Need Help Tuning MS290 Carb after rebuild!

[Ben Ruether]

Hey, I recently put a new jug and piston in my MS290 I also rebuilt the carb. I tried starting it today and it fired up first pull but than died when I gave it gas (this was in the run position). The spark arrester is clean and the saw has 40-1 mix. limiter caps are still on it. Any Help would be greatly appreciated!

 

[Deleted member 149229]

Screw your H & L screws in the whole way, do not over tighten. Then back each one out 1 full turn each for your starting point.

 

[Ben Ruether]

Screw your H & L screws in the whole way, do not over tighten. Then back each one out 1 full turn each for your starting point.

Okay thank you! I will Try this tomorrow and post a update!

 

[HarleyT]

You would need to remove the limiter caps first.

 

[Ben Ruether]

Okay I found the issue... At some point the impulse line came off the crankcase... Thats pretty embarrassing! I am thinking about buying a tachometer to do A more precise Tuning because I really don't trust myself too much. Any recommendations?

 

[smokey7]

Did you pressure vac test the saw after you rebuilt it? Or did you just rebuild the carb? I cant remember how hard it is to get the impulse libe back on without taking a bunch of stuff apart. Let us know how you make our

 

[Ben Ruether]

Did you pressure vac test the saw after you rebuilt it? Or did you just rebuild the carb? I cant remember how hard it is to get the impulse libe back on without taking a bunch of stuff apart. Let us know how you make our

This is a full rebuild and my first rebuild. I didn't do a vac test just because I don't have the tools... I ended up having to take off the carb and handle/top cover to get the line back on. The saw is running and sounds fine to me but I still want to get a tachometer. How important is it to do a vac test if the saw seems to be running fine?

 

[Brad2185]

Vac test crankcase to make sure crankshaft seals are not leaking. They can leak one way and seal the other.


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[Brad2185]

I just did 2 ms290 rebuilds and then a ms310 and just finished a ms390. Most of the parts will exchange

Getting those rear handle/top covers on are a pain!


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[Ben Ruether]

Vac test crankcase to make sure crankshaft seals are not leaking. They can leak one way and seal the other.


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Okay Will do! I will buy a vac tester and a tachometer and then get back to work on it. Your advice is greatly appreciated!

 

[Brad2185]

Wish we had caught ya in the middle of your build. With the engine apart its really nothing to through in 2 new crank seals. Cheap insurance...


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[Ben Ruether]

Wish we had caught ya in the middle of your build. With the engine apart its really nothing to through in 2 new crank seals. Cheap insurance...


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Honestly Im very surprised I got it Running at all. I inherited it seized from my father so I figured I would not be making it any worse by trying to fix it up!
Plus it was a great learning experience. What would you use to do a vac test?

 

[Deleted member 149229]

Mityvac makes compression/vac test kit.

 

[Ben Ruether]

Mityvac makes compression/vac test kit.

Okay This one says it "Bleeds brakes, tests vacuum switches and removes fluids"
should this work? Thanks!

https://www.kmstools.com/performance-tool-vacuum-pump-kit-147264

 

[Deleted member 149229]

Okay This one says it "Bleeds brakes, tests vacuum switches and removes fluids"
should this work? Thanks!

https://www.kmstools.com/performance-tool-vacuum-pump-kit-147264

From what the description says I would say no. I didn’t see any gauges and no fittings to hook into the spark plug hole to pressure test.

 

[Ben Ruether]

From what the description says I would say no. I didn’t see any gauges and no fittings to hook into the spark plug hole to pressure test.

Okay I saw another one made by Mityvac that would definitely work but it was on the pricey side... I think I will go ahead and get it And run a test and go from there. Thanks!

 

[Deleted member 149229]

Okay I saw another one made by Mityvac that would definitely work but it was on the pricey side... I think I will go ahead and get it And run a test and go from there. Thanks!

I happened to get mine at a good price on eBay.

 

[smokey7]

You can get the cheap vac tester and make your own pressure tester with a bloodpressure bulb. Or use your air compressor turned way down to 5-10 psi. Ive had carefully assembled saws leak around the pan especially with aftermarket parts. Good on you for taking our advise. It may be assembled right and sealed but this is how you know for sure.

 

[Ben Ruether]

Okay well I ended up ordering a MityVac pressure and vacuum pump with gauge and a more oil seals just in case there is a leak/damaged seals. I guess todays project is figuring out how to seal the intake and exhaust. I've seen it done with inner tubes but i don't have any around but I do have a old quad tire that i can cut up! I will take pictures as I go and upload them. Thanks everyone!

 

[Ben Ruether]

Got the intake side sealed nicely now time for the exhaust!


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