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Honda b75 starting problem

J

Johansa

New member
Hi guys,

I do got a Honda b75 from early 70ies without CDI ignition that gives me a serious headache.
Cant get the engifte to fire, from My findings it must be something with the ignition.
I cant see any spark on the plugs (from reading on this forum i know that the spark can be weak on this modell and hard to see).

I've disconnected the stopbutton for test proposes without any luck.

Currently setup:

Spark plugs = new NGK D5HS
contact breaker gap = 0.3 - 0.4mm
Capacitator = unknown functionality
primary coil = looks brand new
secondary cool = part-no AC6V-20

Anyone that have a idea how to proceed?

Best Regards from Sweden,
Johan
 
Thanks!

yesterday i removed the capacitator and points. Switched to another pair, got a more intense blue spark. But it wont crank up, i can see that the sparks has fuel on them. Will try another set of sparkplugs if that Will do the trick.

BR.
 
Is this outboard one that you have had for some time and know that it did run ok? Or, did you just get it recently and don't have much background knowledge about how it worked?

If the outboard is "new to you", then you will probably need verify a few things about it's overall condition. If you have spark (you indicate that you do now) and you have fuel ( you say the plugs are wet) if you still can't get it to fire then you will need to make sure that the timing is correct. There is valve timing and then there is ignition timing. Both should be checked and corrected if need be. After that, there is compression. Without good compression, the engine is not likely to start and run.

So, if you don't get it running by drying out the plugs (or replacing them), don't hesitate to ask back here for how to check these other things. If you have the shop manual, it makes doing so a lot easier but if you don't, we can walk you through it.

Here's a little trick to try after you've dried off the spark plugs:
Before putting the plugs back in the cylinders, tilt the engine up as far as you can and try to get the spark plug holes pointing up to the sky. Make a little funnel out of paper and then pour about a teaspoonful of engine oil into each cylinder. Then SLOWLY pull the recoil starter to carefully and SLOWLY turn the engine over. What you want to happen is that the oil you poured into the cylinders gets spread out across the top of the pistons. Then, let the outboard sit like this for about 30 minutes. After a while, reinsert your plugs, drop the outboard into the normal position and attempt to start it again.

What happens sometimes when an outboard sits for a long time and then gets cranked alot without firing, gasoline "washes" down the sides of the cylinder walls. This can drastically lower the compression and, on a well worn engine, might lower it enough so that the fuel won't vaporize and ignite...Thus...wet plugs. Pouring oil in the cylinders is a way of helping the piston rings to seal against the cylinder walls and increase compression. It might increase it enough to make a difference.

Good luck.
 
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