Frank Angerano

Have you looked on eBay for a used one ? I’ve picked up an oem carb before from eBay in good shape put a rebuild kit in it and for $100 I had a very good oem carb. im assuming yours is beyond repair or the bike cane without one ?

Very good. Should be a sold engine after that. Good luck and keep us posted.

You are missing something, did you wire brush the top of the piston and the head for carbon build up to make sure there aren’t any pinholes or cracks? I would also check the head where the gasket sits to make sure it’s not warped. And lastly the rings could be bad even though they look ok. I would think it’s just a piston and ring replacement job. There could be a hairline crack in the cylinder jug or head but that would probably have shown up with a dark spot or hearing air coming from it. I would put a new gasket kit and piston and rings and see where you are at. Ive heard of the 50cc engines losing compression from the crank case bearing seals but not on the 80.

Welcome to Quadcrazy. From your description it sounds like you heard a noise and then it shut off? Is the bike in neutral ? It’s possable that the engine is seized up. I would take the spark plug out and try to pull start it to see if the engine turns over. Then drain the oil if there is any oil in the engine and see if any metal pieces are present. It’s also possable that something else is locking up the engine causing it not to spin like a blown clutch bearing, maybe something came apart in the stator coil area or transmission.

Wow that’s a lot of oil. Prior to breaking it down I think I would give the engine a complete wash down with a can of gunk engine cleaner and make sure you have the location of the leak nailed down. Just to be safe.

Yes most likely a head gasket but this happens some times bc you loose a valve seal and the head gets oil inside the cylinder and during the compression stroke the gasket blows out. Have you done a compression test? Hopefully not the case here and just a gasket swap. And yes generally easy. Download the manual and get fimillar with the engine as well as YouTube the work. Between that and Quadcrazy member support I think you will have it up and running in no time. Post some more pics when you tear into it if you can please.

Forgot to mention. Have you pulled the plug and checked for oil on the spark plug?

Welcome to Quadcrazy, it appears from the picture that your head gasket is blown and hopefully not a cracked head. If you reved it as high as you said you did then it’s possable more damage was done like a valve seal but I don’t think so. You may get lucky and just need a new gasket. I would spray a soapy water solution where the oil was coming out and slowly crank the engine with the spark plug wire off so it does not start. You should see bubbles if its coming from the head where you see the oil leak.

Wow the bike looks like it’s in great shape I bet a good carb cleaning, fresh gas and plug like the boys say and she will fire right up. Keep us posted.

I agree with @Ajmboy. You can also find a used harness on eBay or other used atv parts vendors. I would rather take my chances on a used oem harness or a brand new oem one. The oem harness will fall right back into place and I’ve never heard one good thing about an aftermarket harness.

Nice work!

Any chance the fuel tank has junk in it ? Maybe remove the petcock (gastank valve) and check the screen and inside to check for junk and that it’s not starving the carburetor for fuel? Esp since you said when you start moving the bike around it gets cranky.

I’ve never used a timing light on a quad. Once the marks are set the timing should be set and locked. Unless there is a slacked chain maybe but that’s about it. The tdc on the compression stroke and the “T” mark on the flywheel are all good then maybe take a look at the trigger/pulse coil. Maybe somethings going on there. I also used a spark tester on the bike to see how the spark fires during engine rotation. But possibly the trigger coil having an issue. Was the head taken off the bike ? What’s the history from the person you got is from. The “it just quit on him” doesn’t sound right. Maybe he took it apart? Does it look like the head was taken off? New gaskets or any fresh marks like was taken apart other then the chain tensioner ?

Hey JD, welcome to Quadcrazy. I’m sure you double checked your work and I’m sure it all looks right. But could it be possbale that your are 180 deg out on the timing ? The marks are funny and there are a few different marks on the flywheel. It’s super important to have the proper timing mark and not just a line on the flywheel. It should be a “T” on the flywheel as a TDC reference point. Have you looked at the piston and valves to check for damage ? Maybe a blown or jumped chain caused damage. Have you tried staring fluid and sure the carb is clean and delivering fuel ? Reason im asking is it’s pretty simple if what you say is accurate by having spark, fuel and compression there should be no issues as far as starting. (Other then timing) Now having said all that the next step would be the stator and pulse aka trigger coil to make sure it’s sending spark at the right time to the spark plug.

I would only recommend a gasket sealer on the base gasket only if the cylinder is off. The head gasket is designed with compression pockets that flatten out when the head is tightened down sealing any slight voids. I highly recommend tightening then head down with a torque 🔧 to the engine manuals specs.

Can you post a picture of the carburetor?

#damgroundhog 12-16 here, maybe a little night ride later on with my boys. It is March right ? Be safe everyone. 😁

You are welcome and that’s great that you found some parts. That oiling system is going to be super important. Make sure that you have good flow. Also a ton of reassembly grease on all moving parts. That first start up will have a lot of friction.

Hey vertigo welcome to Quadcrazy, I picked up a bayou 400, same deal great price not so great head/cam. Journals were wiped out and the cam was burnt up. I contiplated a new cam and reworking the head etc but would up finding a used head assembly from a good motor on eBay for a good price. Glad I went this route. The bike runs like new and it’s all oem parts back on the bike. Good luck.

Welcome to Quadcrazy, I had one of the same type of bolts stuck. I used an impact driver. Got it on amazon. I put the link here to see. I hit it ever so lightly and the dam thing broke free. Good luck. I did have the engine hot prior to trying it. Once it broke free I let the bike cool and changed the filter. Good luck TEKTON 2905 3/8-Inch Drive Manual Hand Impact Driver Set, 7-Piece https://www.amazon.com/dp/B000NPPATS/ref=cm_sw_r_cp_api_u5DQAbJP361J6

I would check the timing marks that they are all aligned. Possible that the ignition system is not firing at the proper time. Maybe a pick up coil issue.

That thing looks absolutely nuts!

That I think was for a gps device like a garmin or something like that.

I agree with @Ajmboy it’s not really good to lay it on it’s side. Circumstances permitted ideally on all fours or up in the air.

Sorry the cdi I meant***