Engine Will Not Turn Over

GoldenMotor.com
DuctTapedGoat

DuctTapedGoat

Active Member
Dec 20, 2010
1,179
10
38
38
Nampa Idaho
Thanks guys - the motor is a Raw 48cc.

Jumpa - I'm coming out of my busy season (pc repair), as soon as I get everyone taken care of I'll get on a new set of clutch pucks for ya.

Syates - For your problem, I'm pretty sure your clutch needs to be properly adjusted. You don't adjust the clutch via the cable, you adjust the clutch itself via the clutch plate height off the pucks.
 
DuctTapedGoat

DuctTapedGoat

Active Member
Dec 20, 2010
1,179
10
38
38
Nampa Idaho
Lock the clutch, remove the clutch cover, remove the lockscrew and tighten the flower nut. You want it set where you can have the clutch locked and not have it grab, but unlock the clutch and it won't slip.
 
N

nightcruiser

New Member
Mar 25, 2011
1,180
2
0
USA
I notice on my 66cc gt-5 that when brand new the compression was on the low side, it turned over easily and smoothly and would turn over with just a slight roll of the bike. After I rode it a while and the rings started to seat the compression on the motor seemed to increase and it started requiring more of a roll to get her to turn over and start. Sometimes it turns over and fires real easily, other times it seems to offer much more resistance, I guess it depends on what part of the stroke its in. I think maybe this might be your 1 in 6, when you pop the clutch right at the compression stroke.
When you pop the clutch a second time does she turn over and start, or are you seemingly seized up and unable to get her running at all? If she starts on second try I wouldn't worry about it, I would continue to break her in and assume after a good number of miles the compression will fall off a bit and this problem will go away.
Another poster mentioned a carb leak that was loading his cylinder with fuel after the bikes been parked. First thing I would say is turn off the fuel valve when you park... It seems liquid gasoline would be harder to compress than the air/fuel mix the motor is used to seeing, so if you have liquid fuel in the cylinder during the compression stroke it would be harder to turn over is my guess. Not sure this would relate to your situation. If you do have fuel loading your cylinder then I would tell you to check your needle valve and/or adjust the float...
 
2door

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
Fact: You cannot compress a liquid.

That's the whole principle of hydraulics. If the combustion chamber has enough fuel in it, the liquid will be as non-compressable as if there was a hunk of steel in there.
This is why I suggested to the man that he remove the spark plug and pedal the bike around for a bit to clear out any possible excess of fuel then try reinstalling the plug and seeing what happens.

If the slant head's higher compression is in fact the culprit then adding a second head gasket might be the answer. My question then would be, what's the advantage of a high compresion head that won't let you start the engine until you lower the compression? Seems a little redundant and a waste of money to me.
Tom
 
S

syates234

New Member
Jun 14, 2011
36
0
0
idaho
Thanks for the info I did in Fact do all of that then another poster told me to check the clutch, soni did and it fires right up no problems
 
N

nightcruiser

New Member
Mar 25, 2011
1,180
2
0
USA
2door said:
Fact: You cannot compress a liquid.
This is why I suggested to the man that he remove the spark plug and pedal the bike around for a bit to clear out any possible excess of fuel then try reinstalling the plug and seeing what happens.
Tom
Click to expand...
I have done this myself and recommended that others do this as well in a flooded situation. However, after reading the thread from the guy who set his crotch on fire, LITERALLY, I would always include a cautionary note! Make sure the plug wire or any other source of spark is far away from the motor when you do this. I usually set a clean rag loosely on top of the head to soak up any gas that might get pushed out of the spark plug hole. (make sure whatever you use can't get sucked in!) The guy who got set on fire posted pictures, OUCH!!!! Even worse than his crotch being set on fire, his bike got totally toasted....
 
Last edited:
2door

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
Sorry, I can't see how adjusting the clutch would have anything to do with an engine that will not turn. Yes, you could adjust it enough so it slips, but that's not correcting the problem the OP described. Something doesn't make sense here.

My guess? He wasn't pedaling fast enough to begin with and with a clutch that now slips a little he is getting the engine to rotate at a lower speed and the slippage is just enough to turn the engine over and it starts. This will come back to bite him later with a clutch that will wear out prematurely. The reason he was able to start it early on was because the rings hadn't seated enough and when they began to, his compression went up and he wasn't compensating for that by pedaling faster.
Again, just my guess.
Tom
 
Last edited:
N

nightcruiser

New Member
Mar 25, 2011
1,180
2
0
USA
2door said:
Sorry, I can't see how adjusting the clutch would have anything to do with an engine that will not turn. Yes, you could adjust it enough so it slips, but that's not correcting the problem the OP described. Something doesn't make sense here.

