315 governor

[waukman]

I was told today by Michigan Cat that the governor spring 5f1941 is a discontinued part. they didn't show a cross reference either. I changed out the gov. bearings, pins etc last year. It helped with the speed stability but nothing drastic. I still get a 100 rpm hunt at any speed no load. With a slight
load (1/4 blade of dirt) the speed steadies out. I didn't see anything worn
with the rack or pumps. The nozzles are new. I thought the gov spring might
be spongy. Anyone have any ideas?

[edb]

Hi waukman,
it is possible you have flat spots on the gov. weight rollers (No 6) and/or indents worn into the sleeve (No 10), these cause sticking to the gov. operation.
IF you have the earlier type needle roller bearings for the gov. parts to pivot on the needle rollers wear grouves into the shafts and cause the symptoms you mention also. The gov. gets stuck in the grouves and it takes a decided change in engine--Gov.-- RPM up or down to overcome the resistance caused by the grouves to allow the gov. to move the rack and set the required steady RPM.
Be aware the later type steel bearings can get roughness worn into them also and cause sticky gov. operation, they need to be dismantled and polished to rectify same. I think centifical force throws the oil out of them and they run dry until the engine is stopped and drain back oil spills past them.
Goveners work by the gov. spring force verses the centrifical force created by the spinning gov. weights, the two are working against each other all the time to stay in a balanced condition. So if we have artificial forces at work--flat spots, grouves etc.-- you can see that the gov. spring or the centrifical force must change markedly to bring about the balance to the system.
I would look here before worrying about the Gov. spring as I doubt it would cause the symptoms you have.
I have attached a scan which may help.
Cheers,
Eddie B.

[waukman]

Thanks Ed for the input. I have the old style. The first time out I stumbled through it. I'll open the case up and and wear the bifocals this time I've got
doubts on the sleeve.

[waukman]

Hi Edb, I got my governor problem resolved. The spring was turned down on the thread collar( channel lock marks clearly present) this allowed about a 1/4" of dead travel on the terminal lever. I turned the spring back up to the set pin on the collar. Speed stability was right on(under 15rpm)
Strange that the service book doesn't mention where the spring is located on the collar.

[edb]

Hi waukman,
as far as I'm aware the spring is screwed on at the factory to give a specific tension at a specified lengths, this gives the gov. the designed characteristics. I never realy studied how the spring was retained in the adjusted position so it looks like you have found the pin as the located position for future reference for us all. Well done on the super sleuth work there.
From memory on the BB others have had the same problem before and we have come up with nothing other than the wear points I mentioned. Now I think there will be several Gov. Springs getting looked at to smooth out the hunting problem, although it seems yours had some outside help to get out of Spec., normally the two eyes at the spring ends are captive in operation and therefore the set position should not be able to change.
Maybe that Chinese bloke (guy) Sum Wun has fitted a higher ( Industrial/Gen. Set ) RPM spring and tried to adjust it to suit the TTT application, we'll never know I guess.
If you give me your machine details I can give you the Rack Setting Book High& Low Idle speed Specs.
Thank you for the update on your findings.
Regards,
Eddie B.

[waukman]

Hi Edb, Factory adjustment "only" could account why my parts book shows the spring as a assembly. I forgot to mention that I had to reindex the speed knob on the lock control ,apparently the lever linkage controls the amount of travel on the lock control in the shut off position. Too much travel
and the stop lever (4f17560) goes way over center and will not reset itself
on the next start up.(this can be reset by removing the lock control assy, then pry the stop lever while holding the slotted speed shaft downward).
This probably won't be a problem for most who still have the adjustable
linkage. On my machine the adj. linkage eyes were welded by someone, probably the same someone who tampered with the spring to compensate
for the linkage out of wack.

I have a 7u21836, you say you have the rack specs? Are all the lifter settings at 1.736" ? my project this next spring is to check the settings even though I don't have any timing or smoke,startup issues.
For everyones info the yokes are available (as of last year anyhow)from Cat
they are around $75.00 each.

PS, whats the term downunder for a f#*^up hammerhead mechanic. Uphere
in Michigan I call them Gomers.

[edb]

Hi waukman,
seems to me something is amiss with the shut off stop/detent flick over lever (4F1756 stop) as it should be shifted from L/I to Shut Off and vice versa by the 5F1579 lever as it passes to and from L/I to Shut Off, maybe the scans from the S.R.M. will help explain it for you. Maybe the L/I screw is a long way out of adjustment as it moves the slide and positions the Stop in to the required L/I position, from memory the main lever is a bit hairy fairy in the shut off position but as you suggest the main linkage--when adjustable-- takes care of it, wouldn't normally be noticed by virtue of the ratchet assem.
D4 7U21836 rack setting is 0.200", H/I= 1525, L/I= 500, Full Load= 1400, Gov spr. 5F6413, 51HP, & 4 blade fan.
Later machines 7U29424-37284 are H/I= 1745, F/L= 1600, Gov.spr. 5F1941, 58HP, & 6 blade fan, so may be the spring some one fitted and tried to adapt to yours was from one of these.
Lifter Setting is 1.736" +/- 0.004". Injection pump plunger length is 2.6575" - 2.6577" new, and should be replaced if wear exceeds 0.005", I would factor the wear measured into the individual lifter setting, for a hobby machine a bit extra wear should be ok?
Plenty of unprintable names readily come to mind for so called mechanics, you are being very polite with your "Gomer", came across plenty of these in my time in the Army also, especially at Rookie Training. "F*^#wit", and Richard Cranium= (D%*k Head), & Turkey, are a few of the well used one's in my local.
Hope this helps and not confuses,
Cheers,
Eddie B.

[waukman]

Hi again Edb. Mystery resolved on the shutoff lever. I forgot to mention that
the low idle thread hole is stripped out. someone put a bolt in upside down with a nut on top. by accident the oval top cover holds the bolt in location for low idle speed. ( now I'm guilty of one of those "o by the way" details after the fact. I get these on half the jobs I go on or so it seems 0

thanks again for the setting info

[edb]

Hi again waukman,
that is how the LI adjuster is, it has a nut held on top with a roll pin thru it, it is supposed to adjust the slide up and down to shift the flick over levers' position which in turn sets the low idle and shut off positions.
I was hoping you could tell this from the pix of the LI and Shut Off positions in last post.
Cheers,
Eddie B.