cold start problem

[oceanb70]

Ok... I got cold start problem, very serious problem.

 

My engine doesn't perform like before. Last time one start only, sure start. Now will start but engine die within 5sec. Then I went to wash my carb and KNN at planet. after wash, the problem become worst....

 

now i start, within 2sec die.. start a few times also same. must hold my throttle to let the idling speed to 1k rpm for 1min. if i don't hold, the rpm is around 400rpm. I told ah chong@planet, he tune the rpm to higher which doesn't solve the problem.

 

yes, the bike didn't die at morning but when engine get hot... the rpm is around 2k rpm which always cause overheat very easily.

 

now my question is.. any maintenance did i miss? I am not very good in maintaining bike.

 

i always do change EO,spark plug, engine filiter,.....etc

 

another question, what doesn't the choke do for s4? seem like useless...

[Ah Pek]

start, within 2sec die.. start a few times also same. must hold my throttle to let the idling speed

 

Let us walk thru with this one...See if there is a small rubber tubing running one end from your fuel **** to the left upper backside of your block is plug in...or even missing. One end plug ibto the fuel cok and the other end to the snout back upper left of your engine block.

[oceanb70]

able to see without taking out anything???

 

so, should it be plug in or out? what's that rubber tubing for?

[skateboy]

its raining very often lately. could it b water in the fuel tank? spark plugs burnt due to water contamination?

 

seems like combustion got prob. unable to maintain ideal rpm at initial startup. since carb n air filter is serviced, wat left for combustion is fuel n plugs.

[oceanb70]

could it be due to tuning?? i nv done any re-tune before after i bought this bike 2 yr ago...

[oceanb70]

its raining very often lately. could it b water in the fuel tank? spark plugs burnt due to water contamination?

 

seems like combustion got prob. unable to maintain ideal rpm at initial startup. since carb n air filter is serviced, wat left for combustion is fuel n plugs.

actually.. i don't really understand... where is combustion?? need to change spark plug only??

[Ah Pek]

able to see without taking out anything???

 

so, should it be plug in or out? what's that rubber tubing for?

 

Nothing to take out...just look at your fuel co*k...there is a small tube and just make sure the other end is plug into engine block...its your vaccum tube that pulses your fuel co*k diaphgram.

[Winners]

Change to a new set of spark plugs and see what happens after that.

[skateboy]

actually.. i don't really understand... where is combustion?? need to change spark plug only??

 

combustion is a process when fuel n air mixed, compressed by the piston, spark from plug to produce power. there must b a certain amount of air n fuel in order to maintain a stable idling. air filter is serviced so air shd not b a prob. now left with spark plug n fuel.

[JbAtRaCeR]

oceanb70:- Bro can give inputs on ur bike's current mileage,any overhaul done. Its sound abit like compression problem. Since you get the carbs checked. As for the choke in S4,we live in SG,manual says to use it only on temperatures you find in Genting. What the choke does is cut the air ratio abit,when you starting the bike thus by having more fuel in the air/fuel ratio,the bike starts easier.

[oceanb70]

mileage now is around 115000. I think should be spark plug as my last replacement is 20000km ago. Iridium.. i will update again.

 

and also.... around 2week ago, before i service my carb.. i got overheat problem, Fan don't move when engine hot. According to planet, he suspect my radiator spoilt(but i just change 1.5year ago which cost me $360) as the heat with radiator and engine not same... one cold one hot.. So after some discussion, he decided to change the coolant water to test first(i changed coolant water 6month ago). And it works...

 

but lately, i discover the radiator leak coolant water..... how ar?? must change??

[skateboy]

the coolant pump working? radiator how come so fast leak? mayb due the improper circulation that cause irregular expansion n contraction so end up got hairline crack on the radiator thus coolant leak. do go back to planet to ask how come radiator leaking. n do find the location of the leak. if its from any loose fittings, still ok. if not, i dunno how oso.

[oceanb70]

later ask me to change radiator.... $400 this time... sad...

