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2021 Sidewinder Hard Starting

Rossv123

Newbie
Joined
Dec 15, 2020
Messages
14
Age
21
Location
Michigan
Country
USA
Snowmobile
2018 Thundercat
If installing new plugs, as also mentioned in previous post, you’ll have to lessen the stock plug electrode gap from .030” to .020”!

Have had mine changed out in years past by dealer troubleshooting Warranty cold start problems, so I never bothered to do plugs on my 17 Winder.

This season I did my own and the ones that came out of my 998 had the stock gap, and the new ones bought at parts store were also .030”. So this will be my first year trying the .020” gap on my tuned Winder.
I put in new plugs gapped them and put in new fuel and let it run through it and it still starts hard any other ideas
 

Motorhead

TY 4 Stroke God
Joined
Apr 20, 2003
Messages
2,030
Location
Augusta, Maine
Country
USA
Snowmobile
2017 SW LTX-LE
LOCATION
Augusta ME
I put in new plugs gapped them and put in new fuel and let it run through it and it still starts hard any other ideas
No I don’t, sorry.
Even though I had similar problems with mine, it was on a 5 year warranty plan, so my Really Good dealer fixed it, and the amount of items changed out had the service manager pulling out his hair. He showed me the list, and it took them many days, whereas my problem was cold starts, so they needed cold weather to duplicate the symptoms.

On frosty cold mornings it would not start without 1/4 throttle, it would just fire and stall, and when you did the 1/4 throttle thing, it would stall right away after letting off the throttle, really run fat. This would happen for15-20 minutes when it first surfaced. But warm starts and warm weather cold starts we’re not a problem.

I do know that they changed out my fuel regulator twice, once for the cold start problem and once for mileage issue I was experiencing. But whereas yours is hard start always, it’s symptoms are a bit different!
 

jonlafon1

Lifetime Member
Joined
Aug 18, 2014
Messages
3,924
Age
48
Location
Mount Morris, WI. Chaney Lake, Upper MI eh!
Country
USA
Snowmobile
2022 Sidewinder LTX_SE

2024 Catalyst

2017 Sidewinder LTX-SE. 11750 miles (SOLD)
No I don’t, sorry.
Even though I had similar problems with mine, it was on a 5 year warranty plan, so my Really Good dealer fixed it, and the amount of items changed out had the service manager pulling out his hair. He showed me the list, and it took them many days, whereas my problem was cold starts, so they needed cold weather to duplicate the symptoms.

On frosty cold mornings it would not start without 1/4 throttle, it would just fire and stall, and when you did the 1/4 throttle thing, it would stall right away after letting off the throttle, really run fat. This would happen for15-20 minutes when it first surfaced. But warm starts and warm weather cold starts we’re not a problem.

I do know that they changed out my fuel regulator twice, once for the cold start problem and once for mileage issue I was experiencing. But whereas yours is hard start always, it’s symptoms are a bit different!
Any chance this dealer adjusted the valves on your machine? I know for a fact the Vipers had issues with valves and COLD mornings. Hard starts, running on 2 cylinders instead of three. I realize we’re talking two different motors here but the symptoms sound a lot alike. I can attest to these symptoms first hand as I watched it on a friends VIPER often. Just throwing out ideas.
 

Motorhead

TY 4 Stroke God
Joined
Apr 20, 2003
Messages
2,030
Location
Augusta, Maine
Country
USA
Snowmobile
2017 SW LTX-LE
LOCATION
Augusta ME
Any chance this dealer adjusted the valves on your machine? I know for a fact the Vipers had issues with valves and COLD mornings. Hard starts, running on 2 cylinders instead of three. I realize we’re talking two different motors here but the symptoms sound a lot alike. I can attest to these symptoms first hand as I watched it on a friends VIPER often. Just throwing out ideas.
I do not remember anything about valve adjustment when the service manager let me see his work order warranty claim!
It was stuff like fuel regulator, tps, plugs, etc! My receipt just explained why it went in, so no parts replaced breakdown! Didn’t cost me a penny just 3 trips of having to use the throttle to cold start and keep it running for 15 minutes or more before it came out of it! I do know they were communicating with Yamaha tech whereas They said my sled was the only one they knew of that was happening to!
 
Joined
Oct 12, 2014
Messages
104
Age
38
Location
Monroe County Norwalk WI
Country
USA
Snowmobile
2020 Sidewinder LTX GT 2015 Apex XTX
No I don’t, sorry.
Even though I had similar problems with mine, it was on a 5 year warranty plan, so my Really Good dealer fixed it, and the amount of items changed out had the service manager pulling out his hair. He showed me the list, and it took them many days, whereas my problem was cold starts, so they needed cold weather to duplicate the symptoms.

On frosty cold mornings it would not start without 1/4 throttle, it would just fire and stall, and when you did the 1/4 throttle thing, it would stall right away after letting off the throttle, really run fat. This would happen for15-20 minutes when it first surfaced. But warm starts and warm weather cold starts we’re not a problem.

I do know that they changed out my fuel regulator twice, once for the cold start problem and once for mileage issue I was experiencing. But whereas yours is hard start always, it’s symptoms are a bit different!
My bone stock 2020 ltx gt is doing the exact same thing. It will only start with 1/4 throttle and will die when you let off the throttle. It was 35 out today and it still did it. If anyone knows what can take care of this issue it would be greatly appreciated. Had it at the dealer for this already. There was nothing they could do.
 

Turboflash

VIP Member
Joined
Mar 18, 2019
Messages
2,106
Location
Southern MN
Country
USA
Snowmobile
'17 ZR9000 Ltd. PEFI Stg 3R
My bone stock 2020 ltx gt is doing the exact same thing. It will only start with 1/4 throttle and will die when you let off the throttle. It was 35 out today and it still did it. If anyone knows what can take care of this issue it would be greatly appreciated. Had it at the dealer for this already. There was nothing they could do.
I don't have any ideas or advice but I sure would like to get a sled like this in my shop and see if I could figure it out. I really enjoy a challenge.
As we all know, internal combustion engines need air, fuel, and ignition. Likely air is not the problem (LOL we're all breathing it). Doubtful fuel is issue on stock sled unless for some reason, the injectors are plugged up due some really dirty gas. Could happen. So, that leaves ignition which is my best guess. Might want to put a charger on battery while starting it so see if anything changes. Measure battery/charging system voltage. Are plugs fouled?
 

Motorhead

TY 4 Stroke God
Joined
Apr 20, 2003
Messages
2,030
Location
Augusta, Maine
Country
USA
Snowmobile
2017 SW LTX-LE
LOCATION
Augusta ME
My bone stock 2020 ltx gt is doing the exact same thing. It will only start with 1/4 throttle and will die when you let off the throttle. It was 35 out today and it still did it. If anyone knows what can take care of this issue it would be greatly appreciated. Had it at the dealer for this already. There was nothing they could do.
Wish I knew what the repair was to mine, but I don’t, and not too sure that they knew because of the lengthy list of things they swapped out and checked!

All I know was something did not like the cold, and made it run crazy fat until way after the engine got fully warm!

It took them weeks to diagnose once it got cold enough to duplicate it’s symptoms!

When above freezing, it started. OK!!

Good luck and hope it’s under warranty!
 


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