Ms660 big bore. Yeah I know.

[MG porting]

I realise that most of the big bores have the problems with freeporting and like all of them the finish work on the port's suck this one is a farmertec and I'm going to be working it over I've already filled the exhaust port with the extreme heat JB weld the exhaust port will be widened so I'm not worried about flow I'm working on the cylinder when I get spare time which is slim right now but I'll be posting my progress as I go.

 

[Deets066]

Just oiled the piston for a stop?

 

[Nutball]

I just ordered some JB EH a couple hours ago, good to see you about to try it. I was thinking wrap the piston in wax paper for a tight fit, then apply.

It doesn't say much about being an adhesive, no strength ratings, just a crack repair/gap filler.

Is there an easy way to mix up only as much as you need? I get the impression from the package design that you have to mix all 3oz at once.

 

[huskihl]

I get the impression from the package design that you have to mix all 3oz at once.

Well that would suck.
I just got some but didn't look at the details yet

 

[MG porting]

Just oiled the piston for a stop?

Grease but you still have to know when to get it out or it's a pane to get out.lol

 

[MG porting]

I just ordered some JB EH a couple hours ago, good to see you about to try it. I was thinking wrap the piston in wax paper for a tight fit, then apply.

It doesn't say much about being an adhesive, no strength ratings, just a crack repair/gap filler.

Is there an easy way to mix up only as much as you need? I get the impression from the package design that you have to mix all 3oz at once.

It has 300 pounds of holding strangth so they say but it's okay to mix it all and use what you need and put the cap back on I applied it in lairs it's not like other jb weld but if you're payshint it should be fine and yes let it dry don't rush it I did the first go round and ended up doing it over.lol

 

[Nutball]

I wonder how thick it can be applied at once?

 

[MG porting]

Well that would suck.
I just got some but didn't look at the details yet

You need to scuff up the service and clean it up really good prep is everything but I'll be the test dummy if it does what they claim they say it does then it should work.

 

[MG porting]

I wonder how thick it can be applied at once?

It's gritty and thin and I noticed that itsi easy for air pockets so it's all up to you on how brave you want to be.

 

[huskihl]

It's gritty and thin and I noticed that itsi easy for air pockets so it's all up to you on how brave you want to be.

Try some heat on it next time and see if it thins out and flows better. Might eliminate air pockets

 

[MG porting]

This is the second go around with this stuff I have enough built up I strongly suggest that you use a round file to shape it and sand paper to finish but thstha just me.lol .

 

[MG porting]

Ok it's rufed in it's easy to work with so like I said I recommend using a round file and sand paper.on the piston
I marked it with the piston all the way up against the squish band so now I've go some room for a base gasket delete I still need to widen the port but so far I'm liking what I see. Stay toond.

 

[MG porting]

Got some more done today exhaust Port is finished im not going to polish it like a mere like I would normally would it's good enough for the test I did some work on the lower transfer's and poot in some bridge port's I put them forward from where I would have liked them but the bridges are pretty thin so had no choice. yes the transfers are ugly right now but I'm not finished with them yet.lol

 

[MG porting]

Intake oooo Mr intake and of course where it needs work is where I would normally ad JB weld on the bottom but it's so out of whack I'm going to fix it and then see how much JB weld I need to add to it.

 

[MG porting]

I'm going to back paddle on the intake I went ahead and just cleaned up the edges of the port and when ahead and tore into one of the lucky Saw's I'll post up the squish and timing numbers here in a couple days but I did run it and its a pig on fuel at 12600 now I got a jet in it that I reamed out so I'm thinking of putting a smaller one in because the high setting is right at 3/4 out but one full turn out on the low setting which the saw is idling at 2800 it sounds like a thumper no free port after filling the exhaust port yes I had to run the bass gasket it was a little tight with out it but still cleared but to tight. I'll post up the picture of the saw in a few. So far I'd say with some work the big bore can be a good runner get rid of the free port and some work on the transfers it can be a good.

 

[MG porting]

Here's the test saw this one is the one I always like to use when I want to to test something and I just like the saw and yes it has oem bearings and seals its close to my favorite saw but not yet we'll see how it does in the wood against my 064 with a 36" bar and chain it should beat the 064 but she's not quite stalk ether .lol.

 

[Larry B]

I built a 660 kit with a hyway big bore kit about a year ago. Good power but it used fuel like crazy. It would go through a tank of gas in less than 30 mins of cutting. I went through almost 2 gals of gas falling and bucking a 30" ash tree. I recently swapped the BB for a MMWS cross cylinder with a pop up piston. When the weather permits will see how it compares to the BB.

 

[MG porting]

I built a 660 kit with a hyway big bore kit about a year ago. Good power but it used fuel like crazy. It would go through a tank of gas in less than 30 mins of cutting. I went through almost 2 gals of gas falling and bucking a 30" ash tree. I recently swapped the BB for a MMWS cross cylinder with a pop up piston. When the weather permits will see how it compares to the BB.

It should run very well he knows what he is doing. Did you do any port work to the big bore at all?

 

[Larry B]

No. All I did was slightly radius the edges and do a base gasket delete. 015 squish with 187 psi. Compression. If it wasn't for the thing drinking like a sailor on shore leave i probably would have left the BB on it. It has a dual port muffler and max flow kit and 020 off the flywheel key. One thing I noticed is the MMWS idles better and has just a slight crisper throttle response. I was too lazy to put the degree wheel on the BB and check numbers.

 

[MG porting]

No. All I did was slightly radius the edges and do a base gasket delete. 015 squish with 187 psi. Compression. If it wasn't for the thing drinking like a sailor on shore leave i probably would have left the BB on it. It has a dual port muffler and max flow kit and 020 off the flywheel key. One thing I noticed is the MMWS idles better and has just a slight crisper throttle response. I was too lazy to put the degree wheel on the BB and check numbers.

This is my first big bore on a 660 and I didn't even bother running it as it came the one I'm using is a farmertec with the port work that I did and fixing the free port problem mine has a very snappy throttle response but a pig on fuel that's what really surprised me but if it cuts better than the 54mm bore then I'll leave it as is I'll get the timing numbers in a few days I'm doing this between working on other saws lol