old mallory distributor question

[tworevs]

I have a 73 crestliner with a 350 Chevy engine and omc stringer stern drive.

When setting the points, I notice that I can turn the rotor by hand to any position I want. It doesn't seem to take much effort to do so. Just doesn't seem right and I am worried that it might move while running thus changing the timing. It hasn't been a problem yet. It is a mallory YL 520 EV distributor.
Is this normal for that distributor?

Thanks,
Todd.

 

[Don S]

Re: old mallory distributor question

The rotor should be replaced during a tuenup, and it shouldn't turn on the distributor shaft. If it is, replace the rotor. If the shaft is turning too, you have a much bigger problem.

 

[tworevs]

Re: old mallory distributor question

I was afraid someone was going to say that.

It is deffinately the shaft turning. It is not the gear end slipping on the camshaft, so it must be the points cam slipping on the dist. shaft.

Thanks for the quick reply,
Todd.

 

[EddiePetty]

Re: old mallory distributor question

....look for broken, missing and/or weak mechanical advance springs under the breaker plate.

 

[Aloysius]

Re: old mallory distributor question

The gear drives the oil pump also. The advance is locked into slots, so even with broken springs it would turn about 10 degrees. there's a Jesus clip under the rotor that holds the cam assembly..if it's broken, the cam lobe assembly may have lifted out of the advance stops. Rest assured it won't run now until everything is oriented properly.

 

[tworevs]

Re: old mallory distributor question

I will do that when I get the distributor out tomorrow.
I can turn the points cam all the way around, so I don't think it is the advance mechanism. I will keep you guys informed of the situation.
Thanks,
Todd.

 

[captk]

Re: old mallory distributor question

The shaft that holds the rotor shaft and point cam is held down with a clamp to a plate (advance plate), under the point plate,and they slip occasionally. You need to replace that plate. A kit used to be available from mallory, but I haven't done one in years. If it is a flat cap you could get the kit for the high tower cap but need to change wires cap and rotor. but that may be cheaper than those flat caps. OMC part #382897 is a direct replacement but is nla. I have one if you need it send me a pm. Good luck Bill

 

[tworevs]

Re: old mallory distributor question

The shaft that holds the rotor shaft and point cam is held down with a clamp to a plate (advance plate), under the point plate,and they slip occasionally. Good luck Bill

http://www.boats.net/parts/search/O...IBUTOR GROUP 225 & 245 STERN DRIVE/parts.html
I found this parts fiche to use as a guide when disassembling.
Looks like a lot of these parts might still be available.
The clamp you refer to must be #16.
Thanks for your help,
Todd.

 

[tworevs]

Re: old mallory distributor question

I believe I have found and fixed the problem.
It was the cam slipping on the clamp as captk mentioned.
I simply removed the clamp and bent it slightly (arrows) and filed the ends of the clamp for a better bite on the cam. Did this without removing the distributor, only the points plate.
Reassembled, timing, and dwell and all is good.
I cannot move it by hand any more.
Thanks to all for your input,
Todd.
Great forum!!!

 

[sethjon]

Re: old mallory distributor question

I have a 73 crestliner with a 350 Chevy engine and omc stringer stern drive.

When setting the points, I notice that I can turn the rotor by hand to any position I want. It doesn't seem to take much effort to do so. Just doesn't seem right and I am worried that it might move while running thus changing the timing. It hasn't been a problem yet. It is a mallory YL 520 EV distributor.
Is this normal for that distributor?

Thanks,
Todd.

Sounds like the inside of the rotor is broken off. Replace it. I'm surprised the engine even starts.

 

[tworevs]

Re: old mallory distributor question

Sounds like the inside of the rotor is broken off. Replace it. I'm surprised the engine even starts.

All set, thanks