Use of Auto Parts on older Supras

[r007mills]

Is there any real difference between points, condenser, rotor cap inside a Marine Distributor as compared to an Auto Distributor?

[lively]

No


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[CJD]

Good parts will be made with brass contacts for minimal corrosion...but that applies for both boats and cars. My boat came with aluminum contacts from the factory, which are the cheap way out. The older car distributors had windows to set the points...which would be a no-no in a boat, to prevent a flash fire.

[r007mills]

Good point on the window. That brings a question to my mind. Can the points be adjusted using dwell meter with engine running like the older auto distributors with the window or do you just adjust with cap off then test dwell? I'm sure this sounds like a dumb question, but I've owned my 88 Comp since new and never changed the points. Hours are very low (under 300) and I have used boat every year just not a bunch of hours. It has started and ran fine every year but I figure it is due a tuneup after 26 years, LOL.

[michael hunter]

Here are the NAPA part numbers for your boat
Points CS720P
Condenser AL869
Rotor AL125
Dist Cap AL171
SP Wires 188802
Ign Coil
Motorcraft E8TF-12029BA BKC External Resistor
These are for a 351 with a Prestolite dist. You cant adj the dwell with the engine running . You can get a close reading by cranking the engine and then check when running. Remember to increase dwell decrease gap and to decrease dwell increase gap . The dwell for your engine should be 29-33 degrees.

[cadunkle]

The cap is typically vented differently or not at all. Typically a fine mesh screen for venting vs just open or with a cap/hat in automotive. Aside from that no appreciable difference in the other parts.

[r007mills]

Thanks to all for the replies. Michael, those part numbers will come in handy. I store boat near where we ski/board and am never quite sure about replacement parts unless I have the old part in hand to compare. Having the part numbers hopefully will save me a trip.

[Stal1026]

Sierra marine is the supplier for NAPA marine parts. They have a nice online catalog on sierra marines website with the part numbers. Find what you need and go to NAPA with part numbers. Sierra marine has had everything I have need for my 1990

[michael hunter]

If you have an SMP trailer I have all the part numbers for bearings, races and seals they are not the same as the packaged sets.

[r007mills]

Well, tuneup using the Napa Parts:

CS720P Points
AL869 Condenser
AL125 Rotor

Did not go so well. Not sure which part was causing the problem, but I ended up taking all off and putting old parts back in to salvage a little bit of ski time on the water. Dwell would jump around a little at idle but would go way down at increased RPMs (in neutral) and engine would mis really bad on attempt to accelerate beyond a fast crawl. Seemed almost as if points might have been floating open. The points did look much more cheaply constructed than my OEM points. They did look pretty much the same as the pics of the ones sold on SKIDIM site though. See attached Pic for my OEM points:

14848

Could it have been the rotor cap causing the problem rather than the points? The rotor cap looked more like the one that SKIDIM shows for 86 and older rather than the one for 87 and newer.

One other note: there is no door on distributor to adjust dwell with engine running. You just have to gap em, close it up, fire it up and test the dwell and then open it back up and readjust till you get it right.

[michael hunter]

I don't see any grease on the rubbing block on the points. Did you clean the dist cam ?

[r007mills]

That picture was taken before I replaced points with new ones.

[CJD]

I had similar experience when I had a bad condenser, which burns the points in short order. I don't think it's the fact they are auto parts, but rather a defective new part. Do the new points look burned at the contacts?



Well, tuneup using the Napa Parts:

CS720P Points
AL869 Condenser
AL125 Rotor

Did not go so well. Not sure which part was causing the problem, but I ended up taking all off and putting old parts back in to salvage a little bit of ski time on the water. Dwell would jump around a little at idle but would go way down at increased RPMs (in neutral) and engine would mis really bad on attempt to accelerate beyond a fast crawl. Seemed almost as if points might have been floating open. The points did look much more cheaply constructed than my OEM points. They did look pretty much the same as the pics of the ones sold on SKIDIM site though. See attached Pic for my OEM points:

14848

Could it have been the rotor cap causing the problem rather than the points? The rotor cap looked more like the one that SKIDIM shows for 86 and older rather than the one for 87 and newer.

One other note: there is no door on distributor to adjust dwell with engine running. You just have to gap em, close it up, fire it up and test the dwell and then open it back up and readjust till you get it right.

[r007mills]

Not sure I would say they looked burned, but there was some marking on one corner of both sides of the contacts on the points. The new points (and rotor and condenser) were only installed for maybe 3 or 4 minutes of engine time since they did not perform well.

[CJD]

I'd still bet the new condenser was bad out of the box.