Been fiddling with my -4911 pump looking for more rpms. I have turned the guide stud in all the way and can only get 3800 rpms, TDG mentioned in another thread that to swap the guide stud with one from a 6.2 pump the min/max governor needs to be changed as well. I assume the min/max gov. is what the guide stud goes into and "guides", is that correct? If so then I think that this may be a :badidea: as the -4911 spring is much stiffer when compressed than a -4544 off of a 6.2, unless I'm thinking about this backwards the stiffer springed gov. will demand more fuel at higher rpm's even if it can rev as high. However the more I think about all of this the more I think I'm wrong, that's why I need someone more educated to assist me...:help:

You could certainly do the swap, but not without a test bench to set it up, otherwise you'd never make it idle properly. Have to have the top cover off to set it, that would be tough and messy on the truck. The 4544 does have a much stiffer spring, but its a 2 spring governor, the 4911 has a 3 spring gov.
How many more RPM's are you looking for?

I'm not nessecarily looking for lots more rpms, but maybe up to 4200. I've had all the parts out of the pump while on the pickup before, so I could do it again. I was also worried about the idle, as I'm having problems with it now the way it is. Could the third little spring be added to the 4544 gov set do you think?

Nope, the guide stud is a bigger bore on the 4911, spring would be too big to fit.

Send it for a rebuild, and tell them you want the linkage gap set as short as possible (.125"). That will give you some more power on the top end, and more RPMs, and fix your idle problems, and cure cancer ;)

Other possibilities: (1) Look for a stiffer spring to go against the guide stud (preferred method) (2) Stretch the existing spring (3) Use a thinner lock nut on the guide screw.(4) Weld a small extension onto the existing guide stud.

All these methods are hypothetical alternatives and don't necessarily represent how I would do it.

I was screwing around last night and the 4911 guide stud will fit into the 4544 gov assembly... If there was anywhere nearby that could rebuild my pump I would do it, if the cost was right of course. Something else that has been on my mind, Can the 4544 be rebuilt with a 4911 head/rotor assembly? If so then I could just send out the 6.2 pump and wouldn't have any down time.

You would be looking at buying a new head and rotor, rebuild + new head is a grand easy. Your 4544 does have a non adjustable guide stud right?

DP is right too, take the nut off and shorten it on a belt sander or something, or pull out the spring and give it a little stretch, or find something to slide down the bore the guide stud fits to act as a shim.

Yeah the 4544 has a non adjustable stud. I figured that was going to be the answer $ wise for a rebuild. Seems to be a pretty common number from most vendors. I might have to try one of those other ideas later this evening. Thanks for the advice thus far as well.

If you can afford to be down with your truck for a day to have your 4911 rebuilt, just light/normal wear and tear should only run you 300-400, probable 5-600 exchange, 7-1000 if its in bad shape.

I was always under the impression that the head/rotor assembly should be replaced since the origionals were prone to have "hot" start problems? Maybe here in a couple weeks I'll be gone south for a while and can tear the pump off and send it somewhere. Any suggestions?

The old style, PN 29123 Head was prone to Hard Start Hot, yes, the update to 31505 head is not manditory, and if you don't have any problems than I wouldn't worry about it.

Don't know any shops in Colorado, sorry.

I'll be be down in Texas for the week I'll be gone, I bet you know of something down there.;)

You bet I do, Mike at Abilene Diesel, in Abilene will be able to help you out. Just tell him Travis sent you.

If I get my pennies together I might drop by, I'll be going through there headed to cross plains.