Little rotation on stator shaft

[timbrigham]

My bike - suzuki 81 450 L - recently overheated and died. My fallure, 90-plus degree day and I forgot to check the oil before I left.

I'm getting a click when starting and no attempt to turn over.

I played with it kicking it with some kind of electrical issue, which has been the big thing in the past. Battery look good, the voltage drop when cranking didn't seem too extreme.

I popped the cover off the signal generator, and noticed that the shaft was not spinning freely, just barely when I would get a click. I worked on this before, when I first got the bike and I knew it wasn't right. I spent a little time working it loose with a wrench and afterwards she would start up and run just fine for a minute or two.

Where do I look next?

 

[GregT]

In the oil for pieces of bearing material. Usually small shiny bits....

 

[LAB3]

Looks like you're trying to connect two dots that have no connection! If the engine seized up due to not having enough oil the starter isn't going to be able to crank it over. If you're able to free up the engine and it happens again it's still not an electrical problem. Do what GregT has suggested by draining the oil and looking for metal shavings, they'll look like shiny specs suspended in the oil. Your next best course of action is to run a compression test to see if the engine is damaged, my guess is that it will be. Let us know what the compression numbers are and we can go from there.

 

[timbrigham]

Thanks all.

I checked the oil. Nothing floating, but a few shiny flecks on the oil filter. I checked my trash can and found my last oil filter - it showed similar deposits.

Also checked the compression on both cylinders, just over 60lb each.

 

[LAB3]

Thanks all.

I checked the oil. Nothing floating, but a few shiny flecks on the oil filter. I checked my trash can and found my last oil filter - it showed similar deposits.

Also checked the compression on both cylinders, just over 60lb each.

Sounds like your engine may be shot, it should be in the 150+ lb range for a healthy running machine.

The next thing to do is to put about 10cc worth of oil through the spark plug holes and retest the compression WITHOUT running it first. The extra oil should temporarily fill in any scoring between the cylinder and piston. If the compression goes up significantly, then you need at least a top end rebuild i.e. jugs bored and new pistons. If the compression DOESN'T change much, then it could be one or more valves not sealing. Have you ever tried measuring the valve shim clearances?

Either way it goes, with filings in the oil you're looking at a pricey fix. It might make more sense to start shopping for a replacement engine as opposed to rebuilding the one you have. Then again, with a fresh rebuild you know exactly what you have.

 

[Guest]

Thanks all.

I checked the oil. Nothing floating, but a few shiny flecks on the oil filter. I checked my trash can and found my last oil filter - it showed similar deposits.

Also checked the compression on both cylinders, just over 60lb each.

Did you open the throttle while you were doing the test?

 

[timbrigham]

So, if I opt to purchase a new engine what are my options? Am I constrained by model year, and I go up to a 550, etc. I have some basic cutting and welding skills but I really don't want to have to make any changes to the frame.

 

[LAB3]

So, if I opt to purchase a new engine what are my options? Am I constrained by model year, and I go up to a 550, etc. I have some basic cutting and welding skills but I really don't want to have to make any changes to the frame.

If it where me I'd look for another 450. With the prices of smaller bikes being what they are it would make far more sense to get a bigger bike than trying to cobble in a larger engine.