BF75 or BF100 Points Condenser Help???

From previous threads I have posted you may know I have picked up a couple outboards that are breaker points motors. One is a BF75Z (7.5hp 1979) and the other a BF100 (1978). Cant get either one started. Tested coils, kill switches, new plugs, etc. Only thing I can't test is the condensers. They are no longer available on everyones parts list. I did find a company overseas that thier website says the have them but they are physically checking to see if they have a couple or not. Even then with shipping and the cost of the part I am looking at $75+ for 2 of them.

Honda part number= 30020-935-004

Has anyone found a replacment condenser for this part that is cheaper and more available? If so what part number and or where to get it?



Thanks,
Jeff

I have always thought than "ONE DAY" I would get around to sourcing a 0.24uf (or, 24 micro farad) replacement for these at the local auto parts store. Because....THEY ARE THERE. Many of the stores carry these "wax paper and foil" capacitors because there are still plenty of old ignition point fired cars from the 50's and 60's still running around. But, ALAS, it is just not high on the list right now.

But if you can make friends with a guy at NAPA or one of those parts houses, they may be willing to try to find one for you. They are likely to stock a handful and just ask if you can take a peek in the box.

The problem is that I seem to remember that most of the condensers on the cars I used to work on were in the .030uf (30 micro farad) or above range. But that wouldn't keep me from trying one on the outboard to see if it fires. I'm not sure you should run one like that for an extended period however since it COULD be detrimental to the ignition coil's health. But, I may be wrong about that too.

Another way to skin the catfish is to go to a GOOD electrical supply store....the place where the Oscilloscope and HARD MATH guys hang out and find a 0.24uf (24 micro farad) capacitor that will fit in the spot. Sometimes they are friendly and helpful at those places and sometimes not so much....it's the luck of the draw. If they like you, they may be able to suggest something that will work.

They may also help you test the ones you have. A decent capacitor tester costs around $50 but I have one built in to each of my two Fluke 87 meters. Many digital meters these days have capacitor testing built in. You can "sort of" test one with your ohm meter by doing this:

Discharge the cap by touching the pig tail end to the metal housing.
Set your meter to HIGH ohms and touch one lead to the pigtail end and the other lead to the housing. You should see the resistance start out VERY high and then begin to drop. If that doesn't happen, discharge the cap again and then do the same thing except with the leads reversed. If you see the resistance start out high and then start to fall quickly, it is LIKELY that the condenser is ok. If nothing happens, then the condenser is "open". If the resistance is IMMEDIATELY very LOW...the condenser is "shorted" or grounded.

So, you are still not SEEING any spark? In a darkened room or under a hood?
Are you using NEW plugs?
I ask because the measurements that you took before were indicative of good components.
But, you're right, it could be the condensers.

Have you done a compression check though? These engines will not fire if the compression is too low. No engine will. Or, if the spark happens at the wrong time.

I'm very interested in your efforts to get 'em going and I hope you can figure out what's going on.
Good luck and keep us posted.

A couple of other thoughts about this:

I mentioned NAPA because they DO have a spark plug reference for HONDA OUTBOARDS and a filter cross reference guide. Those stores usually carry more parts for more types of machinery than most other parts stores do. So, that is the place I would start my search.

Also, if you can find a .024uf capacitor (condenser) and it doesn't exactly fit, just remember...it only needs to be hooked to the GROUND side of the points with the wire...it needs to be GROUNDED itself to the points "case" or plate and it needs to be secured from moving around. You should be able to "make it fit" if you can accomplish these three things. Nobody is going to notice couple of extra little holes in that points plate for a hold down strap and a couple of tiny screws.

And, while we are on the subject of the grounding of the points...make sure that the INSULATOR for the feed wire from the flywheel coil to points and from points to the ignition coil isn't grounded. This goes for the wiring too. If ANY part of that ignition wiring happens to be finding ground....it will kill the spark.
Because, that's what the kill switch does....it grounds the coil.

Good luck.

I am still waiting for the compression gauge I ordered to come in. I borrowed a gauge from my father but it didn't have the 12mm adapter. I did get the motor with the CDI going. It is a long shaft so I am swapping over the parts from my short shaft points motor to the CDI. Waiting on an impeller to arrive and will get that motor ready first.

On the points motor I have a couple otherquestions for you:

Timing- To make sure I set it correctly did I do this right? I set the fly wheel to “T” mark and then aligned the punch mark on the engine block to the punch mark on thep ulley cam. Once those were aligned I placed the timing belt onto the cam making sure the belt fit in the notches to keep the marks aligned. Correct?From this position I would also be able to adjust the valve clearance as well correct?



I then moved the fly wheel/cam with the timing belt attached and a couple revolutions until I had the “F” lined up with the aligning mark the fly wheel is mounted to. From there adjusted the points using a .014 feeler gauge.

As far as grounds go I think I may have found an issue with the 10hp points motor. Both motors have had some wires altered. Mostly just new crimped on ends. As far asI can tell the only wire that should be grounded to motor is the kill switch.On the 10hp the black wire from the primary coil under the fly wheel is grounded to the screw that the kill switch is grounded to (motor frame/case). That wires hould be attached to the ignition coil correct? Putting it on the kill switch ground screw is basically grounding the primary coil to the motor frame correct?

It sounds as if you got the VALVE timing correct...IE: T on flywheel aligned with scribe mark on post and punch mark on cam pulley aligned with scribe mark on post...install the belt keeping these three things aligned.

And then, yes you can position these marks for checking/adjusting ONE CYLINDER'S valves, while closed, on TDC. Rotate the engine 360* and check/adjust the OTHER cylinder's valves.

