I started sled this afternoon. Have not checked the plugs yet at work now. But i fired up just fine then i turn choke off and reved it up to 4000 and held it there then brought it down to idle and i made a loud crackle pop sound when rev back up and started to back fire. I have been starting it up and shutting off alot lately? Do you think it was just plugs or too much fuel. Or could it possible to crank? I sounded like it was running on all three but the second time i reved it it seemed to have a little less power when i began to backfire. it also has gotten a little colder out lately. I guess i also didn't let it warm up really just went straight to 4000 rev.
It was engaging normal too. I just had to get to work so now im sitting here nervous?
It almost sounded a few times like not a backfire but a popping sound when i first noticed it backfiring.
It was engaging normal too. I just had to get to work so now im sitting here nervous?
It almost sounded a few times like not a backfire but a popping sound when i first noticed it backfiring.
first thing i would check would be plugs, pull them carbs and give them a good cleaning before the snow fly's 
One other thing to check would be the T.O.R.S. Be sure the throttle cable isnt binding and that the throttle lever is moving freely at the pivot pin. The T.O.R.S. will cause the motor to rev funny and misfire(or atleast sound like it is)
Otherwise, do as dhoward suggests. Most likely a fouled plug or two.
Otherwise, do as dhoward suggests. Most likely a fouled plug or two.
Just cleaned the carbs about a 2 months ago. Probably started it 20 times sence or less? this is the first time i have had a problem like this. Hopfully there is no white on the plugs when i change them out... Im hoping it was just a litte to much fuel and a bad plug.
super1c
Super Moderator
First thing i would do would be to clean the carbs again. I now you said you cleaned them 2 mo ago but you have started it since then and let it sit. Second thing you need to do or should i say not do is start it again. Starting a sled like that is the worst thing you can do to a 2 stroke. You would be better off not doing anything to it. If it were mine i would start it again and fog the engine. Then clean the carbs and put it away till the snow flies. I know its hard but your engine will thank you. I never start mine till im sure it will be rode. Im sure you did no damage to your engine but its probably dirty again. Our gas sucks. Starting like that without a long heating period will result in moisture build up and that will hurt your engine. My 2 cents. CCC
Yep. I've actually seen the water stains in the bottom end of 2-stroke engines belonging to people that thought it was a good idea to start them up a bunch of times during the off season. Not cool. It's a real good way to make sure your crankbearings get good and rusty.
Netefrog said:
X3 - in fact you'll find the same cautions about summer storage in your owner's guide. Fog it and forget it.
I'm sure you've loaded up a plug or two so I'd suggest running it on a stand a good 20 minutes with a couple WOTs to help clean things out (get the HXs hot). Drain the fuel into your car/truck, fog it and pull the carbs for cleaning.
Add fresh fuel and spark plugs before loading it on the trailer... hit the lake with less worry whether your fuel is up to snuff or not.
With different regulations from state to state regarding ethanol and winter/summer RVP I think the above is good practice regardless of where you live.
i switched plugs ran it and all is good. Just too much fuel....
bluemonster1
LIFE MEMBER ONLY ONCE!!!
clean them carbs.Been sitting to long,and with the fuel you guys have now..sitting for 2 weeks,gas should be drained and re filled fresh.If not..you'll get a great big KABOOM!!!!!!
what will like 100 octane do for me if i go to the airport and get it? If i jet to this ? any performance diff or just possibly cleaner everything? Stock Motor
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bojisrx said:
It will do no good for your stock motor. You'll probobly loose performance.
super1c
Super Moderator
Just run what it says in the owners manual for stock like frog said. I think but cant remember for sure that 87 is all thats recomended for the viper. With todays gas I alway run at least 91 in all my sleds moded or stock. CCC
madzx2
Member
bojisrx said:
i ran a mix of race gas and 92 premium. it figured out to be about 96-97 octane. this was in my ported srx with head work done to it and my speeds slowed down a ton.