Ronie's 660 kit saw

[Maintenance Chief]

Looks pretty good for the money(I dont charge my time for hobbies) , there's a strange sound to that let off still? MAybe its the video but something doesn't sound like its returning to idle as it should.

 

[Ronie]

Yea, it doesn't return to idle as fast as I would like, not as bad as it was with the Hyway cylinder, but srcarr52 said it was the carb pop off and he wouldn't worry about it, so I'm going to let it be.

 

[Ronie]

@srcarr52 Could my timing advance be making the saw run on after the cut? The reason I ask is that it's done it with two different cylinders and two different carbs. It's advanced almost half a key right now. I'm thinking tomorrow I'll put it back stock and see how it acts but thought I'd see what you think before I did.

 

[huskihl]

Old fuel?

 

[Ronie]

Old fuel?

It's fresh

 

[Ronie]

The hotter it gets the more it does it

 

[Ronie]

Also the richer it is the more it does it

 

[srcarr52]

@srcarr52 Could my timing advance be making the saw run on after the cut? The reason I ask is that it's done it with two different cylinders and two different carbs. It's advanced almost half a key right now. I'm thinking tomorrow I'll put it back stock and see how it acts but thought I'd see what you think before I did.

Like I said before, I wouldn't worry about it. It's actually a rich on deceleration problem, due to heat soak, too little pop off pressure, too low vapor pressure fuel. It's not going to hurt anything, it's getting plenty of fuel in the cut.

On an 066/660 if it's not pulling the rope out of your hand when starting it's fine. They really like a lot of timing, they run even better when they bite you once in a while starting but no one likes tempting monkey fist over a few 10's.

 

[Ronie]

Like I said before, I wouldn't worry about it. It's actually a rich on deceleration problem, due to heat soak, too little pop off pressure, too low vapor pressure fuel. It's not going to hurt anything, it's getting plenty of fuel in the cut.

On an 066/660 if it's not pulling the rope out of your hand when starting it's fine. They really like a lot of timing, they run even better when they bite you once in a while starting but no one likes tempting monkey fist over a few 10's.

Ok, I'll just leave the timing where it's at. Thanks again for your help.

 

[drf256]

Thanks for the tips, I need all the help I can get. I was thinking of redoing that Hyway jug that I took off this saw and dropping the cylinder down so I can get the exhaust from 94 to 96/97 and see how it does there and putting the intake around 82.

You can try the old trick of notching the piston crown by the exhaust and seeing if it continues to gain. I missed whic brand slug you used, but the chiwanese ones are cheap enough to use for experimenting. When you start to lose, you just use a regular piston to go backwards.

 

[Ronie]

I'm going to put an OEM cylinder on today and see how it does. The plan was to put it on as is but I might widened the exhaust a little. I cleaned all the transfer off and it has a little scoring above the exhaust but I think it will be ok.

 

[Ronie]

Got it ready, widened the exhaust from around 30mm to 34mm and I'm going to use a good sized pop up that I cut for another cylinder and my squish will be .0175, I left everything else stock. Hopefully the scoring won't effect it, camera isn't picking it up but you can see and feel it in real life.

 

[MustangMike]

That cylinder will be just fine!

 

[Ronie]

I forgot to put the stock timing numbers up, it's the numbers on the bottom and were taken with a ring. The transfers openings are at an angle with the intake side opening first.

 

[MustangMike]

I'd bet on the Mahle!

 

[Ronie]

I'd bet on the Mahle!

It has a little deeper scoring and it needs the squish band cut.

 

[Ronie]

Made a quick cut with the OEM cylinder, it's faster, more torque and just feels so much better in the cut and it's not even tuned, just one turn out on the screws. Them other cylinders are turds compared to the OEM one that has almost nothing done to it.

 

[huskihl]

Made a quick cut with the OEM cylinder, it's faster, more torque and just feels so much better in the cut and it's not even tuned, just one turn out on the screws. Them other cylinders are turds compared to the OEM one that has almost nothing done to it.

Wonder how many oem cylinders have been thrown out because their new hot rod BB cylinder “runs so much better”.

 

[Ronie]

Wonder how many oem cylinders have been thrown out because their new hot rod BB cylinder “runs so much better”.

I've only tried a 372 BB and the one on the other clone 660, even with work they didn't even compare to an OEM one.

 

[huskihl]

I've only tried a 372 BB and the one on the other clone 660, even with work they didn't even compare to an OEM one.

They aren’t all that bad. I have a Tecomec cylinder on a 365 that runs as well as most. But it’s rare.
I ported a Meteor 661 cylinder and it was still 8% slower than stock oem. Pos