Stihl MS360 bent bar???

[spencer]

Ive just changed the 20" bar and chain on my Stihl MS360 cause it was getting red hot and cutting badly- (must be bent I thought). BUT the new on ive put on does just the same. The chain gets oiled and does cut normally this time but the sprocket/bar/clutch area is too hot to touch...any ideas why anyone..
thanks
spencer

[beenthere]

I assume you know that the sprocket and the chain are matched for each other.

Otherwise, I always change the sprocket whenever I add new chain. I alternate between two new chains until both are worn out due to sharpening or mishap, and then put on a new sprocket with two new chains to start the cycle over. An old sprocket with a new chain will wear one or both until the chain and sprocket match each other. Getting that match will cause heat and wear.
Not sure if this is what is happening to you, but sure sounds like it could be the problem. ??

[spencer]

Thanks....I`ll change the sprocket and see if it does the trick...

[Kevin]

Check the brake band also, it might be rubbing on the clutch.
The needle bearing is probably cooked as well.

[jokers]

Hi Spencer, how old was the bar that you replaced? The suggestions that the other guys have made are all good but the issue may be with the bar itself. I`m guessing that both bars could be the laminated ones that Stihl is sliding by on alot of folks and they are not very good, or atleast alot of people are having trouble with them. The rails are too tight and the sprocket noses seem to be prone to seizing and the heck of it is that none of them have a hole to grease the tip. Sometimes with alot of perserverance you can use the bar until it wears in but other times you won`t be so lucky.
BTW, how are you sure that the chain is being oiled normally? Are you sure that the bar groove isn`t full of impacted sawdust, it can suck up alot of oil. Another thing, are you sure that you have the same gauge bar and chain and everything is the right pitch including the sprocket nose? How tight do you run your chain? Is your chain sharp, dull chain generates alot of heat. Just a few ideas to consider. I would appreciate having you bring us up to date when you solve this mystery as long as it doesn`t turn out to be something too embarassing.  

Russ

[spencer]

The bar is a brand new stihl rollomatic E . I know everything is the same pitch as the bar, sprocket and chain all have 3/8 stamped on them (there also stihl).
The bar has had little use and will get red hot when just revving the saw for a few minutes. I could also tell the chain is oiled as it  throws oil off the bar end and I could see a thick film of oil on the tangs after use..
Changing the rim sprocket on the clutch drum may cure the problem as this has some wear. other than that the only other thing I can think of is the new bar was warped to start with -  but I`m sure thats pretty rare?.

[Kevin]

Be sure to check that needle bearing under the clutch drum.
Is there a chance that you might be over tensioning the chain?