Pro Mac 610

[ChainsawChick]

happy spring to all. I wrote a few months back about a Pro Mac 610 I ended up rebuilding for a friend after I bought a another running Pro Mac 610 as a potential parts saw . Well, apparently all I had to do was pull off some carb parts and then buy a carb rebuild kit from fayette equipment. I sent my buddy's back to him running well and just got around to rebuilding the carb on the 2nd saw for myself. What can you tell me about adjusting the air/fuel mixture to the proper ratio? I can't seem to get it adjusted right. It looked like it was going to start right up and then nothing. It is getting spark but I am going to go ahead and replace it anyways. Any advice you can give and pointing me in the right direction to seek help would be much appreciated. thanks

 

[Wood Hick]

Thanks for saving another one, they are good old saws. I have used one for many years, extensively when it was new. Mine is quite fussy if it sits for any amount of time, weather with no gas, Stabil in gas, or what. When you have it right for idle, it sometimes bogs down in the log. I kinda think they are like old Chevy trucks I've owned, they got to be running everyday to work right. I sometimes pull the cover off, loosen the right carb screw enough to allow me to shoot in a little fuel mix. ( just like the old Chevy ) Start the saw and then adjust right off of full throttle( as soon as you let go of the trigger) This saw is a great example of tuning by ear, when you own one, you get a feel for when it sounds right. It is not and never was a "pro" or precision saw, it is a contankerous old bugger! Good Luck!

 

[mbopp]

IIRR the starting point for the high and low jet is 1-1/2 turns out form the lightly seated position.

 

[2000ssm6]

I'm working on one for a friend. It was hard to start and didn't idle. I just turn both H and L in all the way and back them out 1 1/4-1/2" and go from there. Sounds like your plug is fouled from too much fuel....I may be wrong though....

 

[Al Smith]

They are not that cantankerous nor that hard to start if the thing is tuned correctly.You have to run them an RCH rich on the low speed .Wide open,as fast as they go,lean them just a fuzz until they just start to "4 cycle".

A little tip,more times than not,they develop hair line cracks in the fuel lines,often undetected.If the thing has a fouled plug,often times the oil pump is defective,sucks lube oil.If you shut them off hot and they do not start,the coil is overheating,blow the chips out of it.Keep that stupid little muffler screen cleaned out or they don't breath very good or just remove the danged thing and richen up the carb.Gives that old saw a whole different attitude.

 

[stihltech]

610

Weren't no pro saw, but I thought they did OK. Yes, with fuel and airleaks repaired, they started and idled well. Saw a lot of intake gasket leaks, just like on 10-10s.
Think it was there last attempt at a decent saw.

 

[ChainsawChick]

Getting there....

Trying a number of your suggestions...need a little clarification on one.

1. Al Smith-- what do you mean by ""RCH" rich on the low speed. Wide open,as fast as they go, lean them just a fuzz until they just start to "4 cycle"".?

We changed the spark plug and it isn't getting fouled so that is a relief there. We turned the screws all the way in and backed them off about 1 1/4-1/2 turns. It starts up, we are able to run it full throttle and adjust it to run ok, it runs for a little bit and then cuts out, so it looks like next we are going to try digging out that muffler screen since there weren't any chips in the way. It already seems to be running a bit rich so don't really want it any richer.

Also, when seating the needle and pin during the carb rebuild, which goes on first, the diaphram or the gasket?

thanks for the additional help.

 

[Tzed250]

Yeah...what does RCH mean...:hmm3grin2orange: :hmm3grin2orange: :hmm3grin2orange:

 

[KiwiTony]

I had what sounds like a similar problem a number of years ago.The saw choked up and stopped after maybe 1 minutes cutting or so.I yanked out the spark arrestor screen from the muffler,and it has never looked back since.Great little saw. Hope yours is as simple to remedy.

 

[Al Smith]

Yeah...what does RCH mean...:hmm3grin2orange: :hmm3grin2orange: :hmm3grin2orange:

Oh RCH ? Well that is a regional term I suppose but may be universal.Acronym for red , [word omitted], hair[read between the lines].Let me rephrase,set the low speed just a tad bit on the rich side,shall we say,just by a fuzz.

The wide open means as fast as it will go.Then richen up the high speed until the rpms fall off a bit and the engine just barely starts to load up from running a richer mixture,which burns a little slower.Not to worry because if it is tuned correctly,this "4 cycling" will turn into power,once the saw engine is under load.

