Venture lite stalls at idle

[wacnstac]

I've noticed by venture lite wanting to stall at idle for some time. I tweaked the idle speed to set it at 1700 rpm a while back as mine was idling at a lower speed. Lately, usually after a long ride when the sled is good and hot it wants to stall immediately upon stopping (thumb off throttle). After a stall it is hard to restart. Usually have to hit the throttle as soon as you think it might start.

Any ideas on this one? I'm sort of at a loss. No codes or lamps. Opened up the air box to make sure there wasn't a mice nest in there. Also the high end power seems to be fine.

 

[Mooseman]

I've noticed mine is sometimes hard to start if it's good and hot. No problem with idle though. I was thinking of putting it in diagnostic mode and playing with the fuel settings, possibly enriching it a little, because I have noticed an off-idle stumble when hitting the throttle.

 

[wacnstac]

Well I really am not experiencing an off idle stumble. The problem with those fuel settings is that they apply throughout the entire rpm range. I'm wondering if my valves need adjustment.

 

[BACK COUNTRY YAMAHA]

check your throttle free play if not in spec will cause this, the tps is not in the correct position in relation to the throttle switch at your thumb, thus no fuel at idle or not enough to maintain idle! cheers!

 

[wacnstac]

But would that cause the loss of idle only when hot?

 

[BACK COUNTRY YAMAHA]

can't say for sure when cold but when warmed up it will, had this on my atv, it just started to act up and realized the lock nut for the cable adjuster backed off and as soon as let off the throttle bike would die, also if your tps goes out of adjustment it will either give too much fuel or not enough! giving you the same result! The tps basically feeds the ecu the proper reading for operation! ! I know it's a pain to do on the lite, but if your cable hasn't been adjusted it's the first thing I would look at! cheers!

 

[wacnstac]

can't say for sure when cold but when warmed up it will, had this on my atv, it just started to act up and realized the lock nut for the cable adjuster backed off and as soon as let off the throttle bike would die, also if your tps goes out of adjustment it will either give too much fuel or not enough! giving you the same result! The tps basically feeds the ecu the proper reading for operation! ! I know it's a pain to do on the lite, but if your cable hasn't been adjusted it's the first thing I would look at! cheers!

Sounds like a good suggestion. I hope that is it. Will give it a shot.

 

[wacnstac]

can't say for sure when cold but when warmed up it will, had this on my atv, it just started to act up and realized the lock nut for the cable adjuster backed off and as soon as let off the throttle bike would die, also if your tps goes out of adjustment it will either give too much fuel or not enough! giving you the same result! The tps basically feeds the ecu the proper reading for operation! ! I know it's a pain to do on the lite, but if your cable hasn't been adjusted it's the first thing I would look at! cheers!

The more I think about it, the more I think you are right. I very recently adjusted the idle speed as it was too low. Should have read the service manual on this, as it says when adjusting the idle speed you must check the throttle free play afterwards which I did not do. Might work this in with my next oil change as I need to take the air box off to do the job.

 

[wacnstac]

Finally getting back to this as I'm getting my sled ready for winter. I'm running a little late this year. At first glance my throttle seems to have 0 end play. Manual says it should be a couple mm. Could too little end play cause this?

 

[Mooseman]

Certainly sounds like it. Could also check that the TPS is properly adjusted.

 

[BACK COUNTRY YAMAHA]

I believe the manual gives a min and max adjustment, I would definitely keep it on the min clearance. also there is a synchronization of the throttle bodies, with the airbox off ensure both butterflies are opening the same time when you open the throttle and that they have the same gap when closed. cheers!

 

[wacnstac]

Certainly sounds like it. Could also check that the TPS is properly adjusted.

I stand corrected. I was measuring free play wrong. My free play looks to be about 4+mm. I will reduce to 2mm. What is the TPS adjustment procedure? I see some talk about putting the sled into diagnostic mode and checking it. Is that what you are talking about?

 

[BACK COUNTRY YAMAHA]

not sure if the tps voltages are in the diagnostic mode or not, the only time I had to adjust a tps was on a side by side where the idle was all over the place, most of time low to a point it would load up and stall . Had to make up a harness to go in line between the tps and the connector then I could turn on the key and get the voltage measurement if it was off from spec then I just slacken the two tamperproof bolts and adjust until voltages came in spec and tightened. Never had any more issues with idle after that, bike worked flawless after that! cheers!

 

[Mooseman]

This should help. No need to go into diagnostic mode.

 

[wacnstac]

This should help. No need to go into diagnostic mode.

That's a good thought to do that while I have the air box off. Might have to jumper to the harness for the second test so I can get meter in there while it is connected to harness. They don't say if the second step should be done with the key on or what the throttle position should be.