03 RX1 backfiring

[bluecj]

y 03 RX1 is backfiring at low and mid throttle for the last 2 years. Still has good power and idles fine. Cleaned the carbs myself and had them cleaned at a repair shop and it did no good. Did a leakdown test. Cylinder 1 only 5% leak, Cylinder 2 had 100% leak and could hear air in the exhaust and airbox, Cylinder 3 had 75% leak and could hear air in exhaust, airbox, and cylinder #2, Cylinder 4 had 50% leak. Do you think this is valves? headgasket? cam? Stock engine, aftermarket muffler, 2500 miles.

 

[Bigfish]

Only 2500 miles!!! Yikes!

What is your oil consumption like? If your not using a lot then I would think valves maybe your issue. But the only way to tell is to open it up!

 

[bluecj]

I rode it 1000 miles last season and it burnt no oil or coolant.

 

[brian73]

Did you rotate motor in between each cyclinder to make sure each one is one is at top dead center? If yes I would have to think the timming jumped one tooth. Otherwise if your not burning oil, it has to be in the valves. Eather way it more than likely has to get opened up. Please keep is informed on what you find.

 

[dexter]

y 03 RX1 is backfiring at low and mid throttle for the last 2 years. Still has good power and idles fine. Cleaned the carbs myself and had them cleaned at a repair shop and it did no good. Did a leakdown test. Cylinder 1 only 5% leak, Cylinder 2 had 100% leak and could hear air in the exhaust and airbox, Cylinder 3 had 75% leak and could hear air in exhaust, airbox, and cylinder #2, Cylinder 4 had 50% leak. Do you think this is valves? headgasket? cam? Stock engine, aftermarket muffler, 2500 miles.

bluecj... i just had my valves done at 12k miles and my readings were way worse, but I could hear what you did. they were like 30% on almost all of them. mine just wouldnt start easy at all... thought it was rings, but shop told me not likely and did the leakdown. yami only states 8% leak is acceptable I think they told me. they also said they have done valves on 2010 sleds with like 2k miles... just varies on how you ride and carbon build up. after the job the sled rides better than new.. throttle feels better than my apex did. hope this helps..