The ignition timing may be off a bit according to what you said that you did. The points should not be gapped to 0.014" at the F mark. The F mark is used to determine when the points START to open. Use your ohmmeter to set the points like this:

Unplug the wire from the primary coil (under flywheel) from the ignition coil terminal "pigtail" and connect one lead of your ohmmeter to that pigtail or to the wire terminal of the coil.

Connect the other meter lead to a reliable engine ground. When the points are closed, there should be continuity. As the engine is rotated so that the F on the flywheel is aligning with the scribe on the engine post, the points should JUST begin to open and your meter will show infinite resistance.

AGAIN, with the F mark on the flywheel aligned with the scribe mark on the engine case post, adjust the points so that they JUST begin to open. Setting the points in this manner is a bit more precise and will give you maximum "dwell" for the hottest spark possible. This should also result in the points reaching the specified MAXIMUM gap of 0.014" when fully open

The primary coil for the points should have two connectors. One goes to the kill switch and the other goes to the ignition coil wire terminal. You are correct that this coil should not be independently grounded but is ONLY grounded when the kill switch is depressed.

I hope I got all that right.

On the 10 hp I got it to pop

The points were not set right. I adjusted them using the multi meter ad you described. I also moved the black wire that was grounded from the coil under the fly wheel to the ignition coil post.
Spark tested it and got spark. Squirting of starting fluid and it pop twice. Saturday will hook it to my tank and see what happens.
Thanks again for getting me this far and I will keep posting updates and help questions.

YEAH BUDDY!

Take it easy on the starting fluid though. Every shot of that stuff takes a little piece of the engine with it! I stopped using it for testing years ago since it DOES damage and DOESN'T give accurate results.

An engine will "cough", "pop", "sputter"...whatever...on starting fluid when it might not on gasoline. This could lead you to believe that the engine should run even if something is amiss.

It's more of a pain to use (a helper makes it much easier) but PROPANE gas is a superior "artificial enrichment" fuel that will have a PROPERLY timed and sparked engine running smoothly with no danger of hurting the pistons, rings and valves. Use ONLY outdoors though!

Starting fluid (ether) is HIGHLY volatile and actually EXPLODES in the cylinder causing damage to metals. I recommend ONLY using it in an emergency.

But...lots of guys still do.

Yep, use starter fluid very sparingly if you do use it, strips of any lubrication it comes in contact with too. I have a squirter bottle with fuel in it for this purpose. A squirt of that into the carby and you should get a few pops if ignition is working properly and won't harm the engine.

With the condenser, I would just see what you can find from an automotive shop or motorbike parts store and give it a test. You shouldn't do any harm if it's not exactly matched to the original part other than possibly getting little or no spark if it's too high a capacitance or maybe pitting/burning your points if it's too low. Even without a condenser you should get spark and a running engine but your points won't last long. If you can find what the capacitance of the original is supposed to be then you may be able to get close or match it which would be better than Trial and error. I bought a capacitance meter from ebay a few years ago for about $30 delivered from China (although I've never thought to test an ignition condenser with it) which should make testing and matching easy as pie.

It seems that jgmo has the answer to the capacitance being 0.24uF. You could try calling Bosch automotive or Lucas and asking them if they have anything that is close and where you might purchase it. Should only be about $10 I would have thought. Not sure about sourcing one from an electronics store though as I think ignition capacitors have a high voltage rating around 400-800 volts and I don't know if this is common for electronic components that aren't purpose designed for ignition systems.

I picked up a new multimeter. Just a harbor freight one but it has uf or capacitor features. On sale right now for $24.99

Pulled the capacitor on the 7.5hp and got a .23 uf reading. Not knowing capacitors are they on the dot or +/- ok?

Yes, they are typically rated with a +/- of a percentage (%) value. I don't know offhand what that % is for these condensors.

The spec for these being .24uf I don't think I would worry about the .23uf reading you are getting with the HF meter at all. It tells me it's CLOSE ENOUGH, and that it HAS capacitance and ISN"T shorted. Which, at least in my mind, is ALL you need. I'd call it GOOD.

Definitely good. For consumer grade parts most electronic components are +/- 10% so you are good.

On the 7.5 HP I got .22 uf on the condenser.

Well, they're old....and that Harbor Freight meter may not be entirely accurate. There is also a + or - factor on meters and the less expensive they are the bigger that number usually is. And, since they come from China...they don't even have to tell the truth about how they are rated!

I would only suspect that the condenser would need replacing if the points burned and pitted badly in a short amount of time. Although, I have seen them cause problems with ignition before and finding some fresh ones to compare to would ALWAYS be a good idea.

Otherwise, I'm still calling it good.

jduck1 said:

From previous threads I have posted you may know I have picked up a couple outboards that are breaker points motors. One is a BF75Z (7.5hp 1979) and the other a BF100 (1978). Cant get either one started. Tested coils, kill switches, new plugs, etc. Only thing I can't test is the condensers. They are no longer available on everyones parts list. I did find a company overseas that thier website says the have them but they are physically checking to see if they have a couple or not. Even then with shipping and the cost of the part I am looking at $75+ for 2 of them.

Honda part number= 30020-935-004

Has anyone found a replacment condenser for this part that is cheaper and more available? If so what part number and or where to get it?

View attachment 10775

Thanks,
Jeff

Click to expand...

The condensers for the CB750, CB550 will fit the little outboards. The points for the CB350, CB360,CB400 and CB450 can be used to replace the plastic arm with one point, reusing the original base as long as the second point in it is not too worn. Here is a list of good candidates with part numbers.

My 7.5 did not have spark until I replaced the condenser with a 25 muf i found on Aliexpress. I also need a top cowling that I could trade for a cowling from the K1 first gen BF75, which is wider and shorter for my outboard. I also have the powerhead, mid section and other parts available.

Here is the list, does not seem to upload though