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Arizona last won the day on April 11

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About Arizona

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  • Location San Antonio, TX, USA

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  1. no coolant, air cooled unless im missing something. Cant seem to find a cylinder for sale, Only one I found was 400 plus. The cyl wall is definitely gouged. The bearing looked ok but would replace if repairing.
  2. Trying to figure motor size, says nothing on plastics, or the title, only numbers are EC25PFX 01 Which are on the cylinder. The vin code is 4XAAG25C312459874 Tried vin search but still doesn't show motor size.
  3. Ok, so not doing anything today so figured I would look inside. Finally get the head off and actually looks good. Was expecting an exploded piston. Got the cylinder off and that's when I saw the damage. Hopefully it can be bored instead of replaced. Do you thing it was starved of 2 stroke oil? The previous owner had removed the carb and tried to fix it and had problems after that. I did see the oil line was connected to the carb and the oil tank is full so I am guessing. The damage looks like it had no oil but what do I know. Any thoughts? Az
  4. was going to adjust the clutch but lucky me the 300 it looks like you have to take off the case to do that. There are 2 covers on the clutch side, took both off nothing there, looks like adjustments are internal. May put it off until I finish the Polaris. Az
  5. Ok, so its been a while on this bayou 300. It runs great but has a tapping noise from the motor. Gets worse as it warms up. Runs smooth, but that noise is pretty loud, I know its hard to identify motor noises but thinking may need piston. Gonna eventually pull it apart after done with my other project. Not sure what rod bearings sound like on a atv but to me it sounds like piston or wristpin. What you think. You tube video here--------
  6. So few months ago I acquired a 01 Explorer 4x4 (think its a 350 but not sure) Anyway the owner said it started reving very high, shut the key off and still kept running until finally he shut off fuel and it finally died. During the run away he said the exhaust got red hot and has melted plastics to prove it. Said some thing flew out the tail pipe, I kinda figured it was the top of the piston. Anyway finally got around to looking at it (have a lot of other projects in the works) and checked the compression, Shows about 40 psi. Can hear air coming out the carb while rotating the motor over. Gonna pull it apart eventually, don't hear any noises or binding in the stroke, You think the piston came apart? any horror stories of these and is it worth my effort and money? Don't really have any money in it yet. Thoughts? Az
  7. Well im looking into a used oem carb. The online engine builder says he has a few and should call me back. also found 1 on ebay but looks pretty rough. Ign. coil was putting out about 28kv I sure find the weird ones! Az
  8. talked to an atv engine builder and he said you will get different compression readings between no throttle and full throttle. Should be checked at full throttle. I checked the online manual and it says check at wot
  9. I agree weird readings. But they are repeatable. Just depends if throttle is open or not. Would think cam problems would be constant. I cant think of anything that would make them change due to throttle angle. Im stumped. Any Yamaha motor builders out there that have ideas? On a second note, after screwing with the second carb I got it to go quite a bit faster but still not right. I can floor it in neutral and it wont redline. Just revs about half of what it should be. Pretty odd as it idles pretty smooth and starts pretty easy. Hoping for some knowledge on the motor Az
  10. Yes the compression changes every time I either open or close the throttle. Never heard of the readings changing with throttle angle. It will read 125 as long as throttle is opened. If not it reads about 85psi. The motor runs super smooth at idle and doesn't smoke. Any ideas what I should do with it or just leave it alone? Now second thing. I do not have the oem carb. Should I try the jet kit on the new Chinese carb? or wasting my money? Az
  11. Well was going to tear it down today but double checked a few things rechecked compression, right at 85psi then rechecked compression with throttle wide open and I get 125 psi. Double checked and confirmed with throttle open 125 psi. so I assume the motor is not the issue. Still looking at the carb as it feels like a carb issue. Similar to problems with the Kaw bayou 300 I had. So gonna set the valves before I put it together, Since I don't have original carb and have tried 2 Chinese carbs, should I try a jet kit and install in this carb? If so what ones do you have the most luck as far as accuracy with? Might also see if ign. coil is putting out enough volts, I am assuming it should at least put out 20kv Any other ideas? Thanks Az
  12. usually a good smack to the fuel bowl with a screwdriver handle will bust it loose.
  13. So my latest find is a Moto 4 250. Looked in good shape, started right up but would backfire and die upon acceleration but you could get it to go if you were good with the throttle. I figured it was the carb. was a brand new Chinese carb, he didn't have original. I took it apart and cleaned it, only thing I found was some debris in main jet and the main adjustment on bottom was at 41 turns. Cleaned it out and set at 2 turns, re installed. Starts up, runs better actually drove it but seems really sluggish, once I hit 3rd gear could barely pull it. Rechecked everything, even ordered a new carb as I had this problem with another atv but still same problem. Now I pull it apart and decided to check compression, I show only 85 psi. I checked valve adjustment (after aligning up cam gear to mark on case). to make sure not too tight still right at 85 psi. I assume I need to pull the head and look at the valves, Any ideas I am missing something? motor does not smoke but is super sluggish. The specs I find are off the downloaded manual of a 94 but figure should be the same. It states compression standard is 128 and Minimum is 114 and Max is 142 Any other Ideas before I tear it down? Thanks in advance Az
  14. Nice of you to let the kid have it. Nice work, like the green and the air filter color matches as well.
  15. Well decided to do the drive yesterday after work. Looked at the Yam 250 and in pretty good condition. Starts right up, new tires, all lights work etc. Just needs carb redone and some detailing. Tried to get Willie and the boys to help load it up lol Az

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