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036 pro rpm?

made_of_stihl

made_of_stihl

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I have an 036 pro that runs fine. Bought a tach to check rpm and help tune. It read 15k rpm wot, is that possible? Checked same on my 038 super and read around 12.6k rpm. It has limit tabs on carb, so I cut the tab on the high adjustment, but could only get it to back down on 14k range before I couldn’t turn the screw anymore (and it didn’t sound right). Any thoughts?
 
Ryan'smilling

Ryan'smilling

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Sounds a little too high at 15k. 14 would be a little more reasonable, but still pretty high. 13-13.5 is probably safe, but I don't know what it says in the manual. More important is that it responds to adjustments, which is sounds like it does (to some extent anyway) and that it 4-strokes at WOT. If you don't hear 4-stroking, check for air leaks. My 036 started screaming recently, and had a hole in the impulse line.
 
windthrown

windthrown

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036 max revs in the book is 13,500 rpm. But there is a 10% engineering margin built into that number for safety, so the real red-line is 14,850 RPM. So you should be OK with that. But I would check for a leak in the air intake.
 
made_of_stihl

made_of_stihl

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I should have mentioned something else. I tuned the LA and low setting at the beginning of the day. Periodically I set saw down to do something else, and the idle speed would change. Sometimes I’d hear it change and look over and the chain would be running, or I’d hear it slow down suddenly. Could this be related to impulse line or intake mentioned above regarding high RPM? Thanks again.
 
Ryan'smilling

Ryan'smilling

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I should have mentioned something else. I tuned the LA and low setting at the beginning of the day. Periodically I set saw down to do something else, and the idle speed would change. Sometimes I’d hear it change and look over and the chain would be running, or I’d hear it slow down suddenly. Could this be related to impulse line or intake mentioned above regarding high RPM? Thanks again.

Could be. Could also be a fuel filter, air filter, or carb issue. But based on the symptoms you describe, I would refrain from using it until you investigate further.
 
made_of_stihl

made_of_stihl

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So I was able to get this saw apart this afternoon. The impulse line did not appear to have a hole. Idk if this makes sense, but where the line attaches to the motor, it spins but does not slide off. I didn’t force it off, but curious what type of connection this is. Also checked intake boot. Didn’t seem to have any holes. Only thing I noticed wrong is gas cap doesn’t seal properly and gas leaks from it. Anyone have any suggestions on how to move forward?
 

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trains

trains

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Its a small brass barb that the impulse hose attaches to the case, if its just swiveling on that barb, its gone hard, and would be at least one area of possible air leak that would give such a high rpm.

if that hose has hardened, I would also go and replace the fuel hose, and do the crank seals whilst I am at it, then your good for many years to come.

Heat the hose, and gently pry off with a flat head screw driver.
Have a very close look at the intake boot as well, if its going hard, time to replace as well.
If not already mentioned, worth putting a carb kit and fuel filter whilst your at it too.
 
made_of_stihl

made_of_stihl

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Its a small brass barb that the impulse hose attaches to the case, if its just swiveling on that barb, its gone hard, and would be at least one area of possible air leak that would give such a high rpm.

if that hose has hardened, I would also go and replace the fuel hose, and do the crank seals whilst I am at it, then your good for many years to come.

Heat the hose, and gently pry off with a flat head screw driver.
Have a very close look at the intake boot as well, if its going hard, time to replace as well.
If not already mentioned, worth putting a carb kit and fuel filter whilst your at it too.
Thank you trains. Any vid on doing crank seals? Never done that. Also where’s best place to get all these parts? Appreciate your help.
 
windthrown

windthrown

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I would also check that the carb is on there nice a tight. If they get loose, they can suck in more air into the intake. Funny saw revs can also come from a leak in the gas line. Check the fuel filter and replace the gas line. They are cheap enough, and they tend to crack in time and any leaks in the gas line can give you all kinds of weird symptoms and failures.
 
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