Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Dolmar Makita => Topic started by: Thomas Barber on July 10, 2015, 05:18:41 pm

Title: makita 6421 adjustment
Post by: Thomas Barber on July 10, 2015, 05:18:41 pm
I have a 6421 Makita when you are making a cut it sounds like your hitting a rev limiter. Is that a carb adjustment ? I did manage to clean all the epoxy from the carb . But I didnt want to screw with it yet.
Title: Re: makita 6421 adjustment
Post by: 660magnum on July 10, 2015, 07:10:37 pm
The 6421 is rev limited via the ignition coil
Title: Re: makita 6421 adjustment
Post by: Thomas Barber on July 10, 2015, 11:10:11 pm
can that be adjusted buy tuning the carb ?
Title: Re: makita 6421 adjustment
Post by: man of stihl on July 11, 2015, 05:30:50 am
can that be adjusted buy tuning the carb ?
No.
 
Title: Re: makita 6421 adjustment
Post by: 660magnum on July 11, 2015, 05:53:48 am
I have a couple 7900 Dolmars and they are the same family as your  Makita 6421. I keep the 7900 saws rich enough to where they never get to the rpm limiting function of the coils.

My older son and his friend used them to reduce a huge ash tree a few weeks ago and I never heard the saws go into ignition limitation?
Title: Re: makita 6421 adjustment
Post by: Cut4fun . on July 11, 2015, 10:21:23 am
Fatten the saw up WOT to where it isnt hitting limiter or tune in the wood.  Pick one
Title: Re: makita 6421 adjustment
Post by: jmester on July 11, 2015, 10:23:03 am
I have found that saws with limiters are easiest to tune in the cut.
Title: Re: makita 6421 adjustment
Post by: Eccentric on July 11, 2015, 04:00:36 pm
Tune it in the wood for sure.
Title: Re: makita 6421 adjustment
Post by: Thomas Barber on July 11, 2015, 04:03:17 pm
ok will do . Thanks for all the replies.
Title: Re: makita 6421 adjustment
Post by: Thomas Barber on July 12, 2015, 10:20:32 am
I sharped the chain and tried it again it runs great
Title: Re: makita 6421 adjustment
Post by: dannyupsolate on July 13, 2015, 12:52:53 am
there may be mixture limiter caps on your carb they are  pollution control.  Many people find a way to defeat the mixture limiter caps to get the mixture rich enough for a long life saw .the rev limiter is electronic inside the coil. thanks for all your hard work on a great distro Thomas
Title: Re: makita 6421 adjustment
Post by: 660magnum on July 13, 2015, 01:22:08 am
Depending on what year they were made, some of these had the needle valve cavities filled with a metalized epoxy where you couldn't adjust the needles. You had to buy a new carb.

Most had tabs on the needle valves that could be removed.