve..but be gentle..

 

if there is debri...your tank could be rusting...

if it indeed has...drain tank ..into pail or something...there should be debri setting at the bottom..

Thanks bro for the explanation on why need to increase rpm, as for checking and cleaning the float bowl, I can just turn off the fuel using the fuel "tap" and unscrew the bowl directly without removing the whole carburetor right? Is it just straightforward unscrew the bolts and pull down? Any springs that can jump out that a first timer might not know how to put back? Also the gasket won't spoil right?

Edited December 9, 2012 by Sadnewbie

[naim]

I dont tink its easy to remove the bowl wif the carb still attached to the engine because the screws are directly under). Better to remove the entire carb, dismantle everyting, clean up n check for any torn diaphragm. Its not that hard. Just need to remove the throttle cable, airbox tube (accessible from right side chrome cover), unplugging all the hoses (just take note of which hose go whr) then loosen the front clamp and the carb can take out alr.

[ezzyoiler]

gasket...

be gentle when you have gaskets...off course if you damage it..need to replace.

just bolts ....

[epidemic41]

hi guys. does anyone know how to turn on the brake light? mine only seems to light up when i press the back brake. at idling and when pressing the front brake it doesnt. doesnt seem to be a faulty bulb so maybe someone can give some advice? much appreciated!

[Sadnewbie]

Thanks naim and ezzyoiler, guess I'll not try to take out for now until I'm feeling adventurous Thanks so much for all the help.

[Sadnewbie]

hi guys. does anyone know how to turn on the brake light? mine only seems to light up when i press the back brake. at idling and when pressing the front brake it doesnt. doesnt seem to be a faulty bulb so maybe someone can give some advice? much appreciated!

 

Before anyone can give you more sound advise, my take is just replace the bulb if you're not sure... it's very easy cos even I can do it. Cost was cheap like $2-$3 If that didn't work try opening the headlights and you will see many wires inside.. move them around, unplug and plug back etc. Might do the trick! Worked for my signal lights anyway..

[ezzyoiler]

hi guys. does anyone know how to turn on the brake light? mine only seems to light up when i press the back brake. at idling and when pressing the front brake it doesnt. doesnt seem to be a faulty bulb so maybe someone can give some advice? much appreciated!

 

if the the foot pedal works...and the front handbrake does not work...suggest u check the micro switch which is actuated by the front brake lever. either the actuation is out or the micro switch is defective..yhis is most likely the cause

[epidemic41]

if the the foot pedal works...and the front handbrake does not work...suggest u check the micro switch which is actuated by the front brake lever. either the actuation is out or the micro switch is defective..yhis is most likely the cause

 

hey thanks for replying so quickly. i tinkered abit with the brake switch at the front and the brake lights suddenly came on. but ya i have to change the switch cuz the knob has broken off. appreciate yr insights man!

[Sadnewbie]

Sorry about my unuseful advise... somehow read it as idling lights doesn't work but braking does, which is what happened to me before... paisei paisei..

[epidemic41]

Sorry about my unuseful advise... somehow read it as idling lights doesn't work but braking does, which is what happened to me before... paisei paisei..

 

lol that is exactly the same problem as i am facing now. how did u solve it?

[Sadnewbie]

lol that is exactly the same problem as i am facing now. how did u solve it?

I was lucky.. changed the light bulb and then solved

[ahch0ng]

I was lucky.. changed the light bulb and then solved

 

just kenna this recently..

 

just change bulb and it worked~