67.25 mm bore - wiseco piston - stock bottom end - stock exhaust

Mar 3, 2024
I bought a 2000 blaster from a guy for $375 a couple weeks ago. The engine wouldn't turn over and I hoped it was a seized piston. After I got home I noticed the oil pump line to the carb was not connected and there was no cap on the nipple on the carb. Long story short the piston had pitting on the face and the skirting on the intake side broke off and into the crankcase. So I am replacing bearings, seals, crank (the crank connecting rod bearing was shot), and the clutch. I'm running stock exhaust. The crank should be here tomorrow and I want to order the correct jets so I can get this this running by the weekend. Any help you guys can offer would be awesome. P.S. I am at 841ft elevation


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If you are running the stock carb, you shouldn't really need to change jetting for a simple bored over top end.
Oh really! That's great. Does the clymer manual have this kind of info or is there somewhere I can go to find out things like this so I don't bug the experts with trivial stuff like this? I am new to working on ATVs and engine rebuilding in general. If Michael Sabo and 2vintage haven't said it explicitly than I probably don't know it
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Service manuals like Clymer typically only cover the procedures and specs of doing these types of repair and don't go into jetting and other modifications, although it may have a section on basic carb tuning which is generally good info. It's been awhile since I've cracked open a Clymer so I'm sort of taking a bit of a guess here.

I should add that while it's very unlikely a jetting change will be necessary on a stock cylinder that's just been bored over with all other parts stock on the quad, you should still verify jetting is safe. I'd be very surprised if changes are found to be necessary, especially since an ATV of that vintage didn't have to contend with EPA emissions regs like they do nowadays and were typically jetted to be very safely on the rich side of things from the factory. They wanted the ensure a new ATV could be operated in pretty much any elevation and weather condition without the risk of burning down due to a lean condition. Helped to keep warranty claims in check. Just be sure the carb is in good condition and thoroughly clean for proper fuel delivery.

And don't feel bad about asking questions. We all started at step 1 at some point. People like me who have been messing around with things like this for over 30 years didn't have the Internet to tap into for info and are glad to help.