Won't start sometimes

lordoflightaz

lordoflightaz

New Member
Just when I thought I had it all worked out.

Still breaking in the engine on 2nd tank of gas at 16:1 mix. so just over 100 miles on the engine. I get on the bike pedal for a bit to get some speed so I don't fall over, let out the clutch and push down on the pedal at the top of the arc. pedal does not move. If I weighed more maybe I could get it to work. It is like the piston is locked up.

Bike has shift kit on it so that makes it a little complicated.

To get it to start I release the clutch and bounce/roll the bike backwards a few times and finally the piston starts going up and down. Initially it is locked tighter than a drum.

Took off the top end inspected the cylinder walls there is no scoring it looks okay to me, but what do I know. Neighbor says maybe I should use Castrol 2T oil instead of the stuff I am using Ace Hardware 2 stroke.

How long would I have to just run the engine to finish a break in, if that is the issue? Would 7 hours with breaks for cool down seem about right?

I think with the kit still in place I could put on a left rear sprocket on and attach it to the drive sprocket for another 100 miles until the engine is broke in I really don't want to do this.
 
Sounds to me like your engine is getting broke in and building more compression you might want to go to 32 to 1 mix. other than its hard to start is it running good?
Norman
 
If you are using a shift kit, make sure you are not in a lower gear (like 1st) to start it, that would make it very difficult to turn over.
 
Norman, If I take the plug out, the piston still is stuck in place. For a rawusa is runs good somewhere near WOT it is not so great compared to my other motor.

Joe, I put it in 1st or 2nd to start. In the beginnig I did that a few times Anything past 3rd and I can't put enough weight to spin the pedals at all.
 
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with the plug out you still can't get it to turn over easy?! something is wrong! that don't sound good to me take off the exhaust pipe look inside there and see if you can see any galling/scratches also you should be able to see the piston look for scratches there as well you can see the piston on the intake side as well you might have one going bad. another thing is some of these engines have bolted on flywheel weights and one side might of come loose you got to have something binding or hanging up check under all of your engine covers for loose nut or rubbing parts.
 
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Norman said:
with the plug out you still can't get it to turn over easy?! something is wrong! that don't sound good to me take off the exhaust pipe look inside there and see if you can see any galling/scratches also you should be able to see the piston look for scratches there as well you can see the piston on the intake side as well you might have one going bad. another thing is some of these engines have bolted on flywheel weights and one side might of come loose you got to have something binds or hanging up check under all of your engine covers for loose nut or rubbing parts.
Click to expand...

I did take of the top end and looked no scoring, looked at magneto side and clutch side with out taking either out nothing seems out of place or bits of metal.
 
The next time when it is "locked up" take off the clutch actuator and look behind it to see if the chain is "balled up" around the little sprocket of the engine. Could be chain is too loose. Walter F.
 
Not a bad idea to remove the jackshaft and run it in the stock configuration for a little bit just to ensure that the problem is entirely engine related and not drive train related. Should be simple to accomplish without even taking the engine off. Pull the left bearing plate, remove the jackshaft, run your standard chain to the left side rear sprocket and give it a shot. Definitely sounds engine related to me though.
 
yea the chain if run too loose can cause it to bind up right around the front sprocket. I was going on the idea that the engine is acting up. all components have to work together and one simple thing over looked can rear up its ugly head and bite you.
norman
 
Well, I know that the chain is not getting messed up. I can see that without taking things apart, with clutch in, all 3 chains move freely.

Could the 16:1 mixture be gumming it up, I could drain the tank and go up in ratio with another motor oil.

Ghost, the bike has never been anything but a jackshaft equipped system. So simply taking off the left bearing plate is not a trivial thing. LOL. I have to find a chain the right length, install a sprocket, chain tensioner and chain guard.
 
I think what Ghost0 was saying was to just remove the shaft and leave the rest there. I just looked at my bike and it's very doable. I guess you would need a new chain but that's not a big deal.
I hate like heck to disagree with the guy who makes and sells the shaft kits ( no offence meant Ghost0) but I find it easier to start in first gear. I also find it better to have my feet in motion and just as I reach the one o'clock position with my right leg, I pop the clutch and it starts by the time my foot reaches the bottom. I'm so lucky!
Not sure of how to word it but I think what takes getting used to is the fact that it takes a lot of force to get it moving but once it starts to move, you are OK. There are times when my clutch slips and I have to re-do the start attempt.
I'd go with a good synythetic 2-stroke oil like Amsoil and use a little less oil.
 
toytime, there iis no way I would disagree with Ghost on his kit. I was just mentioning the bike has always been a "shifting maniac" So some work is involved, not a big deal.

On starting, prior to this lock up, All I did was stand on the pedal at 1 or 11 and let out the clutch and step down. It it didn't start I would back pedal and step down again. Never more than 3 time and the bike would start, unless I was above 3rd gear.

Yesterday, the bike started 3 times with no issues, but I am backing it up in gear when I stop it to make sure that the piston is not locked up when I stop.
 
Just so you know, I was referring to myself when I said that. I just think starting (for me) works better in first gear, that's all.
 
Same thing happening today. Present solution is do the "backup bop" once before I even think about starting. If it does not move the piston, then I bop a few more times till the piston moves. Then every thing is fine. I am going to run through this tank of gas and then try it with about a 25:1 mix. If I screw up the motor I have another, which is a story in and of itself.

Toytime if I weighed more I would do what you do as well. Hard to believe 2 years ago, I just rode my bike without a motor.
 
I agree installing the stock drive system is not a trivial matter but I guess I was just saying that to do it would not require a complete disassembly of the shift kit or removal of the engine, so that wouldn't be the time consuming part. Installing the left side sprocket now that is the time consuming part.

You definitely have an odd engine issue. Sounds more than just fuel/oil related. But it might be.
 
Well it locked up again last night at the bar. No bump and bop would get it to move the piston. Pedaled home, without the shift kit pedaling sucks so I am glad that I had not changed to a rear sprocket yet. I put a sprocket on a rim Friday night but hadn't started the conversion back. When I got home I took off the top end and made some attempts to move the piston, with no luck. I sprayed WD40 in it and let it sit overnight checked on it this morning and surprise surprise the piston moves again.

It seems fairly obvious even to my simple mind that something is gumming up the cylinder wall. I am going to try running at a 32:1 fuel mix with Castrol 2T and see if that corrects the problem.

I sure would rather be working on a project that figuring this out.
 
Switched to 32:1 mix with Castrol 2T. Boy that is some pretty blue oil, reminds me of Aqua Velva .Also changed spark plug, for no good reason. Took the bike 3 miles. Stopped, left fuel on, let it rest about 10 minutes. Started it up and ran 1 mile. Stopped, left fuel on, let it rest about 10 minutes. Started it up and ran 2 blocks Stopped, left fuel on, let it rest about 20 minutes. Started it up and ran 2 blocks Stopped, left fuel on, let it rest about an hour. Started right up. Now it is resting in the garage and I probably will take it on a short run tonight and see if it starts.
 
Another day with no issues. I made a lot of stops yesterday.

Of note: I used the same fuel, only the brand of oil and mix ratio changed. Also, the engine starts a bit easier, I am able to "pedal through" rather than rewind and pump down to start. Could be that I don't have as much compression with all that gunk off the cylinder.
 
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