Thinking of modding my 79cc

mark20

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Sep 26, 2018
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I just have a ryobi drill and some torque wrenches. I just don’t get why deez nuts won’t move. I can see the stud bend when I try to loosen. I don’t even have an attachment to attach a socket to the drill.
Just attach it to the nut, set the drill to max and PRAY it will loosen, could help if you put some pb blaster or a torch
Ie set the locking collar in the bolt and tighten it until it makes contact. Then set it in reverse and it should break loose!
 


Frogslayer

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Jan 20, 2019
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A drill won't have the hammer action you need. Is this the exhaust valve by chance? I would use a little pencil torch to heat the nut, try not to heat the stud as much as you can help it. Don't you have to use two wrenches on that engine? One on the stud and one on the nut? Other wise some kind of impact driver would be your best hope. When worse comes to worst a hammer smacking the end of a wrench is an impact driver lol.
 

Will'smotobikes19

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I can borrow my neighbor's torch yes I saw redbeard's video i put a small adjustable on the bottom one and a 10mm socket on the top didn't move at all.
 

Will'smotobikes19

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Ok did the valves and put everything back on. Set lash to .006. I also chopped my muffler in half for more power. The plug is a Bp5hs and it has stock 212 springs in it now. I guess the flex was because I didn’t have a 14mm box wrench for the bottom nut but my cousin got the nuts off.
86196
 
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Will'smotobikes19

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Well now it has no compression from the spark plug hole, wtf. Yesterday it did when we were adjusting it. The rockers are moving but it has a lot of resistance on the pull start. Why just why. Unless my cousin messed something up. The cam fell out and I put it back in and it should have been lined up. Already put gasket maker on it
 
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JerboaJohn

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Jul 29, 2018
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uhohs. sounds like the cam timing is off. gotta pull it apart and check that and valve lash at the rocker. don't think piston is smacking a valve unless you changed pushrods or anything? no gasket, just the rtv gasket goo?
 

FNTPuck

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Jul 2, 2018
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Well now it has no compression from the spark plug hole, wtf. Yesterday it did when we were adjusting it. The rockers are moving but it has a lot of resistance on the pull start. Why just why. Unless my cousin messed something up. The cam fell out and I put it back in and it should have been lined up. Already put gasket maker on it
Could be a few things.

Too much lash is the likely culprit. That will cause the intake or exhaust valve to never close, bleeding compression so ending up with low numbers. Also, it can make you hit coil bind which will explain the resistance when pulling it...

Other cause could be way out of degree cam, which would explain low compression and cause a valve to push against the piston making it hard to rotate the engine.

Both can cause serous issues so don't try to start it until you find the cause - you could wipe a cam lobe, ruin a valve, fatigue a spring, etc. This is why I warned against just throwing in a different height spring since you may need an out of spec lash setting, valve cap, spring seat, etc to put the geometry back where it belongs.
 

Will'smotobikes19

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Ugh this is so frustrating I’m trying to adjust the dumb valves right now. It it now building pressure but the rockers automatically got sloppy and loose. I think you’re right about the spring as the rocker seems to put a light pressure on the valve at tdc when. I went down to .005 and it is pushing air out but the rockers are sloppy like I said. Maybe .004?
 
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JerboaJohn

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the rockers are stamped steel and have play when new in lots of engines but I think it's the nut that's limiting vertical movement more important. but it can rock on the stud. is it up n down wiggly or ? rotate by hand or wrench when you try a setting
 
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