Joeguy

Ya from what ive seen most are .020, should clean up way before that but ill take it all to em.

Im just going to gamble on the bottom end because im lazy and it feels ok i believe, might be a waste of money but oh well. I didn't notice that the rebuild kits say what the bore should be till i just looked so ill get that done, luckily my buddy can get it done cheap for me. Hopefully be getting it back together after that, and we shall see if my cheaping out is going to work ha.

Also dumb question but how much space should there be between the piston and the walls of the cylinder? Like if i buy an oversize piston should i get it bored out to like maybe 5 thou larger than the piston? Im just not sure how tight of a fit it is supposed to be.

Well i changed the filter when i first got it and i did not see anything but i guess ill have to drain it and check it all again. Do you know where the sieve is at on this? If not ill take a peek through the manual.

Doesn't appear to be lifting i think some chunks got in there. Rocker has a small mark on it, i think i can feel a small something there but nothing i can like catch a fingernail on or anything.

Man now i just noticed i need a camshaft ha, just keeps on adding on. Some how did not notice this till today when i was wiping everything down.

I measured with just some cheap bore gauges and my digital calipers so its not the best measurements probably. Ill see if my buddy that does ID work can bring me better stuff to check.

Hmm i guess ill price out a local shop then, to bad i quit my other job that had a Sunnen or id just do it myself. This was a really cheap purchase and the quad is kinda beat up so im not too keen on spending a bunch when i could just sell the parts off this one and put that money + repair/parts bill and get one that already runs. Been a fun experience so far atleast, and learning.

Ok well i checked the bore over and got a roundness of like .0015 and a taper of .003. That ring does not seem to be a ridge its more of an undercut and it seems to be like .002 deep but im only checking with some cheap bore gauges so its kinda hard to tell exactly. The bore was at 2.601 inches and the piston was 2.586 inches. So would you recommend that i try to clean that ring up a bit with my hone or would it be ok as is.

Ah damn i only tested at tdc, its like .100 side to side at that point if that matters ha. Ill have to check again properly tommorow. I did hone out the cylinder a bit today and it seems like it cleaned up well except for right at the top there is a bit of an indent, ill have to get my bore gauges and check and see how much it actually is aswell as the rest of it.

Also anyone know why the 2nd ring and the piston were like shattered into pieces?

Wish a top end rebuild kit wasn't like a hundred bucks. Im going to do so actual testing and measure on that rod and see how its looking because honestly it feels smooth and doesnt have much play if i like pull in and out its just side to side. Never done much engine work except like weedwacker and tractors so im gettin a bit more involved here.

Well got bored today and tore into this thing finally. Bad news, we got damage. Also, ya it at least needs a bearing in the bottom end. What a nightmare to get this thing apart, i do not enjoy working on this thing at all. I am not excited at the though that now i would need to pull the engine to fix it so i think it might just be junk time. You guys think its worth the time and money at this point? It seems pretty beat to me. 20241124_170300.mp4

Same, i got it because of price and ive beat on this battery using to on my go kart, motorcycle, and now the atv lol. Still kickin, will definitively buy more so i dont have to use 1 battery and swap it between everything. Ive got about 3 years on mine so far.

Honestly i started to work on another quad and got it running pretty easily so now im kinda wondering if i even want to put the money and time into this one. Might keep it around as a project for later but i dont got a whole lot of free room. I did however fix my big hole in the fender with a plastic welder, i only have staples in it now but it looks alot better than zip ties.

I actually just went through this with basically the same quad and my problem was that the person before me had the white wire that goes to key switch spliced in the middle and going to some other wire instead. So ya like these guys are saying just check all wiring and atleast get power up to the key switch.

Ya if the crank is bad im just going to junk it sadly. Hopefully an easy fix.

Thanks, gona have to figure out how it all comes apart with the rear end being like part of the engine. Looks kinda simple atleast.

I been working on this thing for like 2 months now and it will not run right, is very smokey, and has a pretty loud tap that i think is in the bottom end. Not sure how much the parts are but i will put the time into it if they are pretty cheap. Im not very experienced but going off how the plug looks and the oil on top of the piston i am getting a whole lot of oil coming in from somewhere, not sure if it can come from the valves or if the rings are just shot, my cheap scope cant really see the walls of the cylinder too well. 20241009_123850.mp4

It has ran for like a minute or 2, i moved it a bit just to check if it would go into gear, but its not really ride able at the moment. I showed another guy and he agreed it looks like it was hit a while ago because there is buildup on that mark too its not fresh metal. Im reading though the manual i downloaded and re jetting the carb and stuff to get it to run good hopefully, i jsut got really worried when i saw that mark.

Well compression isnt great, my super cheap gauge says 125psi, but idk how long it has been sitting so maybe itll gain some after it runs a bit. The oil level is at the top line on the sight glass so maybe i over filled a bit. Also it is a 1991 quadrunner 250 lt4wd.

So i bought a chinese carb and in messing around still trying to get it to run right i figured id pull the spark plug to see if it was running rich, well it was definitely but also i have a nasty mark on the strap (i think thats what its called) that looks like the piston has been smacking it. I never actually pulled the plug because i had it running for a second on starter fluid when i first bought it and was just stupid and figured whatever was in there was good. The part number on it is DPR7EA, which is similar to what is called out for in the manual but i assume the little bit off that the code is means it must be a bit longer or something. Unless the plugs are made like this, but i can pretty easily see that metal has been pushed away from the area of impact. What are the odds that my piston is trashed now you think? It does still run just not well due to carb issues but thats a whole other problem. Actually i just took a second to google both plugs and it says the reach is the same its just different resistor values and gap size, so maybe the bigger gap is why its hitting. Either way the actual one for it is on the way and i hope it just didnt do to much damage. Wish i woulda just went over the whole thing like i normally do with this stuff.

Ya ill order it and then post pics of how it comes out when i get er done.

Its actually like a 8 inch oblong hole in the fender im going to try and patch with like a red harbor freight bucket to at least kinda look normal ha. Might try out that plastic welding with some extra glue to cover.

I meant saw it pumping fuel, not coming from the vac line my bad. Should have er going this weekend hopefully once this all comes in. Then i gota fix the plastics on it, you know any glues that work? I have an epoxy for thermo set plastics i was going to try.