Slant 660 - Late to the party

[bottlefed]

Hello XD,
The reason I came back here, is I just got done working on the saw and I wanted to tell you I screwed up on the gas cap seal...even though the cap looks the same in the Stihl diagram, the seal is smaller in circumference...if you already ordered, my apologies and I will be happy to buy you a beer the next time I am in Washington state

Since you asked, yeah I did the OEM pin as well for two reasons one I had already run a couple of tanks of gas through it with the FT bearing, so it already had a wear pattern. To me it just seemed good insurance since the pin serves as the inner race of the bearing and is made of pretty soft steel compared to OEM (not much you can do about the rod LOL)..also a stiffer pin (in principle) will help insure the piston lives longer and the rings seal better.

Anyhow gotta find someone with a 24" or larger oak or other hardwood so I can turn the trunk into wood pizza's and see how the Asian Girl holds up in the cut.

PS On the tear down today after already running a tank or two of gas through it (hard to tell with the gas cap issues LOL) the piston/jug/crank/etc. all looked good. I ran the saw on Stihl ultra at 32 to 1 and put it through a couple of cuts to warm it and reseat the rings and then tuned it to 12,000 and it seems really happy. Pops on first pull and starts runs on the second. Its got about 175 psi cold, can't wait to get it in some fresh wood and see how it cuts with the 28" bar & full comp chisel setup.

 

[XD40SW]

Hello XD,
The reason I came back here, is I just got done working on the saw and I wanted to tell you I screwed up on the gas cap seal...even though the cap looks the same in the Stihl diagram, the seal is smaller in circumference...if you already ordered, my apologies and I will be happy to buy you a beer the next time I am in Washington state

Since you asked, yeah I did the OEM pin as well for two reasons one I had already run a couple of tanks of gas through it with the FT bearing, so it already had a wear pattern. To me it just seemed good insurance since the pin serves as the inner race of the bearing and is made of pretty soft steel compared to OEM (not much you can do about the rod LOL)..also a stiffer pin (in principle) will help insure the piston lives longer and the rings seal better.

Anyhow gotta find someone with a 24" or larger oak or other hardwood so I can turn the trunk into wood pizza's and see how the Asian Girl holds up in the cut.

PS On the tear down today after already running a tank or two of gas through it (hard to tell with the gas cap issues LOL) the piston/jug/crank/etc. all looked good. I ran the saw on Stihl ultra at 32 to 1 and put it through a couple of cuts to warm it and reseat the rings and then tuned it to 12,000 and it seems really happy. Pops on first pull and starts runs on the second. Its got about 175 psi cold, can't wait to get it in some fresh wood and see how it cuts with the 28" bar & full comp chisel setup.

Thanks for the info.

I didn’t order seals yet. Just a bearing. We have a pretty vast assortment of o-rings at work... I was gonna try to scrounge something up there.

Hopefully my bearing will be in next week some time. I’m currently at a standstill on the build. I’ve got the bottom end completely assembled, but I’m waiting on the bearing to slap the top on.

Unfortunately it may be a while before I get a chance to truly test it out. Due to extreme fire conditions, our governor has issued a temporary ban on chainsaw use and recreational target shooting. Both of the things I do for fun


Sent from my iPhone using Tapatalk

 

[XD40SW]

Just got my wrist pin bearing in today.

I measured squish with a base gasket at .041, and without was .020.

From what I’ve read it seems .015-.020 is ideal, so I’m thinking I’ll do a base delete. Am I correct here?


Sent from my iPhone using Tapatalk

 

[brshephard]

Just got my wrist pin bearing in today.

I measured squish with a base gasket at .041, and without was .020.

From what I’ve read it seems .015-.020 is ideal, so I’m thinking I’ll do a base delete. Am I correct here?


Sent from my iPhone using Tapatalk

Yep, go for it.
Don't forget to use some sealant in lieu of a gasket to prevent air leaks.

 

[XD40SW]

Um...

I must not have fully torqued the cylinder bolts last night. I just wanted to check some squish measurements, and I didn’t want to risk stripping out the threads in the case. So, I was a little easy on them.

I assembled the cylinder today, minus the base gasket and she banged her head. I pulled it off, and put a .5mm gasket in. I torqued the cylinder bolts, now I’m getting a squish measurement of .031-.032” all the way around the piston.


Sent from my iPhone using Tapatalk

 

[brshephard]

Um...

