What to ask when looking at a Jubilee?

GabeTX · Apr 5, 2005

I replaced the points and condensor, and the engine now (eventually) idles quite well. I'd even say it purrs. It purrs like a 52 year old cat with a bit of rust and a cold, but it's a purr none the less. /forums/images/graemlins/grin.gif

However, I think there were multiple problems at work, because another behaviour is now apparent: after I adjust the speed with the throttle, it oscillates (slows, revs, slows, revs, slows, revs ...) until it eventually converges on a steady state. This only seems to happen under no-load conditions and when the engine is running less then 1200-1000 RPM's or so. I can see the governor rod moving back and forth as this happens.

soundguy: Other then really basic stuff like oil changes and simple maintenance--on an '89 corolla--I have no mechanical experience. So the basic information on the points was appreciated! I wasn't even sure how to accurately turn the engine by hand. I've been learning quite a bit, these last few days.

jinman: One of the first things I did when I got it was to spray some carb cleaner in the carb. The fluid that poured out was significantly thicker then what went in--it looked and flowed more like warm maple syrup then what was spraying out of the can. I'm thinking this is verification that the carb is pretty dirty? Or is that normal?

I've already adjusted the idle and the main screw according to the operators manual and Soundguy's earlier advice. I'll take a look for that drain screw, and clean off the outside and look for anything obvious.

I've now replaced all the easily replaceable ignition stuff (except the coil): plugs, wires, cap, rotor, points, and condensor. All gapped correctly.

But, it certainly does have plenty of power to drive the 6' brush hog, and it doesn't stumble under load ('cept when I run over something I shouldn't have /forums/images/graemlins/blush.gif ). The no-load rev oscillations add character. /forums/images/graemlins/smile.gif

Soundguy · Apr 6, 2005

Jinman brought up a good point about vacume leaks. An easy way to check this is to get the tractor out of the barn and inthe fresh air.. get a plumbers propane torch out Start the tractor.. get it idling real low.. turn the torch on but don't light it. Wave the flow of propane around the carb and carb to manifold connection.. if idle changes and is repeatable.. you have a vacume leak.

Soundguy

Soundguy · Apr 6, 2005

Have you adjusted the idle jet. On those MS carbs.. the idle circuit only works int he low hundred rpm range. it's possible that you have a lean idle jet and it keeps hunting back and forth between the main circuit and idle circuit. Turn the idle circuit up a tad. remember that it is backwards.. in to enrich on the idle circuit. Where the main circuit is out to enrich.

Other than that.. sounds like you have it going good.

Sounds like carb was WAY dirty.. that could account for the problems too.

A real rebuild wouldn't hurt.. but try running some carb cleaner thru the gas for a few tanks to see if it helps.

If you have no mencanical exp.. a carb rebuild will be way fun.

Good luck.

Soundguy

GabeTX · Apr 12, 2005

I hate to bump this again, but another minor (hopefully) issue has cropped up...

After working it a few times, the hydraulics seem to have changed: There's now a groan that comes from the back end (definately the back and not the pump) when I lift something heavy, and the lift position fluctuates slightly, even when there's no load. If I set a position on the hitch, it will go to that level no problem (even if cold/at idle/with a heavy load), but once it reaches there it will occaisonally drop an inch or so and the immediately rise back up.

It doesn't drop fast when I turn the engine off--I can raise the 6' brush cutter with chain guards (~750 lbs?) all the way up, turn the engine off, and then stand on the far end of the brush hog (~150 lbs) and it falls too slowly to perceive.

I've changed the fluid--the stuff that was in there was dirty, but looked cleaner then anything else I've drained from the tractor. It did seem to have some air in it, but I'm not familiar with hydraulic systems so I don't know if it was an abnormal amount. I replaced it with TSC's universal trans/hydraulic tractor fluid stuff (NH 134D was listed on the back of the bucket, so I know I grabbed the right stuff...).

