79 atc 70 clutch issues?

[Jim mac]

got a new trike today! atc70 its a 79, got it running but the guy I bought it from told me it grinds when in gear and under load. Sounds like the clutch and the clutch gear isnt meshing. Is this something that happens? Ive got a china 90 motor, im going to see if I can use the clutch assy and gear out of it, if not im going to order up new parts off dratv.
Also needs wheel bearings, but it doesnt smoke and most of its there. brakes work, kill switch works.
Im missing a air box but I have a spare and a extra set of new tires sitting in the shed. jim

[shortline10]

Pull the clutch cover and take a look . The large drive gear on those are kinda fragile so see if its missing any teeth . Could be as simple as a loose worn sprocket / chain also !!!!!!

[Jim mac]

Pretty sure its not the chain, but I'll pull the side cover off to see if its overiding the sproket. jim

[Jim mac]

installed a half link and tightened the chain. No good. I pulled the clutch cover the triange thing with the ball bearings dropped out? balls are still in the cage. Just for giggles. I fired it off in gear and now there is no noise. It goes! I shut it off after a couple seconds because there is no oil. Im going to put it back together and see what happens. I did try to pull the phillip head screws from the clutch cover, using a impact screwdriver. Maybe something knocked itself back together? The clutch basket thing and the ring gear both looks fine. jim

[Blown 331]

When it grinds can you feel jumping or slipping or is the noise your only symptom? Does it make the noise on acceleration but go away on deceleration?

[Jim mac]

Okay here we go. I installed the clutch cover. I believe its popping out of 1st gear and grinding. If I slowly put it in first sometime it will fully engage, but once you get it under load it pops out and grinds. I can put it in 2nd or third and it seems okay in those two gears. Unfortunatly the tires on the trike suck. 1 rear tire is filled with rags and sewn back together just so it rolls, Im going to swap some tires, later, but does that sound like a bent shift lever (internal?). I tried the foot lever in every position but it either goes into gear or sits and grinds. jim

[Blown 331]

If it jumps out of gear it almost sounds like it might not be fully engaged. Maybe the shift drum stopper is broken? It's a pretty common problem, I just fixed this on 1 of mine. If that's not it I'm guessing your shift forks are probably worn. I have had a few of those also, unfortunately you have to split the cases to fix that.

[Jim mac]

its too bad, this thing runs really good. I may throw a set of tires on it and see what running around in 2nd and 3rd feels like.
What chinese pit bike can I use as a donor for a swap? jim

[Blown 331]

Any of the Chinese knock off's should work. You can check the shift drum stopper just by pulling the clutch cover. Its pretty tough to see but you will be able to look in there. If its broken you have to pull the clutch and driven gear to replace it. You need a special clutch tool socket but its not bad.
I just picked up a 79 as well. Ran great, no noise, no smoke etc, but in first gear it would kind of jump- no grinding though. I checked the shift drum stopper and it was good. I had another engine so I just swapped that in, good to go now. To me it's not worth spitting an ATC70 engine to fix the transmission, they are too easy to find. Now I have an SL70 that had a transmission problem, I split those cases to fix that one.

[Jim mac]

I just threw a couple ads on craigslist to see if I can come up with a pitbike or another motor. Trying to trade off some of my car parts, these parts arent selling like they use to. So maybe I can get some use out of them bartering
69 chevelle bucket seat cores
BBC performer intake
750 holley vacuum secondary
GM floor shift tilt column for camaro, chevelle, lemans, gto etc.
We'll see. jim