 

[mbopp]

Runs then cuts out? I've seen the duckbill valve in the fuel cap turn gummy & stop the tank from venting. It'll run OK for a minute or so then quit.

 

[Brushwacker]

I donot remember if this saw has points,if it does your tuning might profit replacing points and condenser.
Your gasket goes first on the inlet needle side, then the pump diaphram , then the cover.
Seafoam gas treatment has worked wonders for me when gas varnishing has been a problem. I usually use about 1 ounce to a gallon. Let it sit several hours after you get it into your fuel system and you will generally have to readjust the carb if varnish was present.

 

[Al Smith]

I donot remember if this saw has points,if it does your tuning might profit replacing points and condenser.
.

This one uses a solid state ignition coil,no points .I have seen only one or two that were bad but of course I haven't seen them all.On occasion however they will over heat after being under load for extended periods of time .If this be the case they won't start for love nor money until they cool off.

 

[GASoline71]

Big, ugly, yellow, loud, heavy, gas hog of a saw. But it will run like a scalded dog when set up right.

Mine wears a 24" bar, and sees action quite regularly. Not a PRO saw... but a good old Mac.

Gary

 

[Log Splitter]

I hope you're not planning on using that 610 for carving, ChainsawChick! I had one for a few years and it was a heavy man-killer. Fortunately it broke a crank or a rod (never tore it down) and I got to upgrade.

 

[Al Smith]

To carve with one you would have to be built like the gov. of California back in his prime.

I've never seen a pm 610 break a crank,nor for that fact any of the 10-series saws.What I have seen is the exhaust side of the piston get burnt up,from a gummed up screen and snag the rings ,causing the piston to come apart like a dollar watch.The cost of repairs exceeds the value of the saw,in that case.

 

[Lou]

Oh RCH ? Well that is a regional term I suppose but may be universal.Acronym for red , [word omitted], hair[read between the lines].Let me rephrase,set the low speed just a tad bit on the rich side,shall we say,just by a fuzz.

The wide open means as fast as it will go.Then richen up the high speed until the rpms fall off a bit and the engine just barely starts to load up from running a richer mixture,which burns a little slower.Not to worry because if it is tuned correctly,this "4 cycling" will turn into power,once the saw engine is under load.

RCH is the finest measurement known to man!

 

[Log Splitter]

To carve with one you would have to be built like the gov. of California back in his prime.

I've never seen a pm 610 break a crank,nor for that fact any of the 10-series saws.What I have seen is the exhaust side of the piston get burnt up,from a gummed up screen and snag the rings ,causing the piston to come apart like a dollar watch.The cost of repairs exceeds the value of the saw,in that case.

I had the 610 a long time before there was an AS, so it was before I learned that working on old saws is fun. All I know is that it was running fine one second and the next it was dead. When I pulled on the starter, there was no resistance but you could hear something turning for a second or so afterwards. If I had to guess the crank broke right at the bearing on the starter side of the case.

I buried it in a 'landfill' at my timber farm, so I guess someday I could dig it up and find out what really happened to it. Who knows, someday they may be collector's items and I'll be rich.

 

[mbopp]

I got my 655 as a "won't run - no compression" freebie. Actually it was my dad's saw, he bought a 55R to replace it. The flywheel had loosened up & sheared the key on the crank. Neither the flywheel or crank looked damaged, so I replaced the key, put a carb kit in & went away happy.

The Monkey Wards 610 clone was another freebie - "needs a carb kit." Yeah, right. I pulled the muffler & there was aluminum smeared all over the piston rings and a nasty gouge in the cylinder. I found a parts saw on Evil Bay that had a good short block and got it running. This is my loaner & dirty jobs saw.

 

[Al Smith]

"

The Monkey Wards 610 clone was another freebie - "needs a carb kit." Yeah, right. I pulled the muffler & there was aluminum smeared all over the piston rings and a nasty gouge in the cylinder. I found a parts saw on Evil Bay that had a good short block and got it running. This is my loaner & dirty jobs saw.

That is exactly what kills most of them ,usually caused by a plugged screen,often gummied up by the diaphragm oil pump sucking bar oil into the crank case.Fact is,I just did a quick and dirty on one to keep it running that had this same problem.I told the owner to run 'til it blows because the parts cost more than the saw is worth.It may limp along for another ten years,time will tell.