So i guess I should share this because it could be seen as a resource for some and a cautionary tale for others.

I bought a 1990 bayou 300 a year and a half ago. When i bought it it ran poorly the engine sounded like a tap class going on the start button didnt work, there was no power under throttle and it was ugly as sin. Sounds like a fun project right?

Well i brought it home found out it was missing the air filter assy completely. So i fabricated a new one out of pvc. I also removed the wiring harness to look for issues on my bench.

After going through the harness and repairing a bunch of grounds and reinstalling on the bike I found the start solenoid wasnt working. I dismantled the solenoid and found that the magnet wire directly under the cover had broken. After reassembling the solenoid the starter began working.

However the bike didnt want to start now. When it was cold out the bike wouldn't run for anything but when things warmed up it would run. After poking around I found the pulse coil was intermittent. I orderd a new one and got it installed and now the bike starts more predictably. I also replaced the rectifier and connector as the old connector was burnt.

After that I wound up taking the head off with a friend with more atv experience than myself. We adjusted the valves and inspected the cylinder reset timing and tried to start it only to find it wouldnt start. We loaded it into my truck and I brought it home. When i got back I had the idea to release the timing tensioner and see what happened and gave it a start suddenly the bike ran great. At this time there was no issue with the throttle bogging. I jumped on and put it in first only to have the bike clunk like it had suddenly had the brakes applied to the cylinder. I tried pushing the bike forward and backwards in gear only to find the rear wheels locked. I get back on and put the bike back into neutral it starts right up and runs great but when I try giving it gas, in first, it stops instantly.

I decide to start it in second gear and see if it will move under its own power and it moves like it should. Which tells me that first gear is stuck, I'm moving in second gear alright( what Im about to tell you isnt advise I knew the risks involved and made my own decision.) I give it some gas to get the bike moving and then drop the bike into first and the bike skids for a few feet and then starts moving under power again.

I do a couple laps around the field running through the paces to see if it was a good investment it ran well... until it didnt. Suddenly the bogging is back and it wont move under power again. I spoke with my friends who know smaller engines better than me. All of them point me to the carb and fuel tank.

I take their word drain and clean my tank, then clean the carb(both needed a good cleaning). Still no joy, so I cleaned the carb again. Then figuring the passages were clogged or the choke diaphram was torn i decided to get a new carb, and jets. I spent a week testing jets in the new carb until i could finally get 1/4 throttle before the bog and move under power, a little.

At this point winter set in and it was too cold to work on it, its too cold to work on where i store it. But I've had plenty of time to revisit this issue in my head. My next course of action is going to be to reset the timing chain and if i get it running right then lock that damn tensioner down.(I forgot to do that when i was riding it and pretty sure thats the source of bogging.)

If everything works after that Ill build it a new front basket get some lights on it and get started on the next project bike. A 220 bayou that was obviously pulled apart for parts.