Diagnostic needed

My 026 is having some issues. I can start it but not with the chain brake on. When it starts, blades and engine run hard until I give gas then it tends to die shortly after. Engaging the chainbrake will stop it altogether. Let me know what you guys think...

 

My old Craftsman does the same thing......interested to learn the causation-

 

You may have an air leak.

 

Clutch drum bearing is shot or needs grease

 

Is this one an expensive fix? I’m leaning towards this as the brake has effect...

 

Not at all, if in fact it is the culprit. Hard to diagnose over the net. It could also have weak clutch springs causing the chain to spin at idle. But in either case, it should still idle, although maybe at slightly lower rpm. Could also be poor carb settings or an air leak

Here's a drum bearing from a member here
New OEM Stihl clutch bearing Chainsaw many models 9512 933 2260 026 036 more 5055485023575 | eBay

 

It could have a bad clutch bearing but I with it dying when he trys to throttle it up, I think it has something else wrong. It could be as simple as a carb adjustment, but how did the carb get out of adjustment enough to where it wont run.

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I think you're right. Now that I read his original post again, he has a little bit more going on there, doesn't he

 

I read it wrong the first time myself. I thought he said it would only start with the chain brake on. Then I saw what you said and went back and read the original post.

 

How old is this 026? Has it been sitting for an extended period of time?

 

Can you make the symptoms go away if you baby the throttle until the saw gets hot?

 

No it would sit but not neglected. Until now I’m waiting for better days to get back to this. If I could take a video of this maybe it could help ?

 

Somewhat but the problem was I think I let it idle too long. It smoked like crazy and then shutdown.

 

1st thing I would do is drain all the fuel and add fresh then change the spark plug and clean the air filter, probably not the issue but eliminate those as possibilities. Set the carb at the original settings which iirc are 1 1/4 on both needles. If you still have the same problem I guessing you need a carb rebuild or as some do just put on a new aftermarket carb. I have good results either way but I cycle carbs in a ultrasonic cleaner and I think that is required in some cases.

 

Sounds more like an airleak rather than a carb adjustment ,or clutch problem . Check your impulse line and carb boot for tears . Also check your fuel line for holes . If you can , pressure vac test it . The FW side seals can also be problematic on this saw . I wouldn’t run it until you elimiminate air leaks as a possible cause .

 

Sounds like an air leak. If this saw is equipped with a decomp valve it could be malfunctioning and causing an air leak.

 

Ok I’ll get this looked at soon. Thanks fellas. Good thing I have a back up.

 

I hope it’s an inexpensive and easy fix . Lets us know what the cause was . It’s always good to know what cures a particular problem for future reference .

 

A video probably would not help. I would start by looking at the fuel line closely.

 

I agree! It’s in the notes for the project. I want to have that chance where I actually sit or stand and work into this thing. The chance will come up very soon,