Cracked transfer, What can i do?

[Tim]

Today I milled a small Ash bout 11" diameter and got nine 3/4" boards. The saw ran great and seems to have lots of power. It didn't stall once but after shutting it down for a while it would not start so I sanded the electrodes on the spark plug and re gapped it and it started right up. It did that twice while I was working and again after I picked up and got back to the house. I tried to start it and had to put a different plug in to get it to start. I'll have to get a new plug to see if that will help.

I had to tune the H 1 - 1/2 out to get it to four cycle nicely when pulled out of the cut.

When I was messing with the saw before, it had problems stalling and difficulty starting when hot. I put a different coil in and also a different Nova module and it seems to be the same. The other coil was not tested or confirmed good but it didn't change anything. I'm wondering if maybe it just needs a new spark plug wire or cut a small amount off each end and reinstall it. I'll try a new plug first. The cleaned up carburetor made a huge difference. I think it could benefit from an even better carb.

Overall it seemed to be fine except the hard starting. I'll report back when I use it with a new plug and I'll also look through the spark plug hole for signs of transfer.

 

[bikemike]

Hi folks
I have a really nice KS Stihl 064 cylinder here that has had the spark plug thread repaired.
The thread repair is good, but whoever did it left a chunk of something hard in the motor and when they fired it up it jammed between the piston and the transfer bridge.

It totaled the piston and cracked the transfer bridge.

View attachment 25658

I was planning on porting a cylinder but figure if this one can be saved and made to run well somehow, I will use it.

What would people recommend?

Shame its on the exhaust side

I have been told it can be ground out

Cut it out clean it up and maybe fingers too

 

[Tim]

A few days ago I did some more milling and the hard starting was still a problem even with a new spark plug. I ended up putting a good tested ignition in and ran it today and it ran great without any problems. I milled a small log and got eleven 3/4" x 6" x 6' boards.

I'm pretty sure the saw is fixed now. I'll know for sure when I run it more. It seems to be running great and has plenty of power.

 

[Tim]

I pulled the muffler and checked for transfer and there was more transfer again. There was a lot more on the exhaust side this time but I couldn't get a good picture. I'm hoping that it was just from the little that I ran it with the other ignition. I'll clean it up and see how it goes.

It seems to be running perfectly normal now so if it happens again then I won't know what to check. Before I pull the cylinder I'll pressure test it to see if there is a leak.

 

[BuckthornBonnie]

Are we thinking that the problems are related to your open transfers?
Milling is hard on saws... how does it sound at wot?

 

[Tim]

It sounds fine to me at full throttle. It four cycles nicely and I've been running it a little rich doing light milling. I did temporarily switch cylinders and the other came out clean with no transfer.

I suspect the Golf piston. It has low hours but was scored up a bit when I ran it with the cracked bridge. I've heard before that matching the piston letter with the cylinder was good but my cylinder is stamped with a C and the piston is stamped AB. Not sure if that could cause problems or not. I've also read mixed reviews on the Golf pistons. I just ordered a cheap $22 piston from CGI on eBay. I've never tried that one.

I'm also wondering if there might be a small crack somewhere that only leaks when hot. When I got the saw it had transfer in the cylinder and every time I've had to take it apart I've had to clean a little transfer. It's had different carburetors, different ignitions and different pistons and always gets little black lines I'm assuming is transfer. When I tried a different cylinder on the same case and then pulled it there was not a trace of transfer. I've worked on a bunch of these 056 and this one has by far given me the most trouble. If it keeps happening I may just run it until it's burned up. I have a few more cylinders that will fit but they are smaller. Maybe I'm just getting carried away about cleaning the black lines out. Maybe it's just wear on the plating that gets polished up and looks black. I have old cylinders that are all black polished looking except under the transfer ports where the piston doesn't touch.

 

[BuckthornBonnie]

K. If it were me I'd change that piston if it was already damaged before. I've never used a golf brand. Does Meteor make an 056?
Saws can only leak in so many places (thankfully). A hot-only leak is probably not your problem.
I'm interested in this result as I've scrapped 460 cylinders with cracked/broken transfers... wished I'd kept em.

 

[Tim]

I'll wait until I get the new piston and then clean up the cylinder and see how it goes.

I have never seen a Meteor piston for the 056. I've seen Golf, CGI (Corea Group Inc.), Little Red Barn, and a few places sell generic no name ones. I bought a few generic pistons from Sagenspezi and the specifications were about the same as OEM but the compression started out a little low at 130 psi if I used the rings that came with them. I don't think the quality of the material is as good on the generics as OEM. Both Golf pistons that I bought had tight ring end gaps on the rings. One of the sets wouldn't even fit in the cylinder to test the gap, the other set was around .004".