My guess? He wasn't pedaling fast enough to begin with and with a clutch that now slips a little he is getting the engine to rotate at a lower speed and the slippage is just enough to turn the engine over and it starts. This will come back to bite him later with a clutch that will wear out prematurely. The reason he was able to start it early on was because the rings hadn't seated enough and when they began to, his compression went up and he wasn't compensating for that by pedaling faster.
Again, just my guess.
Tom
Click to expand...
We are on the same page, that's why I asked what he fixed/adjusted on the clutch to make his motor turn over easier...
I had the same experience, re: compression rising after rings set, more riding and breaking in the motor made compression ease up a bit and starting easier. Also, tuning my (CNS) carb made starting MUCH easier. Now I can lift the rear wheel and start my bike with the pedal like a kick start! In the meantime, just make sure you got enough speed going when you pop the clutch to start her up. Don't adjust the clutch to allow slippage by any means, you don't want your clutch to slip (and wear), you can simulate clutch slippage by letting out the clutch lever slowly if need be....
 
S

syates234

New Member
Jun 14, 2011
36
0
0
idaho
I took the clutch apart down to the pads, took all the pads out and cleaned the whole clutch making sure not to get cleaner on the gears and then reassembled the clutch. Tightined the flower nut and put the. Cover back on. I also flipped the pads Around cuz they were kind worn but still good. Make sure you use brake and parts cleaner though. After that it fired right up with few pedals. Check out video
how to fix a sliping cluch on your 80/66cc bike engine kit - YouTube
 
O

openscreen

New Member
Oct 1, 2011
14
0
0
Oregon
I wanna thank everyone for their input. Unfortunately my internet connection has been out for a while and I have not been to read, much less try out, all this good stuff. I hope to be able to get to it soon.
 
Jumpa

Jumpa

New Member
Aug 12, 2011
607
2
0
Cape Cod
2door said:
Sorry, I can't see how adjusting the clutch would have anything to do with an engine that will not turn. Yes, you could adjust it enough so it slips,
Click to expand...
Not so much adjusting it as much as cleaning it out and getting all the shavings out. a slipping clutch will not let the engine turn over so If he tightens the nut a little more he just might get the bite he needs to make it able to turn over the engine and not just grind away at his clutch So yes a slipping clutch can have everything to do with a motor that wont run. Also DO NOT BUY THE HAND PULL STARTER . Especially with that slant head It will ruin your arm. Compression on these motors (When they are brand new) is way to much for a pull starter I'm in awe that no one has come up with a kick starter for these yet.
I'm no flower and my pull starter kicked my azz The first time I pulled it the bike came a foot off the ground and the kick stand came down on my foot OUCHHH! The second time it ripped out of my hand and it felt like I ripped off two fingers & I pulled a muscle in my inner forearm There wasn't a 3rd time. I destroyed it with a hammer
 
Last edited:
  • Like
Reactions: Robert T Spurlock
Jumpa

Jumpa

New Member
Aug 12, 2011
607
2
0
Cape Cod
syates234 said:
I'm confused my crank doesn't even want to turn my tire moves but it won't turn the crank it seems to me I'm not getting fuel to the motor. Damn Chinese
Click to expand...
If you get a head with the plug hole in the center all your problems will go away as far as not turning over when the rear tire is spinning. For some reason the slant heads produce a bit too much compression for these clutch set ups.
I had the same exact issue I swapped out heads and blamo all set . You can do it right on the bike it took me all or 10 minutes ..seriously
:-||



 
N

nightcruiser

New Member
Mar 25, 2011
1,180
2
0
USA
Jumpa said:
Not so much adjusting it as much as cleaning it out and getting all the shavings out. a slipping clutch will not let the engine turn over so If he tightens the nut a little more he just might get the bite he needs to make it able to turn over the engine and not just grind away at his clutch So yes a slipping clutch can have everything to do with a motor that wont run. Also DO NOT BUY THE HAND PULL STARTER . Especially with that slant head It will ruin your arm. Compression on these motors (When they are brand new) is way to much for a pull starter I'm in awe that no one has come up with a kick starter for these yet.
I'm no flower and my pull starter kicked my azz The first time I pulled it the bike came a foot off the ground and the kick stand came down on my foot OUCHHH! The second time it ripped out of my hand and it felt like I ripped off two fingers & I pulled a muscle in my inner forearm There wasn't a 3rd time. I destroyed it with a hammer
Click to expand...
From my understanding it was the motor would not turn over and the wheel does not turn? I guess maybe I was mistaken, cause it sound to me like you are saying the motor doesnt turn over but the tire rotates (clutch slipping), different deal all together. Anyways, I think we have a second person who chimed in on this thread with their problem, might be part of the confusion...
 
DuctTapedGoat

DuctTapedGoat

Active Member
Dec 20, 2010
1,179
10
38
38
Nampa Idaho
Original poster is Openscreen who has a compression problem, and I think 2door nailed it in the beginning with the hydraulic lock. I guarantee you that he DOESN'T have a clutch problem.

Syates had a clutch problem and he is solved.
 
You must log in or register to reply here.
Top Bottom