New to pro (stihl) saws NOT A GOOD START!

[drcolfelt]

Hey everyone!

I am new here so sorry for the long story! I am not by any means a arborist! But totally respect and envy the skills that you guys have! Here goes my long problems.

So i am a automotive technician and decided to buy my first pro grade chainsaw. It was a used MS250 thast i purchased from a private party for $250. Then the problems started... I took the saw out on my property and after a fresh tank of 50:1 (stihl hp) and some bar and chain oil (pollen (sorry guys), i tensioned the chain and got to work. Then, after about 5 minutes the saw started to bog down and smoke came from the chain catcher area. I have some small engine experience (not a lot!) so i decided to investigate. The chain had gotten hot (even a bit of blue on the bar). My initial thought was that it was just a lack of oil supply to the bar, but as i investigated i found that the case of the saw had gotten so hot (around the chain brake) that it had even melted a bit. I disassembled the saw further and found some more damage, i ended up replacing the oil worm gear, clutch drum, clutch bearing, fuel line, fuel filter, impulse line, air filter and doing a full teardown of the saw and cleaning everything and even removing the piston! The saw was missing the clutch bearing, and i thought that was the reason for the overheating. Also the saw got so hot that the plastic from the worm gear melted.


SOOOOO.. today i got the saw all the way back together and it runs great but the clutch area still gets hot after running the saw for even a minute or two, it is getting oil but after i run the saw some leaks out of the bar. It does seem to be getting good oil flow.

Here are my questions-

How hot is the clutch supposed to get?
Is a small puddle of oil supposed to leak out around the chain adjustment area after running the saw?
What could cause the over heating problem?

Please let me know if you need anymore info!! Thanks so much!

 

[rwoods]

Sorry to be the one to break the news to you, but Stihl markets three grades of saw: Homeowner Farm&Ranch Professional. The MS 250 is marketed as a homeowner saw. Not saying that justifies a problem. Ron

 

[7sleeper]

Stihl 250 is no pro saw!

7

 

[drcolfelt]

I knew that was coming, I am aware that it a a homeowner saw, it is more pro to me then most saws ( poulan, remington, homelite ect..)
I apologize for the misrepresentation!

 

[rwoods]

Chain getting hot among other things may indicate a dull chain. Runs slow then chain is too tight. Clutch can be getting hot from either of these. Did you check the chain brake when you had it apart? Ron

 

[rwoods]

No clutch bearing and metal to metal contact will heat things pretty quickly. Did the clutch drum turn freely when you replaced the bearing? Was the crank shaft scored? Ron

 

[drcolfelt]

Yes when the saw was apart i checked the operation of the chain brake and it was OK, i sanded it with 120 grit abrasive as the stihl repair manual specified. It gets hot even when not cutting, just running the saw on the bench ( i am assuming that would eliminate the thought of the heat being caused by a dull chain). I also tried putting some more slack in the chain thinking it was too tight. I am at a loss!

 

[drcolfelt]

The crankshaft was not scored, the new bearing slid over the crank very smoothly, and it does spin freely. Thanks for the fast reply!

 

[rwoods]

A clutch will get too hot to touch ordinarily, but I am assuming yours is getting really hot. Hopefully someone who knows more than me will come along and help you. Ron

 

[drcolfelt]

Yes it does get quite hot Thanks for your help Ron!

 

[rarefish383]

Welcome to the site neighbor, I'm right down the road in Mt Airy. Sorry, no answers to your questions, I run mostly 40 year old Homelites, when they were pro saws. About 6 or 8 years ago I needed a small saw so I bought an MS290 new from Southern States and it has performed flawlessly. I'm not a small engine mechanic, but I have been around chaisaws since day 1. If you don't get an answer, I'd be happy to take a look, but I'm really tied up for the next 2 or 3 weekends. Good luck, Joe.

 

[cutforfun]

how does the chain rotate around the bar by hand. Make sure the chain pitch matches the sprocket on the saw

 

[drcolfelt]

wow rarefish you are close! I go to Century Ford on Twin Arch Rd from time to time to pick up parts. If I cant figure this thing out i may have to take you up on that offer, I am getting so frustrated. Cutforfun the chain goes around the bar smoothly, and the chain and clutch sproket are both .325. Thanks again everyone!

 

[SteveH]

No clutch bearing. You got taken on this one. But live and learn. Without having the saw at hand, tough to say exactly what all is going wrong. But no way the saw should have those heat problems. I run three Stihls at present, frequently, never had those problems. Hopefully, you'll get it running right and this is a learning experience. Hope it wasn't a friend who sold it to you. For $250, you shoulda had yourself a decent-running 250.

 

[drcolfelt]

Steve,

I sure did! At least it was not a friend, it was friend of a coworker, still pisses me off! I did however learn how to tear down and reassemble this saw. If I cant figure it out within the next few days I may take it to the local dealer and let them have a look.

David

 

[john_bud]

Make sure the oil ports in the bar are open. Then ensure the bar groove is clean.

Double check at the bar mfg site that it is the correct one for the saw.

 

[Locust Cutter]

Does that saw have a filter on the oil pickup tube? If so, did you replace that as well? That wouldn't affect your clutch, but it would affect the bar /chain as would the oil ports in the bar being clogged up. As far as the clutch being warm, when you take the bar/chain and clutch cover off, does the clutch hub rotate freely around the clutch shoes or is there a "catch" at any point in the rotation? If there is a friction spot anywhere that could be causing a partial slippage of the clutch, or if one of the shoes isn't spinning outwards under throttle, that would cause major problems and heat buildup in short order... For all of the years that Dad and I ran his old 039, the only problem we ever had (other than a consistently dirty air filter) was when the oil pickup filter got plugged from debris entering the tank during top-offs. We're much more careful now to clean off the filler area before topping off our saws.

 

[fearofpavement]

There are three primary reasons for the clutch to heat up. One of them is your problem

1. The bearing is dry and generating heat. This bearing is primarily spinning when the chain is not moving.

2. The clutch housing is contacting the chain brake band. Either because the chain brake is engaged or the routing on the band is incorrect. ie, the band may be out of position. This heat would occur when the chain is moving.

3. The clutch is slipping against the sprocket drum. Sometimes weak clutch springs will cause the shoes to contact the drum at idle but that usually results in the chain constantly moving.

One other reason a clutch can get hot is if the chain and bar are hot. They will transfer the heat to the clutch area. It seems you already eliminated this as a possibility.

The damage you initially described is consistent with the saw being operated with the chain brake engaged. Not saying that is what happened but that is the type of result you would see.

go from there.

 

[stipes]

There are three primary reasons for the clutch to heat up. One of them is your problem

1. The bearing is dry and generating heat. This bearing is primarily spinning when the chain is not moving.

2. The clutch housing is contacting the chain brake band. Either because the chain brake is engaged or the routing on the band is incorrect. ie, the band may be out of position. This heat would occur when the chain is moving.

3. The clutch is slipping against the sprocket drum. Sometimes weak clutch springs will cause the shoes to contact the drum at idle but that usually results in the chain constantly moving.

One other reason a clutch can get hot is if the chain and bar are hot. They will transfer the heat to the clutch area. It seems you already eliminated this as a possibility.

The damage you initially described is consistent with the saw being operated with the chain brake engaged. Not saying that is what happened but that is the type of result you would see.

go from there.

Im with you on #1 and 2. Its getting friction from some area, but where. My thoughts are towards the brake band.

 

[tree monkey]

since the saw was ran without a clutch bearing, the clutch drum has rubed a hole in the case, this is your oil leak and lack of oil going to the bar/chain. you will need a new case.
you should not have paid more then $50 for that saw