I don't know what it's called but some of the pistons have holes where the transfer ports are and some are solid (see picture). I wonder if one style would be better with an open port than the other.

 

[BuckthornBonnie]

Windows?
Caber rings, if available, may help.

 

[Tim]

Yes, I guess they would be called windows. I wonder if one type (window or non window) would work better with an open port. They made both for this model but I don't know what difference it makes.

 

[Tim]

Well, the Corea Group Inc. piston turned out to be a Golf piston. I guess I'll be using another Golf. The ring end gap on one ring is so tight I couldn't fit a .002" feeler gauge between them. The other ring will fit a .005" feeler gauge.

Do people knowingly use rings that tight or is that just poor quality control? I thought they were supposed to be .010" or maybe .008" for this size. I have yet to get a golf piston with a set of rings with a normal end gap.

 

[Tim]

Without going back through this thread, have you vac tested this saw? If there's scoring every time you pull it apart, something is wrong, and I don't think it's your modified cylinder.

I think you were right about the vac test. When I was testing the vacuum pressure it would bleed down a little and I'd pump it back and then it would stay. I guess maybe the seals were moving from the pressure and sealing up. I put in new oil seals and it didn't do that this time. I ran the saw a little and so far no signs of transfer. It seems to run great now.

 

[Tim]

I now have put a new piston, rings and oil seals in the saw and did some light milling today with it. I started with some 8" wide cuts about 8' long for 2 x 8's and then made a couple wider cuts. It's all pine. The saw ran great and there are no signs of transfer in the cylinder. I think it was actually putting the new oil seals in that made the difference with the transfer.

I'll still be easy on it for a bit but so far it appears that none of the problems were from the bridges being removed. Judging by how it starts, cuts and idles I'd say it's fixed.

 

[blsnelling]

Well, the Corea Group Inc. piston turned out to be a Golf piston. I guess I'll be using another Golf. The ring end gap on one ring is so tight I couldn't fit a .002" feeler gauge between them. The other ring will fit a .005" feeler gauge.

Do people knowingly use rings that tight or is that just poor quality control? I thought they were supposed to be .010" or maybe .008" for this size. I have yet to get a golf piston with a set of rings with a normal end gap.

Golf should only be used as a last resort. I would definitely replace the rings with OEM or Caber, non-FCast.

 

[Tim]

Golf should only be used as a last resort. I would definitely replace the rings with OEM or Caber, non-FCast.

I already put the piston in with the rings that came with them. I did sand the ends of the rings so the gap was around .010". What is FCast and how can I tell if a ring is FCast or not? I do have a set of used OEM rings but they had a little scoring but will give good compression. I also have some new rings from a piston I got from Sagenspezi a while back. They are coated in black and I don't know the quality of those either. With all the work I've done on this I guess I could take it apart hopefully one last time to put in better rings. Are the FCast more likely to break?

 

[Tim]

I milled a small Hemlock log today and got five 1 - 1/4" x 12" x 11' boards. The saw seems to be running perfect and still no signs of transfer. I can't put better quality rings in yet. I do have some used but I'll wait until I can get some new Caber rings.

At this point I think if anyone has a cylinder with a cracked bridge but is otherwise in good shape then it is worth a try to remove the bridges. Only time will tell though. This is a milling saw, not a professionally used saw. I don't mill all day five days a week but I do use it quite often, usually anywhere from 2 to 6 hours per milling session. I have maybe around 2000 board feet worth of building materials to mill this year for projects so I can update if it breaks or if it holds up fine. I'm very happy with how it runs right now.

 

[BuckthornBonnie]

I milled a small Hemlock log today and got five 1 - 1/4" x 12" x 11' boards. The saw seems to be running perfect and still no signs of transfer. I can't put better quality rings in yet. I do have some used but I'll wait until I can get some new Caber rings.

At this point I think if anyone has a cylinder with a cracked bridge but is otherwise in good shape then it is worth a try to remove the bridges. Only time will tell though. This is a milling saw, not a professionally used saw. I don't mill all day five days a week but I do use it quite often, usually anywhere from 2 to 6 hours per milling session. I have maybe around 2000 board feet worth of building materials to mill this year for projects so I can update if it breaks or if it holds up fine. I'm very happy with how it runs right now.

I was hoping it'd work out for ya. Now I'm kicking myself for scrapping a 460 cylinder with a busted transfer. Oh well.

 

[Brewz]

Wow

I forgot about this thread.

I was talking to the fella that bought the 064 I fixed the cracked bridge on.
He uses it every day, all day to rip fence posts and its still going strong.
Used Chinese bearings in it too.

Looks like the repair worked

 

[smokey7]

What brank china bearings. Many big name bearings are china made now. But with qc they should be fine. Used many china parts on cars to find ones that worked well in each application. Lmk im currious