036 rebuild

[NHRA1877]

Hey guys, I am just finishing up my ms290 build and will be starting the saw finally tomorrow. I picked up a 036 Pro for 100$ I did a compression test on the saw and it was 80 psi, the piston is scored which I knew when I got the saw, and just from holding this saw over the 290 I love it. I found a few sites with descriptions of building these saws but none had pictures.

I planed on keeping this build as cheap as I can while hitting all the important parts, it will be getting a new impulse line, fuel line, manifold, and seals. I was hoping I would be able to get a meator piston and rings through baileys and saving the cyl but once I got the cover off it looks almost like this saw has had a replacement cyl on it? What do you guys think?

Also, if I'm replacing the gaskets and seals on the motor do I need to do a pressure/vac test?

 

[Wagnerwerks]

Why do you think it's not a factory cylinder? Look at the base under the oil and dust for a Stihl or Mahle and a number. I'm not a stihl guy, but the many I've parted out all had those two markings. Looks like that jug may clean up. The piston isn't too horrible.

Good luck!

 

[tallfarmboy]

That saw must have been ran RICH, RICH, RICH with all that carbon in the exhaust.

 

[sefh3]

That saw was ran really rich. It looks more like carbon score than lean score.

 

[NHRA1877]

Thanks guys, I noticed there was a lot if carbon in there and there was more on the muffler and the spark plug is black!!

What normally causes a saw to run that rich?

If that's the case should I not bother putting new seals in the bottom end? If the cylinder will clean up and I can get away with putting just the impulse line fuel line and intake boot on I might spring for an OEM piston or is it worth it to do the one from baileys?

Also is there a way to check the crank bearings?

 

[Wagnerwerks]

The last meteor piston kit I bought came from terry landrum, a sponsor of arborist site. He's a great guy and treats you well. I'd go that route for the piston. The seals and other rubber bits are always a good idea. Why take chances?

 

[50blues]

Before you take it apart any farther do a vac. or pressure check. Make sure now its ok before you rebuild. If its good don't worry about the crank seals. pull the flywheel and the clutch and try to wiggle the crank. If it has noticeable play in the bearings they will need to be replaced. If there is no play and the seals hold a vac./ pressure test, the bottom end should be good.

Order a meteor piston, they usually come with caber rings. They are at least as good as original. If the intake looks good, pull and stretch it, look for holes or cracks, if its good no reason to replace it.

The carb. running rich, which made the carbon build up is usually just a carb adjustment. Easy fix.

This saw will make you happy. This is twice the saw an 029 is.

 

[Mad Professor]

Try cleaning up cyl with conc. HCl / muritaic acid(18% HCl).

I saved a nasty looking cyl, ......piston was worse than yours.

Alternate the HCl, with baking soda, green scungy/w detergent, water. 320 wet/dry if needed.

Wear gloves and eye protection. Have excess bicarbonate on hand if you spill HCl on yourself or surroundings.

P.S. Carbon. All I run is Golden Spectro at 50:1, since corn fuel, only with 100 LL AV gas. Be careful as 100 LL has lead. Hi at 1-1/1/4 is good for me with Muffler mod at 1500' elevation in the 036 I have.

 

[NHRA1877]

Thanks guys, I ordered new fuel line and impulse line, if I can find seals for cheap ill throw them on even if the old ones are good just for safe measures.

As far as cleaning the cyl, from what I have read all I need to do is: dip a Q-tip in the acid (which I can get at lowes?) and rub it on only the parts of the cyl that have scores, let it sit till it turns green and then dunk it in water, and sand with 320 a little, then repeat until its perfectly smooth, then hit it with any kind of detergent and I'm good to go?

Ill order up a piston from baileys and a carb kit and the saw SHOULD be back to normal. Anything I'm missing?

 

[Mad Professor]

buy the gasket kit

cheaper than the seals individual

post the cyl cleanup process, somebody here could help.

