Stihl MS290 problems

[spudulike]

Hydrochloric acid (HCl in chemical terms) is available in small quantities from hardware stores, it is sold as "spirits of salts".

 

If you want more concentrate Hydrochloric acid, pop into your local car valeting suppliers, ask for steam cleaner de-scaler.

 

I bought a 5 gallon drum for £15, it is concentrated enough to smoke when you take the lid off the drum. Don't breathe the fumes or it will make your lungs hurt, don't get it in your eyes, or on your skin.

 

Another benefit, put half a pint down your toilet and leave over night, super strength Vical.(warn every one who may use the loo, that it has acid in it.)

 

It removes all the lime scale, she will be pleased.

 

H-A

 

Yes, she will if she drops a big one and gets acid up her crack:blushing:

[Aledafis]

I've re built the engine tonight, but it was a little late to start her up at 10.00 on a Friday night even for my neighbours. It was all quite straightforward in the end, all that googling and great advice on here must have been worth it!

 

So one last question (I hope) what's the preferred running in procedure? Do you just let them idle gently for a while before going for it, or is this not necessary?

 

Thanks for all your help guys!

 

Aled

[spudulike]

I've re built the engine tonight, but it was a little late to start her up at 10.00 on a Friday night even for my neighbours. It was all quite straightforward in the end, all that googling and great advice on here must have been worth it!

 

So one last question (I hope) what's the preferred running in procedure? Do you just let them idle gently for a while before going for it, or is this not necessary?

 

Thanks for all your help guys!

 

Aled

 

Set it a little rich on the top end - not really stupidly so but around 1K rpm off the top revs and then use it flat out - avoid doing loads of really big long cuts straight away one after the other where heat can build up but do use it flat out on some smaller ringing up and let it cool for a minute or two after a long cut.

 

The theory is that you want the bore and piston to bed in whilst there is no glaze on the bore and the rougher piston and cylinder surfaces can wear themselves in together before glaze stops this happening.

 

Try the H screw on 1 1/8 turn and set the L screw to one turn but be prepared to adjust for an even idle.

 

The idle will need adjusting as it all beds in but hopefully not too much.

 

Hope it all works out - the MS290/390 are right pigs to work on at the best of times - if you can strip one of these - other saws will be a lot easier:thumbup:

 

Good luck

[Aledafis]

Thank Spud, that's great, I'll give it a go this afternoon once I get back from the boys football match.

[Aledafis]

I'm back I'm afraid, the saw initially fired up as I'd hoped, but following a good few seconds of running it stoped, and after some frantic pulling I just couldn't get it to start up again. This happened this afternoon, so i tried it again after dinner and the same thing happened again. It's as if it'll start up from cold, but once it has warmed up a bit it just doesn't want to run at all.

 

Any advice would be gratefully received.

 

Aled

[Ray1]

What make piston did you put in? Are you certain you got all the transfer off the cylinder? Take the exhaust off again and have a look at the piston.

[Ray1]

Its more than likely a fuel problem, it sounds just like the impulse hose from the cylinder to the rear of the orange handle isn't connected.

[Aledafis]

The piston is fine and I have good compression, so as you say, it's probably a fuel issue. I fitted a carb kit yesterday, but I'll give it a good going over today again just to make sure that none of the nozzles are blocked.

[spudulike]

FYI - I have trouble with certain carbs, the ones on the MS390 and MS290 are one of them. The issues I had with a couple of them recently were that they would start the machine but then it would die.

 

I could get a few high speed revs and then nothing. I put these carbs in the ultrasonic cleaner, mine is a decent high power heated one, and bingo, they ran just fine. Not sure if it was build up af crud in the carb or what, my usual suspect is a blocked High speed check valve but it did the trick.

 

Carb cleaner may do it for you but this is what I have found with this saw model......and it drove me mad and cost me a lot of time as I pulled a faulty carb of one machine and put a carb of another machine on it and it still had the same fault - e few hours of checking later, I found both carbs were bad:001_rolleyes:

 

Other than that, fuel lines, fuel filters, tank breather, inlet manifold and impulse line may all be at fault.

 

Good luck....it will make a man of you:lol:

[Aledafis]

Hah! It's good to know that it's not just me then. We have an ultrasonic cleaner that the missus uses for her jewellery, I'm sure she won't mind me cleaning my carb in there...

 

I've not changed the fuel line as it looks OK, I'll have another look and maybe order a new one just in case, they're only a few quid. The tank breather has a screw in doo dah, could that be problematic?

 

It's not going to beat me!!