Did you check the inside of your muffler,maybe there is a baffle when hot that moves and block outlet holes somewhere.Does this saw has or had heated grips (dont laugh ) on it?When the engine is losing rpm,does she begin to four stroke or she runs like starving for fuel to keep the"right exhaust note" ? Do you run it with a felt filter ? I dont think you have an air leak because she will be leaning out.
Help with 372XP
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lesorubcheek
Addicted to ArboristSite
Jim,
I have to assume this is a subtle problem, otherwise a reasonable shop would have found what's wrong already. Does the saw behave this way consistantly and from the very first cut, or will it run normally for a short period and then begin to act this way? It sounds like the saw is running normally in a no-load condition... is this true? I assume this is the case since the comment was made the problem occurs in the cut. My guess is a fuel starvation problem and it could be as simple as a vent for the fuel tank. Not familiar with details of a 372, but I'm sure somewhere there's a fuel tank vent. Other's suggestions for checking the fuel line and filter also make sense. I have to assume when the carb was rebuilt that it was cleaned properly so the problem shouldn't be there, but you never know.
Good luck,
Dan
I have to assume this is a subtle problem, otherwise a reasonable shop would have found what's wrong already. Does the saw behave this way consistantly and from the very first cut, or will it run normally for a short period and then begin to act this way? It sounds like the saw is running normally in a no-load condition... is this true? I assume this is the case since the comment was made the problem occurs in the cut. My guess is a fuel starvation problem and it could be as simple as a vent for the fuel tank. Not familiar with details of a 372, but I'm sure somewhere there's a fuel tank vent. Other's suggestions for checking the fuel line and filter also make sense. I have to assume when the carb was rebuilt that it was cleaned properly so the problem shouldn't be there, but you never know.
Good luck,
Dan
manual
Addicted to ArboristSite
I'm confused was this saw modded?
Between reading this and the little woman talking in my ear I got lost.
Between reading this and the little woman talking in my ear I got lost.
TJACK
ArboristSite Lurker
I will try to answer eveyone's question and clear up a few things.
The only thing modified on the saw is the exhaust. This is minor and has been checked out (nothing rattles).
The crank was replaced as an assembly with a bearing and rod in a new case. The seal came with it already together in the case. There was no change after this was put in. I think this rules out the air leak in the seal crank area
The problem is subtle? Yes, if you are running the saw without muffs it is more difficult to detect, although I can hear it and feel it and so could the last guy working on it. Subtle yet consistant. What I mean is it happens every time I run the saw within minutes. It will begin normal then start to act up.
Lets say you are humming, then change your hum a few octives lower, then it goes back to the original hum, then back down a few octives back and forth. All along, the thickness of the log is the same, no change in down pressure on the saw and no change in throttle position!
I am still not sure if a pressure vac test was performed, so I will call my local dealer to see if he can do it. The last time I had the saw to him all he did was play with the carb adjustments.
We have checked the fuel tank vent and looked for a kink in the fuel line, all seem OK.
Thanks to all who have offered their thoughts, Any more?
Jim
The only thing modified on the saw is the exhaust. This is minor and has been checked out (nothing rattles).
The crank was replaced as an assembly with a bearing and rod in a new case. The seal came with it already together in the case. There was no change after this was put in. I think this rules out the air leak in the seal crank area
The problem is subtle? Yes, if you are running the saw without muffs it is more difficult to detect, although I can hear it and feel it and so could the last guy working on it. Subtle yet consistant. What I mean is it happens every time I run the saw within minutes. It will begin normal then start to act up.
Lets say you are humming, then change your hum a few octives lower, then it goes back to the original hum, then back down a few octives back and forth. All along, the thickness of the log is the same, no change in down pressure on the saw and no change in throttle position!
I am still not sure if a pressure vac test was performed, so I will call my local dealer to see if he can do it. The last time I had the saw to him all he did was play with the carb adjustments.
We have checked the fuel tank vent and looked for a kink in the fuel line, all seem OK.
Thanks to all who have offered their thoughts, Any more?
Jim
klickitatsacket
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Reading through this I would agree that it sounds like fuel and from your description it is heat related expansion. I would really look over the areas between the carburetor and the cylinder, with particular attention paid to the impulse feed. Make sure the holes are clear of any partial obstructions. You might have a hole not drilled out all the way as well. When the saw warms up it might be causing a partial obstruction and cutting the amout of fuel being delivered.
Big Woody
ArboristSite Operative
Seems Like PA fits the description. I have seen Dozer Dud (according to B Walker) selling on ebay and he was a modder on this site. His ebay address was PA if i remember correctly.
Do I win the saw?
Justsaws
Addicted to ArboristSite
"The problem is subtle? Yes, if you are running the saw without muffs it is more difficult to detect, although I can hear it and feel it and so could the last guy working on it. Subtle yet consistant. What I mean is it happens every time I run the saw within minutes. It will begin normal then start to act up.
Lets say you are humming, then change your hum a few octives lower, then it goes back to the original hum, then back down a few octives back and forth. All along, the thickness of the log is the same, no change in down pressure on the saw and no change in throttle position!
We have checked the fuel tank vent and looked for a kink in the fuel line, all seem OK."
