Throttle Needed on Start Up

[ThatOneGuy'sBrother]

Jon with no H? Lol. If so your parents were good peoples. !! Lol. I’m heading to the UP Wednesday. Probably be a ice fishing trip though. Eh? Lol

Yup Jon with no H.

Dont think there will be much left to ride on shortly. Sun has a lot of power this time of year!

 

[0degC]

Just did a cold start on my SW
-20c/-4f
closed loop 240SS selected
When the O2 sensor activated AFR was 11.5 and stayed 11.5 right through the cold temp warning with a steady smooth idle at 1800rpm.
When the sled was fully warmed up, @ 165f, idle is rock steady at 1500rpm with a 12.1 : 1 AFR

Yes that’s about what I see. Mine needs a bit of Throttle at times cold starting. I would have thought would start and idle leaner... those are pretty much WOT safe numbers. Thanks

 

[ThatOneGuy'sBrother]

Got the sled back from the dealer there was nothing they could do on the idle issue. It was running fine for them. Just have to live with it.

 

[jonlafon1]

Got the sled back from the dealer there was nothing they could do on the idle issue. It was running fine for them. Just have to live with it.

That's not good. If I had to guess the valves need adjustment. Most dealers don't want to do this, or don't have the knowledge to check them IMO..
I don't know with 100% certainty its the valves, but something is wrong! NO WAY motor should need throttle when starting or idling!
Sorry to here. Running fine for them! Heard that before,.. Shoot a video of your issues with this sled and show them.. Video does not lie!

 

[Sledroll]

That's not good. If I had to guess the valves need adjustment. Most dealers don't want to do this, or don't have the knowledge to check them IMO..
I don't know with 100% certainty its the valves, but its something that's wrong! NO WAY motor should need throttle when starting or idling!
Sorry to here. Running fine for them! Heard that before,.. Shoot a video of your issues with this sled and show them.. Video does not lie!

That can"t be acceptable .
Is it doing it still for you , since you got it back ?
if so can you take it to another dealer ?

 

[ThatOneGuy'sBrother]

That can"t be acceptable .
Is it doing it still for you , since you got it back ?
if so can you take it to another dealer ?

Has not done it for the dealer. So their defense its hard to fix an intermittent issue that they can not duplicate.

 

[jonlafon1]

Has not done it for the dealer. So their defense its hard to fix an intermittent issue that they can not duplicate.

Tell them you want the valves checked, and WITHIN spec if they are not! Only issue will be if they check them and they are within spec, they will charge you probably.. Depends on your relationship with dealer and how good a dealer they are.

OR wait until next year and on the cold morning when it acts up shoot a video! Send it to them..

 

[Sledroll]

Tell them you want the valves checked, and WITHIN spec if they are not! Only issue will be if they check them and they are within spec, they will charge you probably.. Depends on your relationship with dealer and how good a dealer they are.

OR wait until next year and on the cold morning when it acts up shoot a video! Send it to them..

No chance of a cold morning in the next week or so , that you can test it out .
My dealer is not perfect , but when I was having an issue with my SW not going into reverse , and they could not replicate it , they went ahead and replaced the bearing , gear , and fork pads , as that would be the cause , and they believed that it did happen to me , to the point that my last ride of that year I was advised not to use reverse, as it might leave me with no forward either .
I don't know what the probable causes could be for needing to add throttle to start ? air leak ?

 

[jonlafon1]

No chance of a cold morning in the next week or so , that you can test it out .
My dealer is not perfect , but when I was having an issue with my SW not going into reverse , and they could not replicate it , they went ahead and replaced the bearing , gear , and fork pads , as that would be the cause , and they believed that it did happen to me , to the point that my last ride of that year I was advised not to use reverse, as it might leave me with no forward either .
I don't know what the probable causes could be for needing to add throttle to start ? air leak ?

Few possibilities, but IMO a code would show on most.. If the valves are to tight/not within spec it will start hard idle like #*$&@ and run on 2 cylinders.. Especially when COLD.. I in no way saying its that for sure.. Just a guess.

 

[Turboflash]

Without seeing sled, to me it sounds like a TPMS problem?
Slightly opening throttle to start is doing what? Increasing TPMS voltage to ECU. Perhaps base idle is TPMS voltage is so low it's either out of range or so low the ECU has the injector pulse so low it won't start?
Is TPMS working correctly? Only electrical testing could find out.
Still could also be MAP problem.

 

[ThatOneGuy'sBrother]

Without seeing sled, to me it sounds like a TPMS problem?
Slightly opening throttle to start is doing what? Increasing TPMS voltage to ECU. Perhaps base idle is TPMS voltage is so low it's either out of range or so low the ECU has the injector pulse so low it won't start?
Is TPMS working correctly? Only electrical testing could find out.
Still could also be MAP problem.

When it is acting up it will run rough. Or only stumble on start up. When it starts and runs but is acting up it sounds like it is only running on 2 cylinders.

One time it would just stumble and die every time I tried to start it. I attempted to start it like this for 10 minutes or so. Then i held the throttle open. It took off out of the trailer. Thats when I realized it took throttle to get it started. It would die as soon as you let off. So i kept the rpms below clutch engagement till it was plenty warm. It would still die if you let off the throttle. While holding the throttle just below clutch engagement it ran smooth. If you let go of the throttle it would stumble and die. We rode it for about 15 minutes like this and then it came out of it and ran fine for the rest of the day. Any other time it wouldn't start i knew to hold the throttle open.

I will have to take a video when it acts up again.

 

[NYTurbo]

I'd be checking valves, seen many with similar symptoms where they have spit a shim after a blown belt. But they don't usually rectify themselves like yours is doing.

 

[jonlafon1]

Its almost exactly like a Viper I have been riding with for 4 years.. Not as bad as you describe, but similar.. We saw this #*$&@ idling and 2 cylinders running ONLY when it was cold out.. Like below zero at night and starting in the morning.. 5 degrees or warmer at night it was fine.. He ended up paying to have the valves adjusted and it was better not perfect but better. We saw times where it would not even start at all.. And times where you HAD to hold throttle as your saying

 

[jonlafon1]

I would like to add the sled was under Warranty and Yamaha did not cover it.. Well whatever happened with him and the dealer I guess,, He didn't care he just wanted a sled that started and idled properly. He ordered a Winder for 2022

 

[MrSled]

When it is acting up it will run rough. Or only stumble on start up. When it starts and runs but is acting up it sounds like it is only running on 2 cylinders.

One time it would just stumble and die every time I tried to start it. I attempted to start it like this for 10 minutes or so. Then i held the throttle open. It took off out of the trailer. Thats when I realized it took throttle to get it started. It would die as soon as you let off. So i kept the rpms below clutch engagement till it was plenty warm. It would still die if you let off the throttle. While holding the throttle just below clutch engagement it ran smooth. If you let go of the throttle it would stumble and die. We rode it for about 15 minutes like this and then it came out of it and ran fine for the rest of the day. Any other time it wouldn't start i knew to hold the throttle open.

I will have to take a video when it acts up again.

I had this happen twice on my wives winder, exactly as you described. Pull the sled in the heated shop for a week to give it a good thaw and problem has not came back. This started after I thought it would be a good idea to warm up all the sleds in my enclosed trailer and then got busy never opened the trailer to let out the moisture. I think it was moisture issue and something was sticking.. at this point that all I have to go by.