Runs great until fully warm, looses power backfires and dies

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NEWFISHER
Posts: 315
Joined: Mon Nov 09, 2015 10:52 am
Location: Oregon--NorthWet

Re: Runs great until fully warm, looses power backfires and

Post by NEWFISHER »

Update on the backfiring and dieing:

Timing checked-off just a degee
Valves adusted-most slightly tighter than .20mm
Carbs rebuilt- forward carb body loose.
New muffler installed, previous leaking joints omitted or repaired in exhaust.

I believe the culprit was the carb. I had previously pulled both and lock tighted the 4 screws from the bases but when I took that rolling backwards solid hit at 10mph and stopped abruptly, I believe the weight of the carb/air cleaner intake pulled the forward carb back enough that the attatchment hold down bolt didnt keep the assembly solid and it jerked the carb body. We found it loose again on the rebuild, looser than previously and the threads totally stripped. Tine or nut serts into the carb body and a carefull overhaul of each was the biggest change. Heat and the expansion of the bases causing a greater lean issue after 10 min is my only idea?

Drove it for 2 hrs tonight, stopping for hot soak, traffic, stop and go and some freeway pulls and no issues.

Thanks to all for the suggestions and direction. Seems to be a runner again and back to daily driving. I can now get back onto my front lift bushing project ;)
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