spiralsun1

I am experiencing technical difficulties. See if you can figure out what this is, I cant! OK, I put in the larger jets on my 20mm carb on my crf70 88cc with race head (see my earlier post)-- it did not help. It runs fine at idle -- perfectly smooth. Then it runs fine with the throttle just barely on. Anything beyond that and it's like it just completely loses power the more throttle you apply with only little blips of power here and there, it just breaks up and runs really rough bogging down horribly occaisionally punctuated with very loud backfires. I changed the jets up, pilot jet, main jet, and dropped the needle clip all the way down -- still runs super super bad at anything above idle or barely throttled on. it sounds like it is running out of gas -- it just completely loses power at times then hits a tiny bit, but slows almost to a crawl wide open with huge backfires. not good. Any ideas?

Help please if you can, I'm really at a loss. Could it be a failure of spark advance? Honda said the valve adjustment and timing are fine. I thought maybe I put the cam in wrong, but how could it run perfect at idle if so? Very strange. I know that from idle to 1/4 throttle is the pilot jet, so it does seem like a fuel or jet issue, but I put in a 92 main and 38 pilot and it did not help. I dropped the needle clip all the way down too, no effect.

Do I need a MUCH larger main jet? I heard someone here drilled out a jet to 110....? I just don't know. Someday I really want to ride this bike. It has been a year.