Hello! new guy here

[Larry B]

Hello my name is Larry and I am an addict. Addicted to things with small gas engines on them. I run a small mower shop and found the Stihl clone kits while looking for a AM top end for a customers 660. I really don't need a 660 type saw but hey, I just couldn't pass it up. So I got a clone kit and also a Hyway 56mm BB kit. I put the Farmertec 54MM on the customer saw and works fine but with the BB kit on the clone the compression is so high you can't pull it through at all unless the compression release is pushed in and then it is still harder to pull than a stock 660 without using the compression release. Squish with supplied Hyway gasket at .020. Just to try something I used 2 base gaskets and squish is about .038 and it is still stupid hard to pull. When it does fire using the CR it kicks back and rips the handle out of your fingers. Trust me on that. Timing is stock and using Stihl MotoMix. I cleaned up the ports on the cylinder but didn't change any timing. Hoping some of the experts here can enlighten me to what I am doing wrong. Waiting on the brown truck to bring my new compression tester. My old one from the 70's finally died. When I get it I can post what the compression is. Thanks for any help you guys can give.

 

[cus_deluxe]

Welcome to ope larry, maybe @Jon1212 can move this out of the subforums so it can get some more traffic?

 

[MustangMike]

Mine was near impossible to pull till it broke in a bit. My guess is the bearings are binding a bit. Hopefully, running it a bit will break it in like mine did. If not, you may need to disassemble a bit and tap the crank back & forth a bit.

 

[Jon1212]

Welcome to ope larry, maybe @Jon1212 can move this out of the subforums so it can get some more traffic?

Good call, Custer.

 

[cus_deluxe]

Liberal use of assembly lube will do what ur talkin about, u may have to run it hard a few times to really clean it out.

 

[Larry B]

Thanks for the replies. It's not a tight crank. Remove the spark plug and it pulls over very easy, spark plug in and not using the CR it feels almost like you hit a piston stop when you pull it over but if you hold pressure for a few seconds it will finally bleed off enough to get past TDC. There isn't any starting this thing. Even with the CR pushed in it has so much compression you can't pull it fast enough to start.

 

[Czed]

Hello my name is Larry and I am an addict. Addicted to things with small gas engines on them. I run a small mower shop and found the Stihl clone kits while looking for a AM top end for a customers 660. I really don't need a 660 type saw but hey, I just couldn't pass it up. So I got a clone kit and also a Hyway 56mm BB kit. I put the Farmertec 54MM on the customer saw and works fine but with the BB kit on the clone the compression is so high you can't pull it through at all unless the compression release is pushed in and then it is still harder to pull than a stock 660 without using the compression release. Squish with supplied Hyway gasket at .020. Just to try something I used 2 base gaskets and squish is about .038 and it is still stupid hard to pull. When it does fire using the CR it kicks back and rips the handle out of your fingers. Trust me on that. Timing is stock and using Stihl MotoMix. I cleaned up the ports on the cylinder but didn't change any timing. Hoping some of the experts here can enlighten me to what I am doing wrong. Waiting on the brown truck to bring my new compression tester. My old one from the 70's finally died. When I get it I can post what the compression is. Thanks for any help you guys can give.

Welcome to ope
Even this little china 372 was a handful starting i ditched the china decomp.
Didn't trust it.
After it broke in i don't need the
d ring but it's so handy and doesn't get in the way.
Do you have any run time on you' re 660?
For break in.

 

[drf256]

Welcome fellow addict.

It's been 3 days since I last touched a piston.

You'll love it here.

 

[paragonbuilder]

Liberal use of assembly lube will do what ur talkin about, u may have to run it hard a few times to really clean it out.

This^^^^^^
Been there done that...

 

[Duane(Pa)]

Nice & tight...Welcome Larry!

I'll ask Denise if she'll get your saw running for ya'. lol (just being silly)

 

[psuiewalsh]

Welcome fellow addict.

It's been 3 days since I last touched a piston.

You'll love it here.

Yours or a patient's?

 

[MustangMike]

Thanks for the replies. It's not a tight crank. Remove the spark plug and it pulls over very easy, spark plug in and not using the CR it feels almost like you hit a piston stop when you pull it over but if you hold pressure for a few seconds it will finally bleed off enough to get past TDC. There isn't any starting this thing. Even with the CR pushed in it has so much compression you can't pull it fast enough to start.

I think I know what your problems is, and mine also did it a bit. Your carb is leaking fuel into the crank case and you are getting hydraulic lock.

I re set the valve on my carb and it went away (lever was too high).

 

[TJ the Chainsaw Mechanic]

THIS^^^ On the tip of my tongue and beaten to say it. lol

Oh yeah...welcome aboard!

 

[Duane(Pa)]

Good call guys! That is what a forum is about...

 

[CR888]

Its not nice when a 660 bites back when cold starting. My OEM saw is ported by Randy and I'm careful when starting it. You want the piston just past TDC. I may check the metering lever in the carb to for good measure.

 

[MustangMike]

To get rid of the fuel in the crank case, pull the plug, put the piston at BDC, and rotate the saw 180 degrees side ways (to let the fuel flow through the transfers and out the plug hole).

Leave the plug out for another hour or two, clean it, and put it back and start it.

To fix the carb, pull the cover off (that is over the lever) and set the lever flush with the body of the carb (you just bend it). Mine was set too high from the factory. Other's have stated the spring has the wrong tension, but I did not have that problem.

 

[beaglebriar]

Welcome to the forum Larry.

When I can't get my saw started I holler for the wife.

 

[psuiewalsh]

I have had it happen but usually see fuel blowing out the exhaust

 

[MustangMike]

Depends on how badly it is leaking, and your muff set up.

 

[Larry B]

Well I guess I owe you guys all a tall chilled adult beverage. It wasn't hydo locked but I did just push in the CR and pull the rope literally about a hundred times and it started to not pull as hard on compression so I put the fuel line back on the carb and she started. Have to use the CR and pull like you mean it. Not sure about the next step, has a funky idle but I think I will put a couple tanks at 32:1 through it and then see if I want to swap the carb for OEM. I will probably go back to the single base gasket too. Just what I need....another toy. I already have a MS170 and an 031AV but I guess you can never have too much saw. Already got a guy want to put his Husky up against it. My plan is to run a 25" bar with a full chisel yellow chain with an 8 pin rim sprocket and rakers at .050. You think this thing will pull that OK? I have a modified dual port muffler and getting a max flow air cleaner. Anybody here filed the key and advanced the timing? See any difference. Back in the day I used to build 5HP Briggs racing engines for WKA. Since they went to the Honda clones haven't built anything special. Looks like I might be hopping something up again.
Again Thanks for all the help.
I may have one of the counter guys at my local Stihl dealer I buy parts at going to build one of these. Wonder what his boss will think?