 

[Mad Professor]

[quote="Mad Professor, post: 4574788, member: 16108"

]buy the gasket kit

cheaper than the seals individual

post the cyl cleanup process, somebody here could help.[/quote]

Keep the acid from any aluminum, have NaHCO3 on hand. That is port edges and anywhere there is not Al transfer to the Cyl

 

[NHRA1877]

What exactly is the NaHCO3? Also is there anyone on the site that does cyl clean ups? If its cost effective it may be better to have someone who knows what they are doing clean the cyl up for me if its available

 

[sefh3]

You might be surprised to what that cylinder looks like. You are not seized that bad. You might only have a ring stuck causing the compression to lower. I would pull the cylinder first and take a peek inside. You don't have your decompression valve pushed in when testing do you?

 

[Big_Wood]

i just rebuilt the top end of an 036 pro. piston was uglier then yours and i saved my cylinder. i used the hyway piston kit from watsonr a sponsor here. he even has the gasket sets with seals for a great price. i check alot of saws but if memory serves it had 167psi after breakin which i found odd because i here everyone saying it should only have around 155psi. the aftermarket base gasket was pretty thin though. i would not doubt for a second that your sears gauge is blowing low. my piston looked worse then yours but i guess you never know exactly what happened with yours. my 036 pro had 129psi before the top end refresh. heck mine could even be blowing high but i have tested it against other testers and they were only a few psi out. oh ya and do yourself a favour, install new seals. the 036 has the same wimpy flywheel side seal that the 026 has.

 

[komatsuvarna]

I guess I'll be the one to say that is doesn't look rich to me. Even a normal tuned stihl has some oil residue around the exhaust port inside the muffler. Look at the very first picture, they's no sign of oil anywhere around the port at all. Ive seen a lot of lean seized saws with that crap in the exhaust port.

 

[Big_Wood]

I guess I'll be the one to say that is doesn't look rich to me. Even a normal tuned stihl has some oil residue around the exhaust port inside the muffler. Look at the very first picture, they's no sign of oil anywhere around the port at all. Ive seen a lot of lean seized saws with that crap in the exhaust port.

i had to let someone else say it. didn't want to get the guys who think they know all riled up . it looks like just a high hour saw to me. all the carbon build up has a white burnt looking film on it which would have been from when it went lean. most likely another stihl falling victim the that wimpy flywheel side seal leaking. when you have an ear for your saws tune this kinda stuff doesn't happen. there are many guys who will just force their saw to keep going. i did that once to a 272 and i'll never do it again. as soon as i hear it leaning out it gets shut off til i can investigate. no more just trying to finish the day.

 

[griffonks]

I have that compression tester and I think it reads low as the Schrader valve is under the gauge.

 

[komatsuvarna]

I have that compression tester and I think it reads low as the Schrader valve is under the gauge.

That would make it read low, specially on a small engine. With the schrader at the gauge, the hose adds a lot of area to the combustion chamber.

 

[NHRA1877]

The gauge is reading 80 psi so I figure even if the gauge is off by 20 psi were still only at 100 psi. The saw will start it didn't want to idle but I really didn't let it run much, just wanted to see if it would start. I ordered the meteor piston from weedeaterman with the 10% discount and free shipping. I will call the local dealer tomorrow and see how much the gasket kit with seals will be, I am going to replace the seals anyway as the dealer wants 45$ to do a vac/pres test so I might as well just spend the money and do the seals either way.

Any info on guys from the site that will clean and prep a cyl?

 

[Mad Professor]

What exactly is the NaHCO3? Also is there anyone on the site that does cyl clean ups? If its cost effective it may be better to have someone who knows what they are doing clean the cyl up for me if its available

Sodium Bicarbonate a.k.a. baking soda.

If you keep the acid off the aluminum (and yourself), and stay away from too coarse of abrasives, not too steep of a learning curve.

If the Nikasil is still there it is hard to hurt. If there are gouges/pits the acid will get under the nikasil and make things worse.

Hit everything with a scotchbrite and detergent first. Any oily residue will repell the acid. Do this after each acid and mild hand/fingertip wetsand, as carbon will act just like an oil.

Remember , hydrochloric acid is a gas, dissolved in water. Use with plenty of ventilation.