Engine Wont Turn Over

MRayNC

New Member
Jul 25, 2008
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Well, it was good while it lasted. Last night over halfway home, the motor locked up. All I did prior to that was tighten the chain because it was loose, and get some gas.

Any ideas?

Mike
 

stude13

New Member
May 28, 2008
404
0
0
north bend wa.
that is not good. pull the head to see if your barrel is gouged or scratched. if so your fuel leaned out for some reason. if so buy a piston, rings and barrel. before reassembly replace studs with quality hardware including washers and nuts.
 

Ranger

New Member
Aug 7, 2008
55
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27
Is if the engine is frozen you might just want to soak the thing in oil. It might work.
 

jasonh

New Member
Jun 23, 2008
1,590
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Longmont, CO
You say you got some gas, did you make sure that gas had oil in it? :)

Have you checked to see if the chain bunched up at the small sprocket on the motor? Some people have had that happen.
 

MRayNC

New Member
Jul 25, 2008
10
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The piston is stuck in the barrel. Any sure ideas on how to get it out?

Thanks!
Mike
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
236
63
up north now
Stupid quextion.

Are you sure the engine is locked, or is the chain locking the engine?
You said "the only thing I did was tighten the chain and get some gas".

You did mix oil right? If the piston is seized in the jug, it's probably toast. These engines have a nikasil liner and once scuffed, and compression lost, can't be re-bored.
 

stude13

New Member
May 28, 2008
404
0
0
north bend wa.
ok your piston is stuck right? remove head--lift barrel as far as possible--if you can get to piston pin, pull retainer clip and drive out pin--if not visible then place some wood between barrel and block, then tap piston.
 

MRayNC

New Member
Jul 25, 2008
10
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0
I had adjusted the chain tensioner before I started off. The day before
I refueled and used Lucas synthetic 2-stroke mix. I mixed it 30:1
because it was my second gallon of fuel. I got about half way home from
work and the motor stopped. I try to start it back but when I let off
the clutch the back wheel would lock up. I have since taken the top end
apart. The ring was broken and wedged in between the piston and the
cylinder wall. They are both trashed. So now I'm looking for a new
cylinder, piston and rings. Any advice as where I can get the best price
for these parts? After looking at buying all the parts separately it is
almost more cost effective to just buy a whole new kit. That way I will
have plenty of spare parts. I really enjoy riding the bike when it is
working properly, and as an added benefit I have learned a lot about
small motors.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
236
63
up north now
I'd just buy what you need. It's better to buy a set (piston/wristpin/ring/jug) together anyhow. Call any of the sellers, one will set you up.

Thanks for the complete update, something that is often overlooked.
 

stude13

New Member
May 28, 2008
404
0
0
north bend wa.
now that you know its a broken ring. please tell us if your piston has positioning pins to keep the rings from spinning. if so did a pin become dislodged. i have a powerking 80 and it does not have pins. mitch
 

MRayNC

New Member
Jul 25, 2008
10
0
0
Yes, the piston does have pins; and no the pin did not become dislodged. The reason why is that I had accidentally broke off a piece of the ring that was so small and reinstalled into the jug. Like I said previously, I'm not a mechanic and this is my first engine. I didnt realize that it would make that big of a difference, but now I know! Oh, and I ordered a Powerking 80 last night. How does it work for you? Any tips? Thanks! Mke.
 

stude13

New Member
May 28, 2008
404
0
0
north bend wa.
hi ray; that is how most of us learn what not to do. my motor is doing quite well. before install i replaced all hardware, useing allthread and dremel to cut the allthread, port the exhaust, expand hole in chain ring and shorten new #41 chain. what a tool. my motor only needs a few tickles and no choke to start. so far so good. happy motoring. mitch
 

Saddletramp1200

Custom MB Buiilder
May 7, 2008
1,444
46
48
Houston, Texas
Bummer. Did you use regular 2 stroke oil for break in? If not theres a good chance as to why it went south on you. The cylinder wall & rings needs the oil to break in properly. Syn. oil is so slick that the rings will not seat and will lock. At a high rpm the piston will tilt enough to gouge the wall & it's over in nano seconds. Fosil oil first, Then syn oil.
 

Fosscati

New Member
Jul 3, 2008
36
0
0
Ocean Shores, NSW
I have noticed a real quality fade on the piston rings in the last year. I just can't get any that last long at all. My old engines from 2006 don't have this problem.
 

Norman

LORD VADER Moderator
Staff member
Jan 16, 2008
2,605
2
38
68
pampa texas
syn oil or dino oil will not cause the piston to rock over and gouge the cylinder wall excessive clearance will cause that and no type of oil can stop excessive clearance problems only a properly fitted piston with the proper end gap on the rings.
I happen to like syn oil over dino oil. syn oil will out perform the dino oil hands down and syn oil IS used for break in oil on a bunch of engines.
a while back there was a bs story that syn oil is so slick that it would cause the needle bearing in a Harley to skid which is pure bs. all oil is designed to lube, carry away heat, and stop corrosion syn does all of that better than dino oils. syn oils don't break down with heat like dino oils will.
I'm not wanting to start an oil war just telling a few things that I've learned about oils from working in the oil patch and working on engines and compressors and attending the schools on same I'm still no expert.
 

Saddletramp1200

Custom MB Buiilder
May 7, 2008
1,444
46
48
Houston, Texas
I got this info about the piston from a Honda Mech. I use Amsoil Myself. But I have seen things that were thought impossible and happened any way. Don't know. Thats is why the Forum Rocks!!!