Possible locked engine or Clutch issue...??

[Rusty Nail]

Hey guys. I recently bought another MT. I did the break in and was starting to tune the motor and the truck died. I seen that it had proper amount of smoke when running but when I pulled up to do a little adjustment to the HSN, it died and that was it. I couldn't get the thing started one time after that. I thought well I must have flooded it so I took out the spark plug, drained the gas tank, turned truck upside down then let it sit for about an hour with no plug to air out. I put the plug back in and the thing wouldn't even pull!


So I took the pull cage off and looked at the pull assembly and it all is working fine. I manually turned the shaft to see if the piston would turn. It turned but would not make a whole revolution. I took the motor off of the truck to inspect more. While the motor is off it turns over and the piston moves freely. So I put it back on and then it started turning with the rope assembly until I put the plug back in and tried to pull and it tightens right back up. I take the plug out and it turns freely.


Did I destroy my motor. I'm just a newbie tearing things up but I try and figure it but I need some advice. My buddy said it appears that I might need a new clutch or maybe a new top half of the motor. Any help with would really be appreciated. I'm bummed, I haven't had the thing but two months. My other MT works pretty good and it's a few years old now.

 

[Ice_2k]

well, if it works fine with the plug off, I'd say that pretty much rules out the clutch. As for why it doesn't turn with the plug installed, maybe someone with more experience will chime in. Only thing that I can think of would be something blocking the exhaust?

 

[RampageHopUps]

Pull the motor out of the truck and try to start it.

 

[talunceford]

Pull the motor out of the truck and try to start it.

I concur with that. I'd mount that thing up to a block or something and try and start it. When it is out of the truck, with the plug in it, can you pull the starter? If you can, is that with the exhaust on it, or off of the engine? Is there somthing blocking the clutch bell? Can you turn the clutch bell freely when the engine is out of the truck? Can you tell if the spring is broke on the clutch? Just throwing out ideas to check.

 

[talunceford]

Oh, one other thing, were you running it in any rocks? If you were, I'd check to make sure that no fins on the flywheel are broke and lodged. Try and isolate areas of the engine/drivetrain.

 

[Rusty Nail]

Thanks for the help guys. I will take it out and check all the things you guys were suggesting.

 

[Rusty Nail]

Ok I took the motor back out and try to start it with the plug in and exhaust on. When I pulled the rope it did pull BUT it was really jerky or rigid, not a smooth pull at all...if that makes sense. I pull the plug out and it pulls as smooth as butter. I took the exhaust off and tried and the plug in and the same result with resistance. Plug off and no exhaust, pulls smooth. It doesn't appear that there is anything blocking the clutch bell and the clutch bell turns freely until the spark plug is in, then you can't get a smooth rotation. The spring appears to be fine with no obvious breaks. The flywheel and fins look good and no breaks seem to be evident.

I checked the drive drain and everything is working and there doesn't seem to be anything binding up anywhere.

 

[Ice_2k]

it's normal to be more difficult to spin the engine with the plug on and it's also normal to fill some "lumps" when pulling

 

[talunceford]

Ok I took the motor back out and try to start it with the plug in and exhaust on. When I pulled the rope it did pull BUT it was really jerky or rigid, not a smooth pull at all...if that makes sense. I pull the plug out and it pulls as smooth as butter. I took the exhaust off and tried and the plug in and the same result with resistance. Plug off and no exhaust, pulls smooth. It doesn't appear that there is anything blocking the clutch bell and the clutch bell turns freely until the spark plug is in, then you can't get a smooth rotation. The spring appears to be fine with no obvious breaks. The flywheel and fins look good and no breaks seem to be evident. I checked the drive drain and everything is working and there doesn't seem to be anything binding up anywhere.

Yeah, with the plug out, there isn't any compression. Which will make it REALLY easy to pull. If you don't have compression, your engine won't run or won't run very well.

Here is an explanation of how the 2stroke engines work.

 

[Rusty Nail]

I guess what I'm saying is it's not locked like before but I still cant get a good pull to start it. There still seems to be way to much resistance to get a good pull to try and start it. I guess I will take it to the small engine repair guy in town. I hear he is pretty good at small motor issues.

 

[Rusty Nail]

Thanks for the video.

After watching the video it almost seems to be something wrong with the compression. Thanks again for helping a newb out.

