2021 Sidewinder Hard Starting

[Rossv123]

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

 

[Turboflash]

How's it run once it's running? Normal?

 

[Motorhead]

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]

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]

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!

 

[1nc 2000]

Low battery voltage it will crank slower.

 

[ThatOneGuy'sBrother]

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]

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]

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!