The 1127 cylinder thread

I know, no self respecting AS member would be caught dead with a 290. As Thall pointed out a few weeks back, there are ALOT of lurkers on here. I'm sure there are some of them wanting to upgrade their 029's or 290's to "big bore."

OK, actually I have several 1127 cylinders on the bench getting some threapudic acid treatment. There was a guy on here a while back complaining that his "390" jug was only 47mm, instead of 49mm. I have taken pics of 4 different cylinders, and the markings on them. Maybe the info here will keep somebody from getting ripped off.

Plus, I heard that all of the cool kids are starting Stihl cylinder threads.

First up, group photo. Left to right 029 Super (46mm), MS-290 (46mm), MS-310 (47mm), 039 (49mm)


Close up on 029 Super


Close up on MS-290


The MS-310. Note that it does say 039, and it does not say "47" on it anywhere. Most Mahle cylinders have the bore on them somewhere, but not the 310. The "49" on here is very misleading.


This is the 039. Note that it also says "49" on it. I do not have a 390 one here right now. Last I checked they were similar. Of course, the later ones are easy to spot with the compression release.


Also notice the sealant. The older saws used some kind of grey sealant. The newer ones use the red Dirko. I was worried when I took my first 029 apart. I though maybe someone else had been in there fooling around, but I have seen a bunch of the older ones with the grey.

thanks......have you heard anything more from that high comp 290 that you mentioned last week???

A few pics for the quality control crowd. First is the 029 Super intake. Notice the polished intake flange. If I ever build a 46mm 1127 saw to keep, it will have an 029 Super cylinder on it. Comparing the 029 Super cylinder to the 290 cylinder is like comparing a Timex to a Rolex.


290 intake. Blah.


Exhaust flanges. The machining on the Super is sharp enough to cut yourself on. Not sure if the 290 is machined at all. Notice how nice the casting marks are on the older cylinder......


Two more, and I'm done. Here are the cooling fins on the head. Super is here. Probably harder to make the fins this way, but it sure looks like more fin area to me.


290 fins

These jugs

So are all these jugs interchangable then? or do some of these in between have different cranks or what not, I ask this just for future reference of repairing my stihl saws since it would give me a wider choice of replacement parts, just slap another jug and piston in if I find one from a friend ya know, thanks

B200, the old Dirko was grey, but all the new dirko tubes we get are now red. There was still some grey dirko left at the store when I started, but it had been there a while...

Same here, that grey Dirko was the good stuff too. The red stuff is too mealy.

Jacob J. said:

Same here, that grey Dirko was the good stuff too. The red stuff is too mealy.

Click to expand...

I agree 100%. I dont know that there is a heck of a lot of difference between the red dirko and regular rtv sealer, but I could be wrong.

Yamabond seems the same as the grey dirko that I've used.

The sealer we get from John Deere is the grey stuff, and I cant tell the difference between that and the old grey dirko.

It is made for sealing all the newer JD diesel engines, they dont use gaskets anymore...:bang:

But it is good stuff, I have used it on a lot of 2 cycle applications.

I have read the 029's not to popular on here, but I have had and used them. I don't have any at the time being but that will change. My last super was a good runner and a friend needed a saw so I sold it to him.

For what it's worth my experience on gray vs. red Dirko is that the gray applies more smoothly but the red will last many more years on 029 thru MS390 series saws. That's even been more evident on 021 thru MS250 saws and even FS80-style (4137 series) line trimmer, edger and pole saw engines. Just based on what I see at work.

bump

Just a note for some that may not know that the 029(45mm 54cc's) and 029 Super(46mm 56.4cc's) are two different saws. The 029 Super is the one that is exactly like the MS290 on specs.

I also had the gray sealant on my Super and used Red when I put it back together.

Seeing the jug pics, I guess I'm happy knowing I have the 029S. Quality did seem to go slightly backwards there, between the two.

If you need pics of the 390 jug and no one comes up with any by then, I may be taking mine apart in the near future to check cylinder wall(I see a couple score lines on piston). Mine has the decomp.

EDIT: WOW this thread is old. I thought I was reading something that started today. Didn't even look at the dates and just kept reading until I posted and saw the dates going back a few years.

Updated pics per Neal's request. I'll have to add a 45mm 029 and decompression 390 when I get in the shop again. I have both for show & tell.

Tnx