I must not have fully torqued the cylinder bolts last night. I just wanted to check some squish measurements, and I didn’t want to risk stripping out the threads in the case. So, I was a little easy on them.

I assembled the cylinder today, minus the base gasket and she banged her head. I pulled it off, and put a .5mm gasket in. I torqued the cylinder bolts, now I’m getting a squish measurement of .031-.032” all the way around the piston.


Sent from my iPhone using Tapatalk

You can hand sand 12 thou pretty easily if you want. Or make a thinner gasket from cardstock.

These aftermarket cylinders can have big combustion chambers, so reducing squish might offer some gainz. Depending on where your compression ends up.

 

[smokey7]

One thing i recommend is to lay a long piece of solder in 2 places at one time. The pieces should be long enough to measure the whole squishband. So if the band is 1/2" wide then solder should be at least1/2" long. Ive seen some have the band machined tighter towards the center of chamber and wider/looser closer to cylinder wall (opposite of what it should be). Another very good reason to sand the band some to remove the weird high spots out.

 

[bottlefed]

I built my 660 back in mid july and mine also hit the head without the gasket.....seems Farmertec is addressing the common issues one by one and that the recent run of jugs/cases are running a lot better as far as this goes.

 

[MustangMike]

I did not run any of the FT jugs, got the Cross P+C for all of them.

 

[XD40SW]

I’ve got my saw built and a few tanks of fuel through it now. I’m noticing a slight vibration, and I believe it’s the flywheel. It seems like it’s not properly seating.

I used a torque wrench on it. It’s torqued to 33 ft/lbs. But when I hold the crank steady, I’m able to move the flywheel ever so slightly. It’s way less then one degree of movement, but I’m able to see and hear it.

I was contemplating putting a dab of red thread locker in it. I just don’t want it to bite me later. Has anyone else experienced this? If so, what was your solution?


Sent from my iPhone using Tapatalk

 

[smokey7]

Your flywheel moves on your crank? Or are you feeling the dwel of tdc and bdc?

 

[XD40SW]

Your flywheel moves on your crank? Or are you feeling the dwel of tdc and bdc?

It appears the flywheel moves slightly on the crank. When I hold the crank perfectly still, I’m able to SLIGHTLY move the flywheel. It’s less than one degree. It’s hard to see, but I’m able to feel and hear it as well.


Sent from my iPhone using Tapatalk

 

[Wonkydonkey]

Just a thought, if you hold the clutch (not the clutch drum) while you try and move the flywheel, that way you will know if it is the fly wheel or something more sinister, I think @MustangMike knows what I’m saying .

 

[MustangMike]

Sounds like a bad bearing to me, I very seriously doubt your saw would run if you could move the flywheel on the crank (the flywheel would spin).

 

[MustangMike]

My saw developed a vibration when the piston pin bearing went, but sounds like you have a bad main bearing.

Did you flush them before you assembled the saw? I have had a lot of crap come out of my bearings when I flush them.

 

[XD40SW]

I flushed the bearings really good I thought. I used an OEM wrist pin bearing as well.

I had a socket on the flywheel nut, I turned the ratchet until I was fighting the compression and kept tension on it. I grabbed the flywheel with my other hand and I was able to wiggle it just a little bit.

I’ll mess with it more tomorrow. I’ve got bigger fish to fry tonight.

Sent from my iPhone using Tapatalk

 

[MustangMike]

When you tighten the flywheel, pull the plug and insert a stop (or piece of rope). Make sure piston is above exhaust port when you insert rope/stop.

 

[Wonkydonkey]

So the fly wheel has a taper on it. Yes there is a key and a key way to line it up (we play here to file the key to advance the timing) , the only way the flywheel will move on the crank shaft, is if it’s not tight enough. I think(know) there are torque settings. But most peeps do what mike says withe the rope.

Btw, the last time I did not tighten up the 200t flywheel enough, after a few bips on the throttle it fluffed up the flywheel keyway..

 

[bottlefed]

Look at the gap between the flywheel and the coil and push and pull the end of the crank toward and away from the coil and see if the gap gets bigger/smaller as you do so....if it does then your bearing is likely toast.

As others have said the flywheel and crank are tapered...its the taper that provides the lockup between the flywheel and crank, the key is there mainly to provide a rotational index point for the flywheel. The only way I could envision what the flywheel being loose is if the nut is not tightening against the flywheel due to the threads not being fully cut in either the nut or crank.....but IMO this is pretty unlikely.