rotor play

Mike in Ohio · Jun 16, 2018

How much free play should there be in the distributor on a WD45? The timing is jumping all over the place. With a timing light the fire mark is lighting up an inch on either side of the center of the hole in the bellhousing. No real pattern to the swings. Seems like the rotor has a lot of play.

Also, what brand of ignition parts do you guys use and where do you get them? I have using NAPA or tractor supply, haven't been having good luck with either lately.

Thanks

Bob Bancroft · Jun 16, 2018

Often the advance springs corrode, and just plain wear out, and break. Can you see a definite timing change by going from slow to fast?

Mike in Ohio · Jun 16, 2018

(quoted from post at 16:15:27 06/16/18) Often the advance springs corrode, and just plain wear out, and break. Can you see a definite timing change by going from slow to fast?

It doesn't seem to matter about rpm, it just bounces semi randomly, the mark moves about 2 inches, an inch either side of the center of the opening. It seems to advance then retard but not every time it flashes. Plugs were black with some soot on them when I checked them, points were a bit pitted, I cleaned both up and set the gaps per my service manual. I put in a new rotor that I had here already, but it is different from the old one, the contact point on the rotor is very long, kinda looks like a scimitar, old one was squared off, about 1/4 or 5/16 wide. Plugs are AC295s.

A little back story, this tractor spends its winters in an extremely damp building. It was running just a bit rough when we put it away last winter, now it misses badly. The other problem I found today is that the load adjustment (bottom adjusting screw)on the carb is very loose and moves around to the vibrations of the motor. I think it may be time for a rebuild, don't know when it was last done, we've had the tractor for about 10 years or so.

We addressed the damp building this spring, hopefully that won't be a problem from now on.

Mike in Ohio · Jun 16, 2018

The rotor seems to move about 1/4" before I feel the spring tension. here is a pick of the new rotor.

old · Jun 16, 2018

The rotor should fit down nice and tight and you should have to really work hard to make it move any

Mike in Ohio · Jun 16, 2018

The rotor sits down nice and tight, the whole shaft moves easily, enough that the tip of the rotor moves about 1/4" with my fingers. I just pulled off the rotor and the shaft moves easily. Starting to think the dist drive gears are worn, is there any way to adjust them, or should I start looking for a new distributer?

old · Jun 17, 2018

I'd pull the distributor after making sure the engine is at TDC and mark where the rotor is pointing. I would then check that the drive gear lock is not bad and that the gear it self is not bad. Been to long ago that I had one of those out to remember exactly how they are set up

DrAllis · Jun 18, 2018

Remove the rotor and plastic cover to see the points. Rotate the engine until the points are OPEN. Now, wiggle the rotor shaft. Technically, the points shouldn't move at all. Sounds like a worn out brass bushing inside the distributor body that supports the rotor shaft.

YTSupport · Jun 18, 2018

When I disassembled my G149 (conceptually identical distributor and governor relationship), I removed the distributor and the drive gears were shot. It had a lot of slop in it, but had been running fine, nothing like you describe. I ended up replacing the distributor and the governor. I can imagine that between both gears being so worn, you might get that much play, so maybe that's what is causing the slop, but not necessarily causing the running issue. After seeing how absurd the wear was on these, I guessed that over the years, timing it compensated for the wear, but unless it got so bad that it jumped teeth, it would be fine since it was under load all the time. The governor gear was worn also. The distributor gear was nearly a knife edge as you can see, and it's supposed to be about 1/16th of an inch of gear tooth. With say an 1/8th inch of movement at the gears, it would probably translate into a wide arc at the tip of the rotor.

The photo compares a worn gear on the top, with a shot gear on the bottom. Pulling the distributor would tell you quickly if you have a similar problem.

Mike in Ohio · Jun 19, 2018

(quoted from post at 11:00:36 06/18/18) When I disassembled my G149 (conceptually identical distributor and governor relationship), I removed the distributor and the drive gears were shot. It had a lot of slop in it, but had been running fine, nothing like you describe. I ended up replacing the distributor and the governor. I can imagine that between both gears being so worn, you might get that much play, so maybe that's what is causing the slop, but not necessarily causing the running issue. After seeing how absurd the wear was on these, I guessed that over the years, timing it compensated for the wear, but unless it got so bad that it jumped teeth, it would be fine since it was under load all the time. The governor gear was worn also. The distributor gear was nearly a knife edge as you can see, and it's supposed to be about 1/16th of an inch of gear tooth. With say an 1/8th inch of movement at the gears, it would probably translate into a wide arc at the tip of the rotor.

The photo compares a worn gear on the top, with a shot gear on the bottom. Pulling the distributor would tell you quickly if you have a similar problem.

Just for fun I pulled the cap off of the CA, the rotor has nothing like the play the WD45 has. I pulled out the plate that holds the points, and the shaft moves quite a bit before engaging the weights. Going to replace the springs, and that goofy looking rotor then see what happens.

Do any other make of tractor use the same distributer? When I do a search on steiners website, an IH distributer gear comes up.

Mike in Ohio · Jun 22, 2018

(quoted from post at 11:00:36 06/18/18) When I disassembled my G149 (conceptually identical distributor and governor relationship), I removed the distributor and the drive gears were shot. It had a lot of slop in it, but had been running fine, nothing like you describe. I ended up replacing the distributor and the governor. I can imagine that between both gears being so worn, you might get that much play, so maybe that's what is causing the slop, but not necessarily causing the running issue. After seeing how absurd the wear was on these, I guessed that over the years, timing it compensated for the wear, but unless it got so bad that it jumped teeth, it would be fine since it was under load all the time. The governor gear was worn also. The distributor gear was nearly a knife edge as you can see, and it's supposed to be about 1/16th of an inch of gear tooth. With say an 1/8th inch of movement at the gears, it would probably translate into a wide arc at the tip of the rotor.

The photo compares a worn gear on the top, with a shot gear on the bottom. Pulling the distributor would tell you quickly if you have a similar problem.

Thanks guys, haven't been able to get out to the shop this week, hopefully will this weekend?

rotor play

Mike in Ohio

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old

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