[skateboy]

ur bike how old already? they ask u to change, u can say not now. unless they can b very sure that that is the prob then nevermind, change.

[Ah Pek]

later ask me to change radiator....

 

If your radiator is really screwed this time again...go have it refurbished (yes..can be repaired..not much people know)...much lighter on your pocket.

 

Hush..hush here, but there are ppl who collect 'waste' radiator and does a good job out of it and sell as second..and they are all as reliable as a new one.

[rayhunter]

If your radiator is really screwed this time again...go have it refurbished (yes..can be repaired..noy much people know)...much light on your pocket.

 

that's a good tipoff..

hope when request for this service,dun get rejected by the mechanics who do not know how to do it..

[JbAtRaCeR]

Its true that in SG there's not much mech who can do radiator repair jobs. Need to scout because there is only a handful of them. Iridium plugs at 20 000km?..Maybe thats it. I'm also using iridum ones currently(10 000km) when engine is hot starting will be abit hard,need to crank twice to start engine.

[ZzGaNgStErzZ]

Planet does repair the radiator(send to other mechs), so no need to scare ah chong say cant repair. he will advise u de.

[oceanb70]

thanks for your advice.. will update you guys on the status again

[amano]

When Engine is hot, it will be a warm start. Need to throttle a bit when starting it. If cold start, try not to throttle. Just press ign button and let it run itself. If cant start properly, likely carb tuning out or spark plug weak liao. My normal NGK plug can last up till 30000Km.

 

For cold start can try CR9 instead of CR8 for NGK Plug. If denso plug, use only Iridium. Other than iridium, not as fantastic as NGK.

[excuse]

bro i got the exact same problem as u ... no matter morning or night as long as it is the 1st start the engine can start ... but will die within 2 seconds

 

i got to maintain the throttle at 1k rpm for about 5-10secs before the engine wont die . even then sometimes it will still die off

 

maybe u can share how u solved ur problem here ...

[I_Ride_A_Bike]

When Engine is hot, it will be a warm start. Need to throttle a bit when starting it. If cold start, try not to throttle. Just press ign button and let it run itself.

 

its the opposite? ..engine hot so no need to throttle to warm up bike, and engine will not die off cuz its already up and running previously.

 

engine cold then need to warm up - hence the reason why pple leave their cars/bikes to 'warm up' esp in the morning by turning on the engine to run a few mins then move off..

[skateboy]

bro i got the exact same problem as u ... no matter morning or night as long as it is the 1st start the engine can start ... but will die within 2 seconds

 

i got to maintain the throttle at 1k rpm for about 5-10secs before the engine wont die . even then sometimes it will still die off

 

maybe u can share how u solved ur problem here ...

 

is ur idling too low?

[oceanb70]

ok... Some updates on my bike.

 

I mentioned the radiator leak.. It's actually the pipe from radiator to engine that bust. So it leak until coolant dry and the cold start problem gone. Coincidentally there are very cold weather last week. The cold start problem gone after the cold weather days. So i don' t know is the coolant water leak finish that solve the problem or cold weather days save my bike. Now i got no problem on the cold start.

 

But still, i got my pipe replace and also spark plug changed. Total damage : $120.

 

$72 - spark plug

$38 - water pipe

$10 - Coolant water

[Ah Pek]

ok... Some updates on my bike.

 

I mentioned the radiator leak.. It's actually the pipe from radiator to engine that bust. So it leak until coolant dry and the cold start problem gone. Coincidentally there are very cold weather last week. The cold start problem gone after the cold weather days. So i don' t know is the coolant water leak finish that solve the problem or cold weather days save my bike. Now i got no problem on the cold start.

 

But still, i got my pipe replace and also spark plug changed. Total damage : $120.

 

$72 - spark plug

$38 - water pipe

$10 - Coolant water

 

Good news.. at leats all is solve for good and having parts replacemente tc..comes to $120 is worth the problem/problems solved. Enjoy your ride and stay safe mannn!