[Hashim]

I own a Yamaha Gladiator DX 2006 model and I am facing problem with idle since last 2 years. Here is the whole story:

Little bit of history
------------------
When the bike was new, I remember I could start in chilling december morning with single self, open choke to warm up and the bike would run fine, however after few years I noticed the bike will not keep optimum idle when engine was cold and shut off (due to low RPM) and after running when engine was hot enough, it would idle at much faster rate and when checked at was found to be around 3000 RPM. In next service I reported the problem and they did carb cleaning but it did not help. Next thing they did was opening some screws in engine and doing some setting there, I have marked the three things the mechanic opened in image below:



After this the problem was solved and bike will start and idle well in cold as well as when hot but I felt something was still not just right and engine was not smooth as it was before.

Now there is new problem
------------------------

Bike will sometime start in single self or kick and idle well but after few second idle get abnormal, it will become very low itself then again return to normal, now the moment idle speed becomes low and I move throttle (even slightest move) the engine will cut off! Next problem to this is when engine cut off like this, it will not easily start and need a looong self! and just refuse to start using kick so I don't bother using kick when this happen.

Real problem is when I am in traffic slowly moving and throttle is at closed position, the moment I try to move, engine cut off so I have to keep revving so that engine does not reach that "low" idle RPM when engine will cut off.

Things about my bike that might help expert to diagnosis problem:
---------------------------------------------------------------
- Bike is used less, it has run only 4519 KM since Sep. 2006
- Airfilter is clean (I myself cleaned it with petrol few days back to check if this solves the problem)
- Petrol is good as we get it from my university owned fuel station where there is no adulteration.

[somspaple]

engine cutting-off on and irregular idling: this seems to be a problem with the carb. if 'm not wrong engine cuts off when you try to twist the throttle gently but it is all fine once it 'passes' the cut-off zone: correct?

[Hashim]

Originally Posted by somspaple

if 'm not wrong engine cuts off when you try to twist the throttle gently but it is all fine once it 'passes' the cut-off zone: correct?

correct, can it be problem with TPS too? because earlier cleaning of carb didn't help at all.

[somspaple]

Originally Posted by Hashim

correct, can it be problem with TPS too? because earlier cleaning of carb didn't help at all.

no idea : don't think so. this looks like more of a problem with the carb. my friend had a similar problem and as per your post earlier when the carb was cleaned you did not have this problem right? have you checked with your mechanic after this . or try swapping the carb of some other Gladi to check.

[aaggoswami]

1) I am facing similar problem in my Suzuki Zeus. I mean exactly the same idling issue. Zeus was bought in May 2007, right now its around 139XX kms. I have this issue from day one. No amount of queries are able to help. Unstable idling = valve setting required, this is generally true. But in your case and even in my case, valve setting is of no use.

2) I recently paid Rs. 450 for slider top of my Carb, they called it as slider piston or something. Want to know the problem ? When I opened the throttle fully, the throttle would be struck there. Yes, the throttle would be struck fully open. I almost crashed when this happened. Thankfully I engaged clutch on time.
After the bike was shut when I reached destination, the throttle was fully open, and now the bike wont start.

This must happen. SA here told me that this is the first case in 15 years of his career. What I know is that this must not happen anytime. I have used other two wheelers, but this problem never came up. I paid Rs. 1246/- for a bike run 139xx kms. Total expenditure on bike is Rs. 4160/- till date, and this figure is without the free service.

3) How is this connected to the idling issue.

Well, to check if my carb is OK or not after replacing just a pin worth Rs. 170/- rather than the entire part of Rs. 450/-, they did some jumbling with my carb. Other bike's carb was temporarily installed in my bike. Here also I noticed that idling was not stable.

So, with two carbs my bike was not idling in stable manner. The problem is not carb IMHO. If carb were a problem, then why after valve adjustment your bike was idling well for a few days ?

Please not that my more than 85K kms. used Caliber never had such an issue with idling. Again the current generation of bikes do give a lot of problems. My friend's FZ has similar issue of unstable idling.

[Jaggu]

Completely dismantle the carb and clean it inside out, ensure all the venturies are clean. Check/Clean/replace jets and float pin's. See if the problem is resolved. Ensure that throttle cable and choke are also working fine and smooth. Start the vehicle and tune the carb to stock settings, mechs have a tendency to lean it out for better mileage.

If this doesnt sort out move on to valve setting (do it when cold) the round thing on top, also check if the timing belt cam etc are set properly. Double check the timing using timing light and ensure the advance is working fine.

Ensure airfilter/spark plug is clean or plonk in new one, double check for any air leaks.

How many kms the engine has done?