An additional odd thing about the hydraulics on this thing is that it looks like a non-standard valve was added. On the top of the pump there's a short piece of pipe that comes up an inch, goes into right-angle pipe, goes horizontal a few inches, and then terminates in a brass valve. The parts catalog seems to show only a bolt in the top of the pump? /forums/images/graemlins/confused.gif

It's not that bad a problem--if I really need the lift to stay stationary I can always shut off the engine (this worked when I used the boom pole to put cross members on a fence brace...), so if fixing it involves major and the current state isn't damaging anything I might put it off until the winter, when I plan on trying to rebuild the carb... /forums/images/graemlins/laugh.gif

Soundguy · Apr 12, 2005

Here is where the hyds really differ between the 8n and NAA. not only is the pump in a different location.. but the valving is totally different. 8n uses a valve that controllsintake and exhaust.. NAA uses an unloading valve. The 'bobbing' or 'correction' you mention is common. I 'think' there may be a section on it in the fo-19 manual.. but I don't have mine handy. Could be a sticky valve. A real leaky hyd piston would do it too.. but that's not your problem it sounds like..

The 134 equivalent fluid is perfect to use.

If their had been air inthe system.. it would eventually purge out of the line/manifold.. etc.

As for the extra brass valve.. perhaps it was there for a (rare)dealer installed live pto option.. every now and then you see them. The live pto option was a hyd operated clutch pack.. fluid pressure actually came from a line plumbed out the pump.. and over the top of the tractor, and then back to the left side inspection cover... perhaps this is the remnants of one?

Also possible it was an owner installed line for some sort of remote setup.

Sanap a pic and i ight have a better idea.

if you don't have a fo-19 manual.. I'll look in mine tonight.. I also have the dearborn service manual for the 53/54 model.

Soundguy

Soundguy · Apr 12, 2005

I forgot to add one thing.. make sure you are in position mode.. not draft mode.

Soundguy

jinman · Apr 12, 2005

( Also possible it was an owner installed line for some sort of remote setup. )

Could it be that someone installed this as an easier way to prime the pump? If the system is leaky, these pumps can lose prime. I have loosened the plug to let the air out several times to get mine going. /forums/images/graemlins/smile.gif

GabeTX · Apr 13, 2005

Doh! I didn't think to check the FO-19 manual for a hydraulic troubleshooting section. I'd thumbed through the engine bits, and it seemed like a fairly terse R&R guide more then anything, so I didn't think to check it.

In any case, it suggested looking for leakage around the cylinder through the filler plug (didn't see any) and then removing either the PTO engagement lever cover or the equivalent on the other side (with the hydraulic dipstick in it) to check to see if the valves were leaking. Naturally, the socket for those bolts was one of the only ones missing from my set, so I'll wait to look at those until I get a chance to buy another. If it's not hurting anything, I won't be in a rush. And the movement isn't very great, especially with the brush hog on the back. The boom pole was just exagerrating it a lot due to its length and light weight...

Thanks yet again!

Soundguy · Apr 13, 2005

( Could it be that someone installed this as an easier way to prime the pump )

Very well could be. The vane pumps were the worst about loosing prime. Course.. this also led to premature wear ont he pumps too..

Soundguy

GabeTX · Apr 28, 2005

Ack! Hate to bump this again, but I have yet another stupid question /forums/images/graemlins/blush.gif about the temperature guage. Hopefully it's not a big deal, but I thought I'd check to put my mind at ease.

Today I mowed, and while I was mowing the temp gauge needle got real close to the red area. It was maybe 1/8" away from it at its peak. It never actually entered the red, or even touched the line, but it came close. It was about 90 degrees when I mowed; the hotest I've worked it in yet. Previously it only got up to about 2/3rd's of the way into the green.

I checked the fluid and it wasn't particularly low (maybe 3/4" below the top of the tank?) and looked normal, except for a piece of clear silicon-like material floating at the top (this is what scared me the most! /forums/images/graemlins/ooo.gif I removed it with a pair of needlenose, and didn't see anything else in there).

So.... Acceptable behaviour for the Jubilee, or something I should look into? /forums/images/graemlins/crazy.gif