Question on Symptoms of Seal Leaks

[Clarkbug]

Mornin' All.

So question about when a seal is leaking on a saw, or I guess more appropriately, when do the symptoms typically show up?

A few years back I bought an 028 Super that was pretty rough, but the price was right. With some help here I got it pulled apart and put back together with a new piston, since the old one was toast. I figured it was probably carbon scoring at the time based on the condition of the combustion chamber and exhaust port.

Now when I run it, the saw starts and runs great through the first tank of fuel or so. After that, it starts acting strange, wanting to die out when you set it down or tip it on its side.

My thought is that after some heat in the cases and crank, there could be a gap opening up on the seal somewhere. But is this common, or should I look elsewhere first?

I am not set up to pressure/vac test, so trying to rule out other possibilities first. If I do have to go that route, not sure of the best way to block the intake and still leave access to the impulse line to pull a vacuum on. Any thoughts there?

 

[sefh3]

Usually the signs of air leaks are higher reving or leaning out at wot. Have you checked your fuel line to make sure you have no cracks in it?

 

[Clarkbug]

I havent. I did put a new line in it when I put it back together, but I realize that might not mean anything. If I get a chance Ill pull the line to see how it looks.

 

[lone wolf]

Sounds like it is time to learn how to do the vac test. It will save time in the long run.

 

[struggle]

If you lay the saw on its side and it dies or revs up in short that is an indication of leaking seals. If it die on one side the fuel seals the seal and it stalls. It it runs fast on the other side then it sucks air on the top side seal.

Like mentioned the best way to tell is to vac test and pressure test and spray the saw areas down with soapy water while pressure testing at say 5 psi. It will show almost immediately your problem.

You could also have a cracked intake boot if idle changes while loading the handle when the a/v mounts move around or fuel line pin hole leak.

 

[Clarkbug]

Thanks all.

I just wasnt sure if it could be a different problem since it only seems to show up after I have put some run time on the saw.

Guess its a good thing I got those tools from watsonr on the group buy, sounds like Ill need them!