Author Topic: More oil from 7900  (Read 898 times)

0 Members and 0 Guests are viewing this topic.

Offline Ducksnuff870

  • 6 cube
  • ****
  • Posts: 174
  • Karma: 16

Offline JP Terp

  • 3 cube
  • *
  • Posts: 7
  • Karma: 0
Re: More oil from 7900
« Reply #11 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!

Offline jar944

  • 3 cube
  • *
  • Posts: 16
  • Karma: 3
Re: More oil from 7900
« Reply #12 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




Offline 660magnum

  • Global Moderator
  • Nitro Hotsaw
  • *******
  • Posts: 6437
  • Karma: 249
  • For The Love Of Chainsaws
  • Location: NCO
Re: More oil from 7900
« Reply #13 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. 
We should share what we know... someone may learn...
That knowledge can live after us... and that "Pays It Forward".
Be all that you can be . . .

Offline jar944

  • 3 cube
  • *
  • Posts: 16
  • Karma: 3
Re: More oil from 7900
« Reply #14 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)



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.

Offline mdavlee .

  • Global Moderator
  • Nitro Hotsaw
  • *******
  • Posts: 1968
  • Karma: 171
Re: More oil from 7900
« Reply #15 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

Offline jar944

  • 3 cube
  • *
  • Posts: 16
  • Karma: 3
Re: More oil from 7900
« Reply #16 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.

Offline Cut4fun .

  • Administrator
  • Nitro Hotsaw
  • *******
  • Posts: 21874
  • Karma: 522
  • OHIO REDNECK Saw Repair Getter Done
    • Redneck Chainsaw Repair
Re: More oil from 7900
« Reply #17 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?
REDNECK Saw Repair Getter Done

Offline mdavlee .

  • Global Moderator
  • Nitro Hotsaw
  • *******
  • Posts: 1968
  • Karma: 171
Re: More oil from 7900
« Reply #18 on: February 09, 2015, 04:08:04 pm »
No that's Rich who goes by Poleman usually

Offline rayvil01

  • 5 cube
  • ***
  • Posts: 137
  • Karma: 19
Re: More oil from 7900
« Reply #19 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. 

 

Related Topics

  Subject / Started by Replies Last post
72 Replies
6953 Views
Last post August 30, 2015, 01:21:23 pm
by Cut4fun .
201 Replies
3789 Views
Last post October 17, 2014, 11:42:53 am
by EHP
29 Replies
3599 Views
Last post July 29, 2012, 08:03:35 pm
by Cut4fun .
7 Replies
713 Views
Last post September 15, 2012, 09:57:41 am
by farmboy
8 Replies
475 Views
Last post July 30, 2013, 09:20:17 am
by farmboy
28 Replies
2265 Views
Last post April 09, 2016, 02:02:55 pm
by computeruser
6 Replies
899 Views
Last post June 30, 2017, 05:39:15 pm
by Philbert
2 Replies
363 Views
Last post June 19, 2014, 03:32:20 pm
by farmboy
35 Replies
297 Views
Last post January 27, 2016, 03:28:50 pm
by Cut4fun .
3 Replies
285 Views
Last post December 08, 2017, 01:25:19 pm
by Tractorsaw1