[sportz_kruzer]

Originally Posted by aaggoswami

1) I am facing similar problem in my Suzuki Zeus. I mean exactly the same idling issue. Zeus was bought in May 2007, right now its around 139XX kms. I have this issue from day one. No amount of queries are able to help. Unstable idling = valve setting required, this is generally true. But in your case and even in my case, valve setting is of no use.

2) I recently paid Rs. 450 for slider top of my Carb, they called it as slider piston or something. Want to know the problem ? When I opened the throttle fully, the throttle would be struck there. Yes, the throttle would be struck fully open. I almost crashed when this happened. Thankfully I engaged clutch on time.
After the bike was shut when I reached destination, the throttle was fully open, and now the bike wont start.

This must happen. SA here told me that this is the first case in 15 years of his career. What I know is that this must not happen anytime. I have used other two wheelers, but this problem never came up. I paid Rs. 1246/- for a bike run 139xx kms. Total expenditure on bike is Rs. 4160/- till date, and this figure is without the free service.

3) How is this connected to the idling issue.

Well, to check if my carb is OK or not after replacing just a pin worth Rs. 170/- rather than the entire part of Rs. 450/-, they did some jumbling with my carb. Other bike's carb was temporarily installed in my bike. Here also I noticed that idling was not stable.

So, with two carbs my bike was not idling in stable manner. The problem is not carb IMHO. If carb were a problem, then why after valve adjustment your bike was idling well for a few days ?

Please not that my more than 85K kms. used Caliber never had such an issue with idling. Again the current generation of bikes do give a lot of problems. My friend's FZ has similar issue of unstable idling.

Your case ssems to be of the valves gone bad. I feel its a leaky intake valve. suggest you get it disassembled and checked.

[sportz_kruzer]

Originally Posted by Hashim

I own a Yamaha Gladiator DX 2006 model and I am facing problem with idle since last 2 years. Here is the whole story:

Little bit of history
------------------
When the bike was new, I remember I could start in chilling december morning with single self, open choke to warm up and the bike would run fine, however after few years I noticed the bike will not keep optimum idle when engine was cold and shut off (due to low RPM) and after running when engine was hot enough, it would idle at much faster rate and when checked at was found to be around 3000 RPM. In next service I reported the problem and they did carb cleaning but it did not help. Next thing they did was opening some screws in engine and doing some setting there, I have marked the three things the mechanic opened in image below:

Attachment 303805

After this the problem was solved and bike will start and idle well in cold as well as when hot but I felt something was still not just right and engine was not smooth as it was before.

Now there is new problem
------------------------

Bike will sometime start in single self or kick and idle well but after few second idle get abnormal, it will become very low itself then again return to normal, now the moment idle speed becomes low and I move throttle (even slightest move) the engine will cut off! Next problem to this is when engine cut off like this, it will not easily start and need a looong self! and just refuse to start using kick so I don't bother using kick when this happen.

Real problem is when I am in traffic slowly moving and throttle is at closed position, the moment I try to move, engine cut off so I have to keep revving so that engine does not reach that "low" idle RPM when engine will cut off.

Things about my bike that might help expert to diagnosis problem:
---------------------------------------------------------------
- Bike is used less, it has run only 4519 KM since Sep. 2006
- Airfilter is clean (I myself cleaned it with petrol few days back to check if this solves the problem)
- Petrol is good as we get it from my university owned fuel station where there is no adulteration.

This is a classic case of burnt valves. The intake valve has worn and has gone deeper in to the seat. Also its not forming a good seal for ideal compression to take place. Have you tuned the bike lean for more mileage? Does the engine overheat?

PS: The screws fiddled by the A.s.s in the picture shows that he has checked the valve timing and chain tension. Not much to do there!

[Hashim]

sportz_kruzer your reply gave me a real shock! At just 4519km can valve burn? Yes the engine do overheat and I can feel the heat on my foot as well as my very sensitive nose smell burning something on the right side of engine.

However after recent service the problem of engine shutting is gone, I am still not happy with the engine response as it jerks sometimes when opening throttle to speed up from low speed say 30kmph in 3rd or 4th gear.

I don't get time to go service center again and again for complaining and I have started to live with this not so smooth engine problem.

However if I get a good solution which will solve my problem I am ready to part a whole day at service center to get this fixed. I'll talk about this to mechanic to does service of my bike at the dealer and tell him to check valves whenever I pass by that road.

Basically I never checked my bike mileage and after owning a car when I use bike I feel like I am having a free ride ) never told service center to tune it for mileage but who knows they did that or not.

[sportz_kruzer]

seems a lean setting to me. can you tell me how many turns is the air/fuel mixture screw set to? Factory setting is generally 2.5 to 3 turns anticlockwise from fully closed position. I am comfortable with 4-5 turns as it gives a balance of power and mileage...but thats for my pulsar.

Or rather have a look at the spark plug. If its light brown in color that means the bike is running very lean and you need to richen the mixture.