Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Husqvarna => Topic started by: 2manyhobbies on October 07, 2013, 07:28:55 pm

Title: 3120xp project saw
Post by: 2manyhobbies on October 07, 2013, 07:28:55 pm
Hi everyone, I am new to the forum... so hello from NC!

I recently bought a 3120xp project primer bulb model - I bought it as a non-running saw but got it up and running quick enough.  Both the piston/cylinder and carburetor were changed by the previous owner about 6 or 7 years ago and the saw has not been run since then.  Looking in the cylinder it matched his description.  The problem is that the original Walbro WG2 was replaced by a WG8 (WG 8  620) which is a choke carb with no "high" adjustment.  From what I have found this is for a later model EPA Husky.  My other issue is that I cannot get it to idle down under ~2,800 - 2,900 RPM.  Any suggestions?

I would like to find an original carb for the saw so that I can keep using the primer bulb (which I will need too.)  Anyone here have one for sale, or know where I can get one?

If I cant find a carb with high adjustment how do I make sure that the high adjustment (that I dont have) is set correctly?  In the past I have been playing around with the big Homelite C series saws (C-51, C-72, and a C-9) which have fully adjustable carbs. 

Any help you guys can give me would be appreciated. - Brad
Title: Re: 3120xp project saw
Post by: Cut4fun . on October 07, 2013, 07:51:06 pm
The WG2 and primer bulb will be pretty tuff to find. 

You can have a H side put in for about $25-$35
Title: Re: 3120xp project saw
Post by: sharkey on October 07, 2013, 07:53:49 pm
>>My other issue is that I cannot get it to idle down under ~2,800 - 2,900 RPM.  Any suggestions?<<

By opening the low side carb jet you will slow it down. 
Title: Re: 3120xp project saw
Post by: 2manyhobbies on October 07, 2013, 08:22:15 pm
Thanks for the quick replies!  Who is it that is modifying the carbs?  Or is there an instruction on doing it?  I do have a machine shop at my disposal.  One of my hobbies is building model hit n miss engines.
Is it normal for a carb with only a low adjustment to be running at 2.5 to 3 revolutions off from the seat?  Does the 3120 ignition have an electronic rpm limiter? 
Title: Re: 3120xp project saw
Post by: Cut4fun . on October 07, 2013, 08:29:41 pm
Terry Landrum would be the most likely to do it for you. Username tlandrum here.
 The other 2 I know are racesaw builders and stay busy with other stuff.

You could probably do it yourself easily. But for 25-35 I just say here you go. Being I have no skills like that.
Title: Re: 3120xp project saw
Post by: Cut4fun . on October 07, 2013, 08:32:44 pm
I had a rev limited 3120 by coil. Threads here somewhere.   Type 3120 in search. Bunch of info.

Had no H side carb on a stocker and cant remember.  Sure you dont have a air leak?
Title: Re: 3120xp project saw
Post by: 2manyhobbies on October 09, 2013, 11:52:51 am
Well... You hit the nail on the head, I have a craccked intake plenum.
Brad
Title: Re: 3120xp project saw
Post by: Cut4fun . on October 09, 2013, 12:39:44 pm
Nice find.  Just sounded like air leak to me.  Thanks for letting us know.
Title: Re: 3120xp project saw
Post by: Cut4fun . on December 12, 2013, 02:23:36 pm
Hamish posted this info and felt it needed saved before lost.

Quote from:  hamish
You can adapt 530038874 to work.  Its the older style primer bulb found on the Mondo series of trimmers.