Zama Carb rebuild questions

[Jmaffei]

Ok, putting a new carb kit in the 036 that runs good until it warms up then dies. Three questions, first one is I put in new impulse hose, fuel line, fuel filter and now doing carb, if the carb doesn't work what else could it be? Don't think it is tank vent as when open tank don't hear any pressure release.

Second question, all new parts were found in the carb except for this little spoon shaped thing, sorta like an old thermometer profile, pretty small, anyone know if I need this or where it goes?

Third question, do I need to unscrew the adjustment screws all the way out?

Thanks, James

 

[nmurph]

you symptoms could be caused by a coil going out.

the part you have is the welch plug.

you need to lightly seat them and then back them out about 1 turn each and tune from there.

 

[nmurph]

most people don't change the welch plugs bc they don't know what they are, why it might be needed, or how.-
trash can collect in this area
i use a very small bit or bur and CAREFULLY make a small hole. i then use a pick to pull it out. to re-install, place it over the opening with the curved side up. then take something small and blunt, and gently tap it until it is flat. some people seal this with nail polish. i never do. i think if you get them seated well and tapped flat it isn't necessary as the carb is not under much pressure.

 

[Jmaffei]

Thanks for the reply, yeah I figured out how to tune it, just didn't know if it helps to remove the adjustment screws for the cleaning. I will leave the welch plug alone as I heard you aren't supposed to mess with those really. I thought if the coil was messed up the saw just would not start, it will start and then go out due to the coil? Isn't there something about lifetime warranty on coils or not? Thanks, James

 

[Jmaffei]

Also, does the plasticky screen or the gasket go against the metal cover first?

 

[nmurph]

on the metering side, the gasket goes first, then the diaphragm, then the cover. on the intake side, the diaphragm goes against the carb body, then the gasket, then the cover.

some consider welch plugs optional. i think this is bc of fear of the unknown. they aren't too difficult.

yes, a weak coil will show up first when the saw is hot. let it cool and it will crank and run. shut it off when it's hot and it won't re-start until it cools.
you need to check the obvious stuff bf you start replacing coils unless you have access to one. replace the spark plug. check the lead. check the kill switch. i bought a 394 from a pawn shop and i thought it was having coil problems until i accidentally discovered that the plug wire was grounding against the cylinder. it would not re-start with the top cover on. one time i had the cover off and it re-started without a problem. that got me to looking for a ground issue.

 

[CGC4200]

Zama Technical Guide

Before I do a carburetor kit, I download and print diagram from carburetor
manufacturer, manual shows order of gaskets & diaphragms, how to check/set
metering lever, welch plugs & more.
I at least take out jet screws & spray carburetor cleaner in the holes.

 

[Jmaffei]

You've been real helpful murph, thank you. Just took her out and ran her for awhile and wouldn't die on me at all, I am going to fine tune the carb and whatnot but I think there was just a lot of junk built up in there. I probably could have gotten by just giving it a good cleaning as all the old gaskets and diaphrams looked in good shape. Makes me wonder if anyone really ran it much as it was made in 1994 and still looks good. Thanks, James

 

[JJay03]

Are there any rubber 0-rings under the welch plugs? I soaked my carb and did not remove the welch plugs just want to make sure I did not damage any rubber o-rings.

 

[pioneerguy600]

No rubber O rings under the welch plugs on any carb.
Pioneerguy600

 

[JJay03]

No rubber O rings under the welch plugs on any carb.
Pioneerguy600

Awesome thanks