McCulloch Chain Saw 310 No Start !!!

[OldDiyer]

So heres the story, Got this saw as a no start saw is in like new condition so thought it would be worth getting it back to running condition. For sure it did not start so this is what I have done.

Changed all fuel, fuel lines, filter, new plug replaced all carb internal gaskets and diaphragms,flushed carb more than once. Did get it to start once but didn't get the carb set so let it set till the next day but than again would not start. Saw has good spark and also found that with a bit of starting fluid it will run but just can't get the thing to run on its own. After reading thru this site maybe the PrimeLine Gasket set may not be up to par to be using?
It is a Zama C1 1702A carb and they don't seem to be available anymore so can't get a new one. Just has me confused as to what I may be missing or not doing right. It also has good compression. Best I can figure is it is still fuel related but can't get it to run. Did a vaccum test on carb and it does hold vaccum if that means anything.
Hoping that someone has an idea as to what I am missing. Thanks

 

[bertsmobile1]

First, the Prme Line kit will be fine, provided that it is the right one for your saw.
Second did you test the crankcase seals ?
Buggered seals manifest themselves as starting problems .
Third , did you pull the muffler & check for bore damage ?

The most common reason for an almost new looking saw not starting is destroyed bore from running an strait fuel
Runs for about 10 to 30 minutes on the assembly lube then stops, forever.

 

[OldDiyer]

I can pull the muffler and see what the bore looks like. Don't know how to check the crankcase seals. Still in the dark as to why I did get it running for a while but than the next morning it would not run again. If I can I will look into the exhaust check today. I did look into the intake side of the piston and cylinder and that looked good but will look at the other as suggested and will get back to you.

 

[StarTech]

Well it can be ordered gaskets and saw flooded out out overnight. Also it could be a failed kit too. I had one those rare cases recently with an OEM Walbro kit cause by the customers fuel mix. It destroyed the metering diaphragm. So I put in another diaphragm and as sent the saw back; I also included two packs of the Pro multi mix oil that I sale along. Got a report back a couple weeks later that everything was fine. I still do not know the customer used for fuel mix.

About the only thing vac testing can test for on this carburetor is if he fuel pump side is sealed. Doesn't test for a leaky valve as that is done using pressure and it should pressure for several minutes without leakage.

Crankcase test require block off plates (or rubber pieces of inner tube) to seal the intake and exhaust ports. If impulse port is used, it too need blocking. Then using a modified spark plug pressurize the engine to 7 psi and check for down should this pressure for several minutes without leakage. And there is the vacuum test of about 15 inches of vacuum using the method of testing and leakage rates. Seals can leak under pressure or vacuum. Leakage under pressure can found using soapy water spray on the seals and any mating gaskets and it bubble up where there is a leakage.

Note OEM block plates have nipple installed so you don't need a modified spark plug or if the engine has separate impulse port then it is used.

Also after kit installs and tuning there are times the unit will need re-tuning a few days later as things get settled in with fuel mix used. Most times it is only a slight re-tune but does happens.

And yes the Zama C1 17-02A is no longer available nor none it supersedes. It appears to be one of the first carburetors that Zama made since the repair kit is RB-1

 

[upupandaway]

So heres the story, Got this saw as a no start saw is in like new condition so thought it would be worth getting it back to running condition. For sure it did not start so this is what I have done.

I got a McCul 510. the motor is similar to yours. First, loosen the gas cap and try it- your carb should only have 1 hose from the tank. Maybe the cap is plugged and not venting.

Mine would run but i couldn't restart it. I found the plug was wet - running rich. I then experimented closing the high mix screw a hair at a time until It would run\restart fine.

Mine for the life of me, won't start without a spray of starter choke or not- but it restarts fine. Being i only use it occasionally cutting some wood and not for a job, I live with it.

With all of this, I bought a carb rebuild kit. It helped alot. Maybe you should consider the same. I read mine was made 1980+/- Yours is not much younger.

 

[OldDiyer]

OK so I pulled the muffler and piston, cylinder walls all look like new. Before doing this I could start it with starting fluid but still would not run on its own fuel supply. I check the fuel cap and it is venting.
So now I am thinking of just ordering the rebuild kit instead of just the gasket diaphragm set and going thru the carb another time with the other replacement parts.
Could it be that spraying with carb cleaner that something in one of the ports got wrecked? When I watched a a Zama rebuild video they say not to spray directly in to any of the holes but others I saw this wasn't a problem?
Is there some way of checking the pulse on the pulse line? It is mounted directly to to block. I also pulled the carb again and both chambers have fuel in them. Thanks

 

[upupandaway]

OK so I pulled the muffler and piston, cylinder walls all look like new. Before doing this I could start it with starting fluid but still would not run on its own fuel supply. I check the fuel cap and it is venting.
So now I am thinking of just ordering the rebuild kit instead of just the gasket diaphragm set and going thru the carb another time with the other replacement parts.
Could it be that spraying with carb cleaner that something in one of the ports got wrecked? When I watched a a Zama rebuild video they say not to spray directly in to any of the holes but others I saw this wasn't a problem?
Is there some way of checking the pulse on the pulse line? It is mounted directly to to block. I also pulled the carb again and both chambers have fuel in them. Thanks

While people say carb cleaner\starting fluid will ruin motors, only if u run it for 10 min straight maybe. I use it all the time when i fiddle with stuff and have never ruined any. If I DO spray it numerous times, i just add some motor oil to the cyl itself JIC before going back and trying to start it. I especially did that when I first got my original FS80 and trying to make out exactly how the Japanese TK carb worked.

On mine.... the carb doesn't have a tube that air draws fuel from. It has a small "pad" where the gas evaporates off of like the carb in my 70'ish snapper briggs. Well, on mine, it is clogged or something but i drilled a 1/32" hole through mine and it works. Soaking the carb did nothing for me. Just saying....

 

[slomo]

Saws sit for untold days/years. Fuel will varnish up inside the carb. Carb needs heat and a good solvent soaking to unclog. Wife's dishwasher on hot pot scrubber mode works great.

Just saying most likely it was never drained prior to putting away. Carb is all gunked up.

slomo

 

[bertsmobile1]

OK so I pulled the muffler and piston, cylinder walls all look like new. Before doing this I could start it with starting fluid but still would not run on its own fuel supply. I check the fuel cap and it is venting.
So now I am thinking of just ordering the rebuild kit instead of just the gasket diaphragm set and going thru the carb another time with the other replacement parts.
Could it be that spraying with carb cleaner that something in one of the ports got wrecked? When I watched a a Zama rebuild video they say not to spray directly in to any of the holes but others I saw this wasn't a problem?
Is there some way of checking the pulse on the pulse line? It is mounted directly to to block. I also pulled the carb again and both chambers have fuel in them. Thanks

Simple check is to slip the carb off leaving the fuel lines inplace , turn it sideways and blow air through the carb.
If fuel sprays out the engine end then the carb is working
If no fuel the carb is clogged.
Now for the crunch
some of the carbs have check valves and if left with fuel in them will gum up .
Once this happens the carb is scrap metal as the check valves are not a replacement part .

 

[OldDiyer]

Back again just to let everyone know whats up. I removed the carb again and am going to order the rebuild OEM rebuild kit and redo the rebuild again. I will for sure do the clean up again just in case I missed something. Well keep you posted as to how this comes out and again Thanks for all the advice. I haven't given up yet on this saw. Ha Ha