That sounds as though the engine is not com-busting the fuel which could explain the plug. Play with the sparkplug gap. Gap it down to .016 from.020. Also make sure it is the correct sparkplug and that the coil wire is not grounding out after the saw gets hot. Make sure that the ignition was actually replaced and if so was it new? Was it installed correctly? Check the on/off switch and wire for shorts as well. Look for subtle pinch points that might occur when the saw is in the cut.
If the carb was replaced, was it new. Does the choke butterfly flutter? Does the throttle butterfly flutter? After you turn it off does the muffler smoke and smell strongly of fuel mix? Run it with the gas cap loose as was suggested. If it is getting rich and lower in tone you are looking for spark or fuel issues most likely.
Hope this helps and you get your saw fixed. Good luck.
Lets say you are humming, then change your hum a few octives lower, then it goes back to the original hum, then back down a few octives back and forth. All along, the thickness of the log is the same, no change in down pressure on the saw and no change in throttle position!
We have checked the fuel tank vent and looked for a kink in the fuel line, all seem OK."
That sounds as though the engine is not com-busting the fuel which could explain the plug. Play with the sparkplug gap. Gap it down to .016 from.020. Also make sure it is the correct sparkplug and that the coil wire is not grounding out after the saw gets hot. Make sure that the ignition was actually replaced and if so was it new? Was it installed correctly? Check the on/off switch and wire for shorts as well. Look for subtle pinch points that might occur when the saw is in the cut.
If the carb was replaced, was it new. Does the choke butterfly flutter? Does the throttle butterfly flutter? After you turn it off does the muffler smoke and smell strongly of fuel mix? Run it with the gas cap loose as was suggested. If it is getting rich and lower in tone you are looking for spark or fuel issues most likely.
Hope this helps and you get your saw fixed. Good luck.
Grande Dog
ArboristSite.com Sponsor
Take a cold compression test and then when it gets hot and lazy, get another test as quick as you can.
PetrolHead
ArboristSite Operative
bump_r said:
Myself, I can't help the bloke because I really don't know. But I had this symptom with my Husky when it was new. Had a nice long red gum one day and it almost drove me mad, blubber-smooth-blubber-smooth-blubber-smooth, almost rhythmic. Still does it once in a while now but usually when the chain is getting dull and/or the wood is very hard. The problem started to go away when I learnt to tune the saw better, learnt what a sharp chain was and I think the saw I have is just a bit prone to it anyway. Again, I'm not giving any advice here because I really don't know, just an interesting thought.
TJACK
ArboristSite Lurker
Well, the saw has been taken to a Stihl dealer who just recently got away from selling Husky saws (was a Stihl & Husky dealer for 15 + years). They can do the vac and pressure test and have vowed to find the problem. I will let everyone know as soon as I get the saw back. Better yet, I will not take the saw back until we run through some testing.
Thanks for all of your replys,
Jim
Thanks for all of your replys,
Jim
TJACK
ArboristSite Lurker
372XP Problem Update
Well, I just got the saw back from another saw shop. They said the compression vac test showed the saw was fine so they looked it over. What they did was change the fuel line, fuel filter, plug plus a so called tune up, all for the super low price of $49.00. We tried the saw and it is no better then before. Their comment is the difference in pitch or sound is normal, as a matter of fact they said if you took a new 660 or 460 off the shelf it will do the same thing. My response, it is funny that my 357XP and 026 don't do it. Well the big saws are a little different. This is the first "big saw" I have owned so maybe I have been clueless the entire time and the saw is OK.
Given that, does anyone want to buy it? I will assure anyone it is like new! If this is what a 372XP or any other big saw runs like, I will keep the small ones and just send them out for modifications.
Any other thoughts?
Jim
Well, I just got the saw back from another saw shop. They said the compression vac test showed the saw was fine so they looked it over. What they did was change the fuel line, fuel filter, plug plus a so called tune up, all for the super low price of $49.00. We tried the saw and it is no better then before. Their comment is the difference in pitch or sound is normal, as a matter of fact they said if you took a new 660 or 460 off the shelf it will do the same thing. My response, it is funny that my 357XP and 026 don't do it. Well the big saws are a little different. This is the first "big saw" I have owned so maybe I have been clueless the entire time and the saw is OK.
Given that, does anyone want to buy it? I will assure anyone it is like new! If this is what a 372XP or any other big saw runs like, I will keep the small ones and just send them out for modifications.
Any other thoughts?
Jim
Hired Gun
ArboristSite Operative
372
pm sent
pm sent
Justsaws
Addicted to ArboristSite
Sure, post 25 more posts and list it in the correct forum. Hopefully Hired Gun's pm informed you of the rules.
Sorry to hear you are not happy with your 372. Should have been a good saw. Good luck.
Sorry to hear you are not happy with your 372. Should have been a good saw. Good luck.
TJACK
ArboristSite Lurker
Justsaws,
My reply was not intended to be a "For Sale" sign, just expressing some frustration with my saw and giving some feed back to the site members who were kind enough to offer some advice.
Jim
My reply was not intended to be a "For Sale" sign, just expressing some frustration with my saw and giving some feed back to the site members who were kind enough to offer some advice.
Jim
sawinredneck
Addicted to ArboristSite
It's all good, I didn't take it any other way.
Andy
Andy
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