Neotec 660 clone

[Maintenance Chief]

Carburetor

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Don't be surprised if it doesn't idle all the way down, thr fix is an oem walbro throttle plate.

 

[Ronie]

Don't be surprised if it doesn't idle all the way down, thr fix is an oem walbro throttle plate.

Do you know what's keeping the Chinese one from working like it should, maybe not closing all the way? I'll look at mine and see if it does.

 

[Maintenance Chief]

Do you know what's keeping the Chinese one from working like it should, maybe not closing all the way? I'll look at mine and see if it does.

With mine it was just the hole in the center of the throttle plate not allowing the plate to sit flush in the bore. I could have egged out the hole but I had a heavily damaged carb for parts. Basically if you adjust the idle screw out and hold the choke open , then hold the carburetor up to a light you should see VERY little light or none ideally.
Personally I think they mirror imaged the knock offs which threw off the geometry of the plate.

 

[Ronie]

I backed the idle screw out and it closes pretty tight, the only other thing I can figure is that the hole in the plate is to big.

 

[Maintenance Chief]

That looks pretty good

 

[Lightning Performance]

You might end up with a good milling saw. The lower rpm feeds the motor more imo. Your numbers would be close for a dedicated milling saw.

 

[srcarr52]

Numbers for the cylinder that came with the saw, by eye.

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That is a lot of blowdown but at lease the intake isn't out of the park already. Cut the squish a little, don't touch either ex top or intake bottom and grind the transfers a lot and you'll have a runner.

 

[Billy Currie]

Your stock cylinder does not look like farmertec to me, it appears to be chrome plated with a machined squish band and a different symbol in the center of the combustion chamber.

Doesn't look like mine either. Ronie's cylinder look's much better than mine, and he isn't using his.

 

[Billy Currie]

I'd like to see the replacement cylinder...…..would Neotec be better than Hyway?

 

[Nutball]

At least you can easily port that cylinder, I'd be reluctant to work on a Hyway due to plating chipping issues.

 

[Redfin]

That is a lot of blowdown but at lease the intake isn't out of the park already. Cut the squish a little, don't touch either ex top or intake bottom and grind the transfers a lot and you'll have a runner.

I like this idea Ronnie, you can cut squish and run with no gasket? You have a ra for trans?

 

[Ronie]

I like this idea Ronnie, you can cut squish and run with no gasket? You have a ra for trans?

I'll clean up the ports on the original cylinder and see how the saw runs with it. I have a dental ra and will try to decrease the blow down and I'll make a thinner gasket to bring the squish down.

 

[Ronie]

At least you can easily port that cylinder, I'd be reluctant to work on a Hyway due to plating chipping issues.

I don't know how this new type of plating would chip like their old plating does. If the original runs good, I'll leave it on the saw and sell the Hyway I ordered or keep it for a spare.

 

[Ronie]

I'd like to see the replacement cylinder...…..would Neotec be better than Hyway?

I'll get some timing numbers off it before I put the original cylinder back on. It left California yesterday so I won't be able to get them for a few days.

 

[srcarr52]

I'll clean up the ports on the original cylinder and see how the saw runs with it. I have a dental ra and will try to decrease the blow down and I'll make a thinner gasket to bring the squish down.

They do pretty well at around 23deg blow down, so you only have to raise the transfers around 0.020". Hopefully you can get the port stager in there, open the ex side first by 0.015" ~1.5deg opening.

 

[Ronie]

I just finished cleaning up the cylinder, just need to take some sand paper to the bevels, and the port timing by eye is,

EX 96
TR 120
IN 80

 

[Ronie]

They do pretty well at around 23deg blow down, so you only have to raise the transfers around 0.020". Hopefully you can get the port stager in there, open the ex side first by 0.015" ~1.5deg opening.

Do you mean that I should split the each transfer in half and raise the exhaust side?

 

[srcarr52]

Do you mean that I should split the each transfer in half and raise the exhaust side?

Grind the transfer roof so the exhaust side opens 1.5deg before the intake side. The roof is still one section, but angled in the bore.

 

[MustangMike]

I thought TM always liked to make them level???

I think his 066s dynoed higher than any I have seen.

 

[Ronie]

Grind the transfer roof so the exhaust side opens 1.5deg before the intake side. The roof is still one section, but angled in the bore.

I see what you mean, thanks.