Another ps5100 thread lol

[wyk]

The ring will need to reseat before you'll get max compression.

Yup. When I recently replaced the barrel and piston on the 046, I could start it without the decomp without too much problem - not easy, but it would work. Now I risk cutting off a leg if I do it that way with a drop start after 20 or so tanks, the compression's gone mad. If I REALLY give it a go without the decomp, it will start, but that's got to be tough on the whole starter assembly. So run her easy so she sets and see what she reads. I was told to run it in smaller wood for 15-20 mins, let her set for 20-30 mins, and repeat for a couple of tanks, and let her warm up slowly.

 

[ktoom]

Well i fired the old girl up today and used it for 5 mins. Im gonna use it some more this week so maybe the ring will seat with the cleaned up cylinder. She ran great, but when i shut it off the carb was making a weird noise. It sounded like the gas tank wasn't venting properly. Is this a common thing with these saws? My 6401 sorta does the same thing.

 

[rms61moparman]

Run what'cha got 'til it blows!
That will give you several years to figure out what you want to do.
I've cleaned up several pistons worse than that and have yet to have a problem.
A lot of the mechanics on this site are better than they really need to be.
Richen up your mixture and run the doggie doo out of it, it will be fine.
Does your carb still have the little foam ring on it? toss that and seal off the hole in the filter.


Mike

 

[ktoom]

Thanks for the info Mike. I was thinking the same thing, run here till she blows. Besides I got a brand new 5100 for back up hahahahaha.Before I fired her up I gave the H screw half a turn. Once I get my new tach, I will see where she tops out at. The foam is still on the carb, so I will rip it off and plug the filter hole. Will that stop the weird venting noises I was hearing?

 

[rms61moparman]

If it doesn't, crack the gas cap when you are hearing it and see if it stops.
That could be several things from vent issues to heat issues to ethanol gas issues.
Diagnosing it will be a "hunt and peck" scenario.


Mike

 

[Andyshine77]

I've had this happen with my 7900's when they cool, the tank forms a vacuum and starts sucking in a bit of air, it's normal.

 

[ktoom]

When i got home today, i checked the cold compression and it red 190psi. I did it a second time and got 180psi.

 

[Andyshine77]

Most compression gauges are somewhat inaccurate.

 

[ktoom]

Yup, gotta love it hahaha. Its so funny cuz im like did i push the release valve when i was pulling it over..... then i thought about it and im like nope this things just inaccurate.