79cc motorbike build questions - thanks!

Will'smotobikes19

Well-Known Member
Joined
Apr 9, 2018
Messages
1,362
I'm using mounts like that, but not vertically lol. mine doesn't have beveled edges but Gasbike has em for the best price on the site, like $60
I saw some of the upright mounts for like $50 on eBay. I kinda want to do that with my 79 after I mod it. I can’t get the stupid adjustment nuts off the valves don’t want to snap the bolts either. I put a long pipe on a ratchet and they didn’t budge. Low and behold the left valve rocker was way too loose as well. Hoping the little 79 can do 40mph. I’d guess stock hemi 212 springs are more lbs than stock 79? I plan on taking the ones from the 212 and installing them in the 79cc.
 
Last edited:


Will'smotobikes19

Well-Known Member
Joined
Apr 9, 2018
Messages
1,362
No I think you just need to make sure the oil level is appropriate maybe a piece of plexiglass could be used to see how much oil you need.
 

MotorBikeFab

New Member
Joined
Sep 9, 2018
Messages
19
I like the way the engine is mounted. Where did you get the engine mounts?
Thanks for your kinds words. I made the motor plate and clamps myself. Gone through a few mods since then. Will post pics of the progress soon. Also, I changed the look to more traditional...wait for the pics. Thanks.
 

Will'smotobikes19

Well-Known Member
Joined
Apr 9, 2018
Messages
1,362
Well on my 79 it’s almost as if the nuts on the valve rockers are welded. They won’t budge even with a 4 foot long cheater pipe. The whole stud bends. I think the 14mm nut under it is locking it maybe but idk. My clutch is stuck on the shaft so I’ll have to pull it.
 

MotorBikeFab

New Member
Joined
Sep 9, 2018
Messages
19
I hear people are using about the same (how's that for imprecise?) amount of oil. About 16oz. There are quite a number of builds now for 79, 99, 212 and there are no oiling issues with the engine mounted on the seat post.
 

Will'smotobikes19

Well-Known Member
Joined
Apr 9, 2018
Messages
1,362
I remember someone saying on the flathead Briggs bikes if it’s angled have to add a bit more oil but might be different for the predator. It’s too bad they don’t make the 99cc anymore it would bridge the power gap.
 

Will'smotobikes19

Well-Known Member
Joined
Apr 9, 2018
Messages
1,362
If you machined that yourself good job. I worked as a machinist for a week just tended the cnc really. Didn’t like it much so I left. I’m working on a 212 mini chopper.
 

MotorBikeFab

New Member
Joined
Sep 9, 2018
Messages
19
I took a few machining classes at my local community college. All manual work no CNC. I'm ok but no machinist.
 
Top