Build alert!! Another 038 Mag

[LondonNeil]

Really? Hmmm, when I tuned by super last week I had the idle far slower than your saw. Like you I had chain creep, although almost got rid of it but then the idle was so slow it sounded like a Harley, pop.....pop..... pop.....

 

[LondonNeil]

When you select some clutch springs let us know which please, I suspect I will be going the same route

 

[Adamski]

Really? Hmmm, when I tuned by super last week I had the idle far slower than your saw. Like you I had chain creep, although almost got rid of it but then the idle was so slow it sounded like a Harley, pop.....pop..... pop.....

I think there are some things to iron out with this still. You are right. It should go lower but it won't without stalling. I have tried richening the low up and speeding the idle to compensate. I have also leaned out the low and closed the idle to compensate. Neither give better results. New oem crank seals. Think the carb needs a going through..

 

[Wonkydonkey]

Umm, the Mrs would be saying WTF happend to the hand towl, like some hungry monster has had a chew on it....

But it's good that you brainstormed us to get a few answers, it got you thinking and got an answer. As for the tick over I think it sounds ok 2.5 k ish but you would only really know with a tach. Maybe a bit more of a finer tune of the carb ? You may get there, carbs can be finicky things at the best of times, and remember it's ported and gutted. And when warm it will behave differently IE slower
How does it sound at wot, does it 4 stroke ? Could be it needs less or more ! H and the corresponding tune on the L and then the LA.
I did say finicky
Anyway cut some wood and enjoy then look at the spark plug

Cheers

 

[Adamski]

Umm, the Mrs would be saying WTF happend to the hand towl, like some hungry monster has had a chew on it....

But it's good that you brainstormed us to get a few answers, it got you thinking and got an answer. As for the tick over I think it sounds ok 2.5 k ish but you would only really know with a tach. Maybe a bit more of a finer tune of the carb ? You may get there, carbs can be finicky things at the best of times, and remember it's ported and gutted. And when warm it will behave differently IE slower
How does it sound at wot, does it 4 stroke ? Could be it needs less or more ! H and the corresponding tune on the L and then the LA.
I did say finicky
Anyway cut some wood and enjoy then look at the spark plug

Cheers

Fortunately this said towel was a dog one, I did think about a tea towel but the saw sense in my madness.. Yep it is heavily 4 stroking on wot. Too much. You would have to be leaning on it a lot to get it to clean up in the cut. Like I said it is roughly tuned, better than last night by a long stretch. This now sounds more like the old 048 or 181se that I have had in the past. Lol. Maybe just needs a 28" bar or bigger to stop that slight chain creep.. hahaha.

 

[PogoInTheWoods]

Good to see (hear?) it making noise. Idle spec is 2300rpm, btw.

 

[Adamski]

Good to see (hear?) it making noise. Idle spec is 2300rpm, btw.

I will have a look on Monday evening again. Just to piss off our neighbours.. it is definitely more throaty than my first 038 mag I had.. I chipped some paint today when I was adjusting the chain tension, they say the first one is always the worse. I have come to terms with it this evening.

 

[LondonNeil]

Ouch.

 

[Adamski]

SKF bearings ordered. To be pushed into this case (case number 2), which will be going in for some glass blasting at my mates farm workshop.

I'll probably stay away from the bearing cups and mating faces with the glass, will fettle those bits after.

Also has anyone delved in the paint stripper approach with Magnesium cases, I know most paint stripper will corrode or 'white rot' magnesium?

I am hoping for an as new case after etch and top coat (RAL7035, thanks @LondonNeil)

 

[Glock37]

Split outer races of old bearings and push them into case to protect from blast 038 cases 2 races are needed after removing snap ring


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[Adamski]

Split outer races of old bearings and push them into case to protect from blast 038 cases 2 races are needed after removing snap ring


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Excellent idea, what about the mating faces and cylinder face? guess the gasket would take care of this?

 

[Glock37]

Bolt halves together to do outside cases blasting cyl area on case wont hurt just stay there long. Dont use gray tape to mask off when blasting leaves a gooy mess
Clean with hot soapy water then dry in oven then mask with heat tape and plug holes with sil plugs




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[Adamski]

Bolt halves together to do outside cases blasting cyl area on case wont hurt just stay there long. Dont use gray tape to mask off when blasting leaves a gooy mess
Clean with hot soapy water then dry in oven then mask with heat tape and plug holes with sil plugs




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My head is not screwed on this morning, didn't even think to bolt the case together to blast.. haha

Cheers

 

[Adamski]

This is what happens when the donor parts saws crank had a rod main bearing failure.. there are were no pins in the the crank, yet the cylinder is clean as a whistle.

 

[Adamski]

A few from this morning.. case heated on top of the gas hob. SKF bearings in a zip lock bag in the freezer overnight. Flywheel side dropped right in. Pto side needed a clamp, socket and a light tapping on the side of the socket with a hammer. Both in, easy peasy..

 

[Wonkydonkey]

I'm glad it slipped so easy.....said the nun to the bishop

shame about the brown stains thou

 

[Adamski]

So I’m not sure if I approached number 2 build as I should have. I was impatient and decided to install the crank before painting the case. I wanted to be able to wet flat the case and I had already pressed the bearings in. So I am now taking the approach of install the cylinder, blank off all ports and impulse etc and flat away with water (my personal preference)

Crank in the pto side bearing, hylomar blue and the gasket. Another coat of blue on the flywheel case and ta da..

 

[Adamski]

And the seals are in. Not sure if the pto one is ok. Will check when the cylinder is on. I have a feeling that I have bent the pressed seal slightly and the seal is slightly skew on the shaft.

 

[Adamski]

Did a bit of grinding on the cylinder the other week, nothing drastic... just cleaned off the lower transfer bevel for better flow, squared off the intake a little and widened the exhaust (width only) by approx 1.5mm either side. Finally managed to take some pictures of the exhaust. None of the ports have been re bevelled yet.

Picture of the widened exhaust port, nothing drastic. Not sure if I need more material removed (a bit more blending) from the port opening to the muffler? I’m not after a racer, just that little bit extra.

 

[Wonkydonkey]

I did a 44mm (260) the other day, I didn't take as much out, I just took the lip out/carried on with the same taper. I guess it it will flow better than it did but how much idk.