Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Dolmar Makita => Topic started by: KilliansRedLeo on April 09, 2014, 10:38:21 am

Title: More oil from 7900
Post by: KilliansRedLeo on April 09, 2014, 10:38:21 am
Trying to get my 7900 to deliver a little more oil. Does anyone know if there is a pump from another model (9000 perhaps) that will work and deliver more oil?
Title: Re: More oil from 7900
Post by: 660magnum on April 09, 2014, 10:56:56 am
Other than buying a complete 9010 assembly and adapting it to your 7900?

They are made a lot alike but the part # are different
Title: Re: More oil from 7900
Post by: 660magnum on April 09, 2014, 11:01:50 am
I went and looked up the pump for the 9010

http://www.ebay.com/itm/genuine-Makita-Dolmar-024-245-100-automatic-oiler-assembly-PS9000-DCS9010-saw-/121303238670?

It looks much like the one for the 7900
Title: Re: More oil from 7900
Post by: 660magnum on April 09, 2014, 11:07:51 am
I see the 9010 has a different adjusting screw.

The 9010 looks to be a full time oiler but that has nothing to do with the pump. I bet they could be interchanged.
Title: Re: More oil from 7900
Post by: KilliansRedLeo on April 09, 2014, 11:36:57 am
Thanks Jim, I have a new 9000/9010 pump in stock. I will mess round with it as soon as I get my 'honey do' stuff done!
Title: Re: More oil from 7900
Post by: Ducksnuff870 on April 10, 2014, 08:20:08 am
let us know how it goes!!
Title: Re: More oil from 7900
Post by: KilliansRedLeo on April 10, 2014, 08:37:12 am
Back burner job, it is my own saw. Have customer work that comes first. I will let everyone know how it goes.
Title: Re: More oil from 7900
Post by: rayvil01 on April 10, 2014, 10:00:33 am
I stumbled into a webpage a while back where a guy was modifying 7900 oilers so they would handle longer bars.  No idea what he's doing.  And now I can't relocate that web site.  He was charging $50 if I recall correctly.

Looking forward to your report.
Title: Re: More oil from 7900
Post by: KilliansRedLeo on April 10, 2014, 10:13:51 am
Found the guy, hotsaws101, l believe it is Jack Belar in WA but not sure. 55$ to mod and mail back.
Title: Re: More oil from 7900
Post by: Ducksnuff870 on April 14, 2014, 07:39:47 pm
https://www.youtube.com/watch?v=lAnZ6b2YjSw
Title: Re: More oil from 7900
Post by: Ducksnuff870 on April 14, 2014, 07:45:10 pm
https://www.youtube.com/watch?v=VXVPMB9SE_s
Title: Re: More oil from 7900
Post by: JP Terp on April 15, 2014, 07:32:52 pm
Do you have an address or contact info for hotsaws101?   I'd love to get my 7901 to oil more!
Title: Re: More oil from 7900
Post by: jar944 on February 09, 2015, 11:33:46 am
Its a simple mod if you have some tools
Cut the pump rotor angle to 30 degrees (20 is stock) and increase the height on the adjusting "screw" nub. In my case I just made a new screw

(http://img.photobucket.com/albums/v695/jar944/rps20141014_211800_zpsvvvnuthd.jpg~original) (http://smg.photobucket.com/user/jar944/media/rps20141014_211800_zpsvvvnuthd.jpg.html)

(http://img.photobucket.com/albums/v695/jar944/rps20141013_221325_zpsauy7jaot.jpg~original) (http://smg.photobucket.com/user/jar944/media/rps20141013_221325_zpsauy7jaot.jpg.html)
Title: Re: More oil from 7900
Post by: 660magnum on February 09, 2015, 11:44:21 am
Good post on modifying the pump. We needed that.

In rebuilding the oil pump on my year 2006 7900, the little end piece of the plastic adjusting screw was worn off.

So even if you are not going to modify your rotor angle or make a new adjusting screw, It would be a smart move to put a parts kit in your pump if the saw has much use at all on it.

All the later model pro Dolmars have the same design oil pump. The 50cc saws use the black adjusting screw. The ones bigger than a 7900 have a steel adjusting screw. 
Title: Re: More oil from 7900
Post by: jar944 on February 09, 2015, 12:04:25 pm
If you were wondering the difference was between the white and black adjustment "screws" in the rebuild kit, Its the "nub" offset (about .020".) It allows less movement of the pump rotor and less total flow (in any screw position)

(http://img.photobucket.com/albums/v695/jar944/rps20141015_201200_850_zpsxva3iqnw.jpg~original) (http://smg.photobucket.com/user/jar944/media/rps20141015_201200_850_zpsxva3iqnw.jpg.html)

Also regarding the 30 degree angle modification to the rotor, on max output it will about use 1 tank of oil for every .75 tanks of fuel. So watch you don't run out of oil.
Title: Re: More oil from 7900
Post by: mdavlee . on February 09, 2015, 12:44:08 pm
Glad you made it over here to share. When you going to make a production run of the control bolts? :D
Title: Re: More oil from 7900
Post by: jar944 on February 09, 2015, 02:58:21 pm
Glad you made it over here to share. When you going to make a production run of the control bolts? :D

lol As soon as my wife runs out of things I need to do first.
Title: Re: More oil from 7900
Post by: Cut4fun . on February 09, 2015, 03:08:59 pm
Nice info. Thank You for joining and sharing with us.


Mike is this the guy doing carb stuff too?
Title: Re: More oil from 7900
Post by: mdavlee . on February 09, 2015, 04:08:04 pm
No that's Rich who goes by Poleman usually
Title: Re: More oil from 7900
Post by: rayvil01 on February 09, 2015, 05:34:55 pm
Even without a milling machine the rotor adjustment looks do-able with any number of tools.  The screw is another matter. 

Great info. 

Interesting that these saws are light on oil.  Every old Dolmar I ever worked on shot oil like a fountain. 
Title: Re: More oil from 7900
Post by: 660magnum on February 09, 2015, 07:15:56 pm
The 7900 is normally limited in using a bar longer than 28" unless you are cutting clean green wood.
Title: Re: More oil from 7900
Post by: jar944 on February 09, 2015, 08:07:05 pm
Even without a milling machine the rotor adjustment looks do-able with any number of tools.  The screw is another matter. 

Great info. 

Interesting that these saws are light on oil.  Every old Dolmar I ever worked on shot oil like a fountain. 

You may be able to modify the OEM screw by removing the nub and then drilling a hole in its place. Then epoxy in a section of tig rod as a new taller nub.
Title: Re: More oil from 7900
Post by: rayvil01 on February 09, 2015, 08:46:43 pm
Good idea.  Well worth a try.  Thanks for that.
Title: Re: More oil from 7900
Post by: farmboy on February 09, 2015, 09:18:42 pm
Cool!!!!  I have a spare OP I'll probably try the screw in he nub. 
Thanks much,
Shep
Title: Re: More oil from 7900
Post by: jar944 on February 09, 2015, 10:32:39 pm
Cool!!!!  I have a spare OP I'll probably try the screw in he nub. 
Thanks much,
Shep

If you use a screw it needs to be about the same dia as the nub or you may loose flow.
(http://www.modernpumpingtoday.com/site/wp-content/uploads/2014/08/Moving2.jpg)
Title: Re: More oil from 7900
Post by: Ducksnuff870 on February 18, 2015, 10:59:36 pm
Awesome!