Pros/cons/opinions of chinese engines for atc90

[bigcal]

I have a 78 ATC90 I got for my kids that is needing some work. looking at opinions on the all the Chinese 12v engines available that fit into these machines. I like the 12v cdi upgrade, but the ole points been going for 37 years. personally I don't have any problem spending a few hundred $$ to have the original engine like new again, and I would prefer having oem instead of something Chinese. Just looking at going back to stock for kids, don't need some big cube pit bit etc. any goods/ bads with the Chinese repowers? opinions on things you have already done? do the engines have any longevity? or worse off in the long run

I do think any value in the future would be greater with the oem powerplant.

thanks

[YTZ drew]

If you're concerned about value, stick with the original engine. The Chinese engines are mechanically OK, carbs are sub-par to a genuine Keihin. Also, no Chinese engine is a bolt-in to a 90/110. All the ones I have seen use the Honda 50/70 mounting dimensions. Some fabrication will be required to put one in a 90.

[joels]

Yes i agree with ytz drew they bolt in to atc70 frames. I had a lifan engine in a atc70 frame. It was a 125cc semi auto trans like the stock trans. It ran great but shifted wierd. It would not shift smoothly from 3rd to 2nd. It made it hard to ride. I dont recommend.

[bigcal]

ah, OK. have seen a ton of 70's with Chinese/lifan motors and assumed that some of the larger ones would fit into the 90. will definitely not go that route. thanks

[freewheeler]

Its not that much work to put those engines into a 90. DRATV makes a conversion kit.

[bigcal]

I have started tearing down the motor and will be rebuilding it. going to go all the way through and check crank bearings, oil pump, bore sleeve, valves etc.

[86125m]

I do not believe that you will need a bore sleeve If you still have the stock piston and rings in there and it doesn't appear to be a lot of ware on the piston or the cylendar just have it honed and put new rings on the original piston and run that sucker.

[bigcal]

I do not believe that you will need a bore sleeve If you still have the stock piston and rings in there and it doesn't appear to be a lot of ware on the piston or the cylendar just have it honed and put new rings on the original piston and run that sucker.

i just meant that i will be fixing what needs to be fixed. the piston and sleeve are scored. I will have it bored to fit new piston. also top ring was broken. makes sense to me do the job right instead of slapping something together. not that you were implying that, if it doesnt need boring, no sense in doing it, yes.

[86125m]

yes I agree if my engine was that bad I would probably find another cylendar to replace it and double and triple check everything else

[ps2fixer]

I might have a US90 top end, pretty sure they were all the same if you wanted to replace instead of bore larger. If interested shoot me a pm and I'll check it out, get photos etc.

Another note on the China engines, w\e the orig size of engine was, you will want to go up at least one size, as the china engines put out less HP than the 30+ year old Honda engines did when new. I don't have much personal experience with them, but seems they are made of lower quality material that breaks easier. The ones with the starters mounted on the bottom of the engine seem to break off quite often while the top mounted starters (different brand) seem to hold up fine.

I have a few misc 1976 ATC90 parts left over from the machine I used to have including rear fenders in fair to good shape, but I'm not sure what kind of shape your machine is in. We always love photos btw .

[bigcal]

well i bought this 78 atc90 pretty well sight unseen but was told it ran. i was having trouble getting it started after i got it home so i decided to pull the plug, have a look, maby it was flooded, maby do compression test. turns out the plug hole is stripped badly dont know how previous owner even got it started for me at drop off, so i take the head off and locate one on ebay planning to install new valves. i checked the cylinder while im there and find scoring... so i yank the whole thing and currrently its partially dismantled. I do plan on taking some pics, but currently trying to repower a wheel loader, get out fall crops after full time day job, finish a waterway for neighbor, and on top of that we have the brilliant daylight savings time. so i get to go to work in sunlight and get home just in time to do nothing before it gets dark....

also, the ebay vendor sends me a cylinder instead of the head that i ordered, so now i have an extra cylinder. dratv has a cleanup cylinder bore deal that is cheaper and easier than my not so local machine shop.

[TubergenMtrSprt]

The new Great Debate for sure!,, I also vote rebuild Honda We have a 1975 ATC90 Still starts first pull! I'm thinking the Chinese engines won't make it 40 years!

[ps2fixer]

The new Great Debate for sure!,, I also vote rebuild Honda We have a 1975 ATC90 Still starts first pull! I'm thinking the Chinese engines won't make it 40 years!

They could.... if they sat around enough =)

[RamsesRibb]

I had a little Chinese quad a few years ago that lasted maybe about 4 years before the engine failed. It was never ridden hard, just around the yard. I almost sold it because my son outgrew it pretty quickly, but decided to keep it for my daughter.
Bad idea. After sitting for a while I got it started and took a couple spins and the engine made a thud. Hit the starter and sounded like a free spinning chain.
I looked into repairing it. Couldn't find parts. The manufacturer was Xian something.
Ended buying a ATC110.
Gave Chinese bike away to a junk collector.

[azskateman]

The GPX motors have been really good