Stihl 036 pro problem

[enasnitsi]

I bought a 036 pro that wasn't running and I have been having problems getting to run right. It had low compression so I replaced the piston that was scored and the bad rings it had. I was able to clean up the cylinder. I replaced crank seals when I did all that since they were leaking when I checked them. I also rebuilt the carb. It will still not run correctly. I have spark. It will run for a couple minutes and than die and won't restart. I am pretty sure its a fuel problem but not sure what else to do. When it does run it won't rev up properly and just bogs and I've tried a lot of different settings with the low/hi screws. The fuel filter is new and the fuel line has no holes or cracks. The boot from carb to cylinder is in good shape no defects. What else can I check so I can get this running properly?

Thanks

 

[Sprintcar]

I bought a 036 pro that wasn't running and I have been having problems getting to run right. It had low compression so I replaced the piston that was scored and the bad rings it had. I was able to clean up the cylinder. I replaced crank seals when I did all that since they were leaking when I checked them. I also rebuilt the carb. It will still not run correctly. I have spark. It will run for a couple minutes and than die and won't restart. I am pretty sure its a fuel problem but not sure what else to do. When it does run it won't rev up properly and just bogs and I've tried a lot of different settings with the low/hi screws. The fuel filter is new and the fuel line has no holes or cracks. The boot from carb to cylinder is in good shape no defects. What else can I check so I can get this running properly?

Thanks

Impulse line?

 

[mbayer]

check the coil gap recently had a similar issue on a fresh rebiuld and that was the problem, had spark but not very strong and if it didnt take off right away it flooded out

 

[Griffbm3]

Impulse Tube

Hi There:

I too had a basket case 036PRO too. Fun saw, actually my favorite round the yard stuff...

If the fuel line, and fuel tank vent are fine as you say, then I would check the impulse tube on that saw. They tend to disintegrate on the 026's and I think the same can be said for the 036's, but mine was fine???

One turn out with a fresh plug and fuel should be fine for basic starting on the carb.

Since you said you did the seals, double check your coil gap, but you said it starts, I am just going through my checklist on computer...

Do you know for sure what seized it up the first time? I was working on a customers Husq 55 that would "bog" after WOT, and it turned out it was leaning out gradually due to build-up in the carb. It was leaning out so much that it was hitting the rev limiter, and at the same time eating the ring and piston.

I have had about 50-60% success rates with really small carbs for rebuilding cmopletely on horrible saws, but that particular carb should clean out okay.

Did you pull out both the H and L when you soaked the carb for the rebuild? How extensive was your rebuild? I have absolutely screwed up carbs trying to mess with welch plugs before I knew how to do them for real.

Let us know.

WELCOME TO AS
Jason

 

[enasnitsi]

I did replace that line so I would assume it would be ok?

 

[MN Ripper]

I had a fuel line on my 028 that looked good and was soft and flexible but it gave that saw fits every time you wanted to use it. I replaced it and it was night and day difference, I reset the carb needles and it was good to go again. I don't know if the line had a micro crack in it I couldn't see or if the ID was collapsed in the middle?

I'm redoing a 036 pro currently too and I just ordered new lines and carb kit along with some other things and I believe the line was around $10.

 

[Brian VT]

Pressure/vacuum test ?

 

[Sprintcar]

VAC and pressure test after seals?

 

[enasnitsi]

I never checked it again after I replaced the seals. I will do that tomorrow and see what I find out.

 

[Mastermind]

I never checked it again after I replaced the seals. I will do that tomorrow and see what I find out.

Good call. I've messed up a seal before and will again. Also, on the carbs an ultrasonic cleaner has been the single best tool I've bought yet.

Welcome to AS!!!

 

[enasnitsi]

If I removed the welch plugs in the carb could I have caused any problems? Is there a proper way to replace those that I may not have done?

 

[Griffbm3]

Well in an answer about Welch Plugs... I have messed up a few carbs thanks to those...

The reason they make Zama and Walbro tool kits is to prevent people from taking picks and small boring tools and prying off the plugs. It's amazing what happens when you pierce through them and don't stop in time. Slight damage to passages causes big problems...

I wasn't able to seat them well before I read up on it and got the tools.

After you do your pressure and vac test, which I almost bet will be fine, take a better look inside your cab again, and make sure one of them didn't pop off. They cement them in place at the factory, I will try to find reference to something on the internet, but I know it's out there.

Good Luck with that saw.

Jason

 

[enasnitsi]

I pulled the carb back apart when I did the pressure/ vac test. The carb looked good but cleaned it up again anyway. The pressure/vac tests were good. Will run good for a few minutes than will bog if held wot and than eventually dies and won't restart. Checked compression and its 120 but that was not hot. I know thats low but the piston and rings are new. What else am I missing?

 

[Mastermind]

I pulled the carb back apart when I did the pressure/ vac test. The carb looked good but cleaned it up again anyway. The pressure/vac tests were good. Will run good for a few minutes than will bog if held wot and than eventually dies and won't restart. Checked compression and its 120 but that was not hot. I know thats low but the piston and rings are new. What else am I missing?

If it's not the tank vent I'm not sure of a simple "try this next".

120 is way low on that saw as well.

 

[enasnitsi]

The tank does build up pressure because I can hear it when I open the cap but the saw doesn't run any better if I have the cap open so I don't think thats the problem. I know 120 is low but I have replaced the piston and rings already and the cylinder is in great shape it just hasn't ran at all except for like 30 seconds at a time.

 

[Sprintcar]

The tank does build up pressure because I can hear it when I open the cap but the saw doesn't run any better if I have the cap open so I don't think thats the problem. I know 120 is low but I have replaced the piston and rings already and the cylinder is in great shape it just hasn't ran at all except for like 30 seconds at a time.

Time for a new cylinder. If that saw is pulling 120psi cold, it won't break a hundred hot, if it ever got hot. Buy a new cylinder or an aftermarket kit from one of the sponsors.

 

[rupedoggy]

You honed it, didn't you? Mike

 

[enasnitsi]

Yes I did hone it and there isn't any scoring at all in the cylinder. I can run it for a couple minutes until it gets hot. I cut down a couple oak trees last night and it had plenty of power and never bogged at all but once it runs for a couple minutes and it gets hot it will start bogging and than die. It won't restart until it cools off and than will run perfect for another couple minutes. So its something that is starving it of fuel when it gets hot only just need to find out what.

 

[Mastermind]

Yes I did hone it and there isn't any scoring at all in the cylinder. I can run it for a couple minutes until it gets hot. I cut down a couple oak trees last night and it had plenty of power and never bogged at all but once it runs for a couple minutes and it gets hot it will start bogging and than die. It won't restart until it cools off and than will run perfect for another couple minutes. So its something that is starving it of fuel when it gets hot only just need to find out what.

Check your compression after it dies.

 

[enasnitsi]

Compression when it dies is 130. Which is lower than it should be but it should still run the same as when its cold.