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1985 B or BF100 Not starting.

I

Issac08

New member
I'll just start this off by saying I'm not sure what model number this is except it says Honda 100 on the cowl. The identification plate is not on the starboard side of the frame it's removed but I'm guessing 80s model motor. Took the carb off and cleaned it. Removed the old gas and replaced it. All my lines are good. The exciter coil shows 360 ohms but that's within the 330 plus or minus 10% so I'm assuming that's good. I can't take the spark plug caps off to check the ignition coil and I'm not getting spark as well. Not sure where to go from there.
 
Good news! Faulty kill switch. Runs like a champ at idle. Doesn't like WOT. Just kind of putts around. Carburetor issue still?
 
Hi, yes...very likely carb problem but I would also verify cam timing is correct. Try squeezing primer bulb and or choke it some when throttling up. If that improves the way it runs then it's definitely a fuel delivery issue.
Does this engine have breaker point ignition or is it CDI? If it has points, make sure they are in good shape and are properly adjusted. A faulty ignition condenser could also make the engine "fall flat" on acceleration too.
Good luck.
 
Squeezing the bulb produces no noticeable differences. When we have the motor idling it will idle great with throttle. It throttles up completely when we have the motor in the garbage can but it does take a while to throttle up. Only when it's in the water it doesn't like to accelerate. Like it doesn't like the load given to it. The boat is a small 14' fiberglass hull. A creek boat. So it doesn't seem likely that that will be the problem. When at WOT on the water it'll have split second jumps in RPMs but will never stay constant.
 
how does it run with cover off? I had the seal between the top half and the lower unit fail causing exhaust to pressurize top half of engine
 
The "try with the cover off" is a good suggestion since these are known for developing exhaust leaks. However, this sounds more like it COULD be that you have a dead or "low contribution" cylinder. These engines WILL run on one cylinder and WILL be smooth enough to fool you into thinking they are both firing. I would try a new set of plugs (if you haven't already) and check that both cylinders are getting spark. Checking these for spark is done easily if you have an induction timing light and a spare 12 volt battery to power it. If you're not set up for that, you can do it visually by removing and grounding the plug in the "old fashioned" way but the spark, even when its good, on these is very faint and hard to see in the daylight. Done in a darkened garage or with a blanket over your head and the outboard is a good way to go. Nighttime testing works too.

If you verify spark is good then it might be time to perform a compression test. You should verify that the cam is in time and that the timing belt is snug and hasn't "jumped" a tooth or two as this could cause the engine to be "weak" but still run. If compression is low on either or both cylinders you will want to check the valve adjustment. If the valves are properly adjusted but you still have low compression, then you likely have cylinder ring issues. It might not be a catastrophe though as it could be just some carbon buildup has caused the rings to "stick". Since the engine runs, you could try performing some "decarb" treatments to free them up before you think about going into the engine.

And of course it could just still be a fuel delivery problem. I wanted you to try pumping the bulb to rule out a fuel pump problem and you have. So, You didn't say how it ran if you tried running it choked. If that improves things then I would definitely suspect carb. But if it doesn't run better with the choke out then I would rule it out.

Good luck.
 
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