 

[talunceford]

I guess what I'm saying is it's not locked like before but I still cant get a good pull to start it. There still seems to be way to much resistance to get a good pull to try and start it. I guess I will take it to the small engine repair guy in town. I hear he is pretty good at small motor issues.

Hmm.... might be a bearing issue then. As in crankshaft bearing. Just a guess though. Now, if you were to take the pull start off, can you turn the flywheel by hand with the plug in the head?

 

[Rusty Nail]

I can turn the flywheel by hand with the spark plug in when the fly wheel is off. It's weird because originally I couldn't pull or turn anything until I took the motor out the first time. Now that I've had it out and messed around with taking the plug out and putting back in and trying to start it, it's not LOCKED anymore like it started out.

I also noticed the negative black lead looks like it was pinched at the factory and has a cut on it. I don't think that has any affect on what's going on now but I guess it could have caused it to die and hard to start back.

 

[alfred e numan]

its hard to see if anything is wrong via words. my engines turn over easy with no plug. when the gas- oil mix is in the engine, the compression increases. With my xb- its a light car-- when the engines primed up with gas, i can actually lift the car off the ground with the pull starter. I always use a homemade stand to get all 4 tires off the ground, brace the car with one knee-- then pull the starter cord. when i say lift the car off the ground-- its hanging in the air-- but the motor is not turning over.-- these hobby engines have compression ratios approaching 17 to1. !!!

 

[talunceford]

I can turn the flywheel by hand with the spark plug in when the fly wheel is off. I guess it could be the fly wheel. It's weird because originally I couldn't pull or turn anything until I took the motor out the first time. Now that I've had it out and messed around with taking the plug out and putting back in and trying to start it, it's not LOCKED anymore like it started out. I also noticed the negative black lead looks like it was pinched at the factory and has a cut on it. I don't think that has any affect on what's going on now but I guess it could have caused it to die and hard to start back.

One thing to check is the gap between the coil and the flywheel. The screws that hold the coil on the head, loosen them up. Take a business card or something about the same thickness and place that between the flywheel and the coil. Rotate the flywheel until the magnet on the flywheel is in the same position as the coil. It will suck the coil down to the flywheel. You need the card between the flywheel and the coil to create the gap. That gap is what causes the coil to generate a spark. If for some reason that gap closed or is close enough to the flywheel to prevent it from turning, that might be your problem. A improperly gapped coil will cause the spark to be weak or to not generate a spark at all. I had to re-gap my coil on my factory 30.5 and I think it improved the performance some. I got that instruction from Dan at OBR. Try that.

 

[Rusty Nail]

I will check that when I get back home. Thanks again guys...I'll figure it out with you alls help ...that what I like about the hobby...trial and error...sometimes more error!

 

[Rusty Nail]

One thing to check is the gap between the coil and the flywheel. The screws that hold the coil on the head, loosen them up. Take a business card or something about the same thickness and place that between the flywheel and the coil. Rotate the flywheel until the magnet on the flywheel is in the same position as the coil. It will suck the coil down to the flywheel. You need the card between the flywheel and the coil to create the gap. That gap is what causes the coil to generate a spark. If for some reason that gap closed or is close enough to the flywheel to prevent it from turning, that might be your problem. A improperly gapped coil will cause the spark to be weak or to not generate a spark at all. I had to re-gap my coil on my factory 30.5 and I think it improved the performance some. I got that instruction from Dan at OBR. Try that.

I did what you suggested and the gap did indeed close with the business card in between the flywheel and the coil. Di you email Dan at OBR. I couldn't find the instructions on their website.

 

[talunceford]

I did what you suggested and the gap did indeed close with the business card in between the flywheel and the coil. Di you email Dan at OBR. I couldn't find the instructions on their website.

I believe I saw it on one of the videos that he had on rebuilding an engine.

 

[talunceford]

I did what you suggested and the gap did indeed close with the business card in between the flywheel and the coil. Di you email Dan at OBR. I couldn't find the instructions on their website.

So was it further apart or had it closed all the way before you used the card?

 

[talunceford]

I did what you suggested and the gap did indeed close with the business card in between the flywheel and the coil. Di you email Dan at OBR. I couldn't find the instructions on their website.

Watch this

He talks about it here.