Stihl MS290 Nightmare Rebuild Questions…

[Alaskan Stihl]

Hey! It just dawned on me! I looked at the old a Stihl Cylinder (the one that I removed) and it has the same issue as the Aftermarket does (the Ridge in the Seal Saddle is ground flush…missing).

Here are a couple pictures of what I am talking about…(Note: You might have to view the thumbnails to get a more clear image).
The first picture shows the “Outer Ridge in the Flywheel Side. As mentioned, it keeps the Seal in place and keeps it from popping outward. The other picture is if the Clutch Side and has no ridge. The Stihl Base Pan is manufactured the exact same way (ridge on flywheel side…no ridge on clutch side).

My guess is that…on my (2) Halves (Cylinder =Aftermarket and Base=Stihl)…are not a perfect round fit. Or moreover, the two holes for the Seals don’t match up perfectly….either case causes the Seal to Pop out when I tighten it up to cinched.

I guess I will find out just how bad things are after everything cures tomorrow and I run the PSI/VAC Test…fingers crossed. XX

As mentioned, that Bar Oil Pump has a “Inner Ridge” that acts as a barrier to keep the Seal from popping out when the Base Bolts are tightened….not to mention that it is bolted in place to keep the seal in check as well.

 

[Alaskan Stihl]

Jasonrkba: AHA! That tool makes sense! I see how that hook end allows the end use to pop out the limiter stop…
Problem is….price of course (shwang) there goes another $25 bucks!

I will have to order one off of eBay, since I would only catch grief from trying to purchase such a secret and controversial tool from our local Stihl Parts Store! HaHa!

 

[Alaskan Stihl]

Finally got the saw to test! All assembled and waiting fir a replacement carburetor to arrive!!!

fingers crossed. XX

 

[Alaskan Stihl]

Replacement Carb arrived. Installed. Pulled Rip cord 4 times...She started right up! Had to adjust the carb a bit (L screw), now it idles perfectly....runs perfectly! Done Deal! SUCCESS! Thanks all!

 

[Wow]

Replacement Carb arrived. Installed. Pulled Rip cord 4 times...She started right up! Had to adjust the carb a bit (L screw), now it idles perfectly....runs perfectly! Done Deal! SUCCESS! Thanks all!

Very interesting reading..Years ago I made a Holly carb fit a ford Pinto..I made an adapter plate entirely by hand..To install the Carb I used carriage bolts and lock nuts..Once I set the carriage bolts into my aluminum plate the shoulder on the bolts acted like Studs..My working on stuff like that days are behind me.. I hope.. BUT,, now looking back,, Do you wish you had used a 391 kit. I've considered making my sthil O29 into a bigger saw BUT it 's heavy enough already.. Ha. Ha..Cuts well for a 54cc saw. I don't think it's a super.. which I believe is a bigger motor.. Heck at 75, I can't remember.. My best friend is 72. We visit and chat and then we forget stuff together. Ha. Ha.. Enjoy your youth. It fades and one day, you wake up with a back ache. it comes and goes for a few years and then you look into the mirror and realize you got old..I tried closing one eye so see if I would look ONLY half as old.. NOPE,, it don't work..Still look old.. Smile. Be blessed..

 

[cookies]

Very interesting reading..Years ago I made a Holly carb fit a ford Pinto..I made an adapter plate entirely by hand..To install the Carb I used carriage bolts and lock nuts..Once I set the carriage bolts into my aluminum plate the shoulder on the bolts acted like Studs..My working on stuff like that days are behind me.. I hope.. BUT,, now looking back,, Do you wish you had used a 391 kit. I've considered making my sthil O29 into a bigger saw BUT it 's heavy enough already.. Ha. Ha..Cuts well for a 54cc saw. I don't think it's a super.. which I believe is a bigger motor.. Heck at 75, I can't remember.. My best friend is 72. We visit and chat and then we forget stuff together. Ha. Ha.. Enjoy your youth. It fades and one day, you wake up with a back ache. it comes and goes for a few years and then you look into the mirror and realize you got old..I tried closing one eye so see if I would look ONLY half as old.. NOPE,, it don't work..Still look old.. Smile. Be blessed..

The 290's I re built into 390's might weigh 100 grams more or about 1/4 of a pound. Imo it has the opposite effect meaning its easier on the user and the reason is it simply has far more torque taking 1/3 or even 1/2 the time for larger cuts.

 

[a. palmer jr.]

Sometimes I have a little trouble getting the engine in the plastic case, thanks mostly to the bar mount extension on the bottom cap. There's a way of twisting it into the case but I usually forget how I did it last time... I have a 390 apart right now and the next step is installing the engine after I clean the case up a bit..

 

[Alaskan Stihl]

Yup, now, I wish I would have put the larger Piston & Cylinder in (this was my first rebuild and I didn’t want any surprises along the way, so I went with stock).

I read where some modification to the plastic cowling (or something) is required to make the larger engine fit? That was one of the contributing factors on going with stock block (albeit it was aftermarket).

Been using the saw a couple months now and the dang thing purrs like a kitten. Starts right up….idles like it should….revs like it should…cuts like it should….HOWEVER….it just lacks those few extra CC’s required to cut smoothly through larger diameter trees.

Nothing to panic about though, I just cycle to trigger a couple times to adjust the cut and continue….but if I had it to do over….

 

[a. palmer jr.]

Yup, now, I wish I would have put the larger Piston & Cylinder in (this was my first rebuild and I didn’t want any surprises along the way, so I went with stock).

I read where some modification to the plastic cowling (or something) is required to make the larger engine fit? That was one of the contributing factors on going with stock block (albeit it was aftermarket).

Been using the saw a couple months now and the dang thing purrs like a kitten. Starts right up….idles like it should….revs like it should…cuts like it should….HOWEVER….it just lacks those few extra CC’s required to cut smoothly through larger diameter trees.

Nothing to panic about though, I just cycle to trigger a couple times to adjust the cut and continue….but if I had it to do over….

No difference in the size of the 390 vs the 290 engine, entirely a bolt on procedure, I don't hesitate in putting a 390 into any 290 I have. There are a few mods I do to make it even better, like a muffler mod (slightly) and sometimes I install a carb such as from an 046. The only difference in plastic would be if your 390 came with a compression release then you'd need a hole in the top to be able to push it in, or just plug it off..

 

[Captain Bruce]

Very interesting reading..Years ago I made a Holly carb fit a ford Pinto..I made an adapter plate entirely by hand..To install the Carb I used carriage bolts and lock nuts..Once I set the carriage bolts into my aluminum plate the shoulder on the bolts acted like Studs..My working on stuff like that days are behind me.. I hope.. BUT,, now looking back,, Do you wish you had used a 391 kit. I've considered making my sthil O29 into a bigger saw BUT it 's heavy enough already.. Ha. Ha..Cuts well for a 54cc saw. I don't think it's a super.. which I believe is a bigger motor.. Heck at 75, I can't remember.. My best friend is 72. We visit and chat and then we forget stuff together. Ha. Ha.. Enjoy your youth. It fades and one day, you wake up with a back ache. it comes and goes for a few years and then you look into the mirror and realize you got old..I tried closing one eye so see if I would look ONLY half as old.. NOPE,, it don't work..Still look old.. Smile. Be blessed..

We are all either on that path, OR, are walking in circles looking at each other. Never stop tinkering!!!!