80cc engine seizing

GoldenMotor.com

dndory

New Member
Sep 7, 2014
17
0
0
IL
I have just installed my motor it is an 80cc 2 stroke. I have been unable to start the engine. After attempting to start it the gasoline was leaking. I was able to stop the leak from what appeared to the car berate I can't spell.. the leak stopped on its own and I am still unsure what caused the leak to begin with.

After letting sit for a fee hours I attempted to start the bike again. When I release the clutch the rear tire seizes. I attempted to adjust the clutch after I had removed the spark plug the tire was rotating. After adjusting the clutch it continues to seize when I put the spark plug back in. I think it could have to do with air flow but I am really unsure and hoping for assistance.
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
How fast are you going when you release the clutch? You must pedal up to about 10 MPH before engaging the clutch. After the engine starts you must disengage the clutch when the bike's speed drops below about 10 MPH.

What do you mean when you say, "I attempted to adjust the clutch" ? What did you do?

Tom
 

a.graham52

New Member
Nov 22, 2013
232
1
0
island of misfit toys, maine
if the carb was leaking fuel (out the air filter?) im woundering if it filled the engine with fuel. try removin the plug and spinning the engine over with a rag on top of the spar plug hole. mind you keep the plug wire away from the engine and see if any fuel comes out the spark plug hole.
 

dndory

New Member
Sep 7, 2014
17
0
0
IL
I loosened the clutch. I had tightened it earlier. When I take the spark plug out it stops seizing. I had read that if the seizing stops it could mean the clutch needed to be adjusted. This is why I loosened it. Could it be possible that I am adjusting the clutch incorrectly, having an airflow issue, or possibly something else entirely
 

crassius

Well-Known Member
Sep 30, 2012
4,032
158
63
USA
I'm not sure if you are using the word seize correctly here. With the clutch lever pulled in, the back wheel should turn easily whether the spark plug is in or not, When the clutch lever is released, the back wheel should turn just a little stiffly with the plug out, and be hard to turn with the plug in.

If this is where you are, you may be OK and just need to peddle faster before letting out the clutch.

If the engine will not turn at all when the plug is in and the clutch lever is released, it may be that the engine is full of fuel (you can take out the plug and turn it upside down and turn the motor till fuel stops coming out, or wrap a rag around the head and peddle with the lever released till it seems dry) - it may also be the case that for some reason, the plug is getting hit by the piston, in which case you must open the top & see what is wrong (a pic here would be good)
 

dndory

New Member
Sep 7, 2014
17
0
0
IL
I'm not sure if you are using the word seize correctly here. With the clutch lever pulled in, the back wheel should turn easily whether the spark plug is in or not, When the clutch lever is released, the back wheel should turn just a little stiffly with the plug out, and be hard to turn with the plug in.
The clutch lever is released and the wheels are not rotating .. its so difficult to rotate it. I tried to take the spark plug out and the clutch lever released, it rotated a little stiffly just like what you have said. I think the problem is related to air pressure inside the engine!
 

crassius

Well-Known Member
Sep 30, 2012
4,032
158
63
USA
Have you tried to start it by peddling fast and then slowly easing out the clutch lever while still peddling?
 

dndory

New Member
Sep 7, 2014
17
0
0
IL
Have you tried to start it by peddling fast and then slowly easing out the clutch lever while still peddling?
No actually, I'll try it now and I'll let you know. I'm checking the engine now if there's gas inside it or not.
 

Greg58

Well-Known Member
May 1, 2011
5,353
2,575
113
66
Newnan,Georgia
Lock in the clutch lever and then try to spin the wheel, that should let the wheel turn if not the clutch needs adjusting. As was said earlier you need to check the carb leak first by removing it and checking for debris in the needle and seat or setting the float level correctly. After the carb work pedal to 6 to 8 mph and release the clutch to crank the engine. My carbs are jetted right for my engines so I have to choke both to get them started.
 

Kioshk

Active Member
Oct 21, 2012
1,152
10
38
Connecticut
I'm with Dave31; your engine seems fine, the difficulty in turning the engine over is a GOOD thing: it indicates good compression. Have you checked your spark? Also, I noticed that your drive-chain seems tight; this can impose undue stress on the drive-train and increase rolling-resistance. Consider resetting your idler pulley so there's a little slack in the chain.
 

dndory

New Member
Sep 7, 2014
17
0
0
IL
I've adjust the clutch and I checked for spark ..
Everything seems great now

I tried to go to a hill and run the bike but it didn't run.
The gas is mixed for 2 stroke and it makes noise like it wanted to start but it doesn't actually?
 

crassius

Well-Known Member
Sep 30, 2012
4,032
158
63
USA
for the first start, you may need to try choke on, choke off, or maybe halfway choke

shouldn't need a hill to do this, just pedaling
 

dndory

New Member
Sep 7, 2014
17
0
0
IL
YES. I did it.
It works great. The problem was with the Carborator .. I had it upside down. Now it's working fine for the first time.
Thank you people. I really appreciate your help.