Honda B75 questions...

[tcooke]

First off, I was talking to my local Hoda dealer and they can't any info on my motor?!? I have a B75 - 4011894 4 stroke motor, they can't seem to find anything in thier system that matches it.

So here are my questions....

1. What year is this motor?
2. Would the fact that it came from the US (I'm in Canada) be the reason for them not being able to find it?

Now onto the mechanical issues for anyone amiliar with these motors....

1. I am not getting a big enough spark to ignite, would this require new points and if so where are the points located? (Pulled the plugs and could only see a small, barely visible spark)

2. Is the ignition unit a one piece houses all? As this is the only ignition part that I could find

I really appreciate the help, thank god for online forums

 

[Nick on the Bad Habit]

Re: Honda B75 questions...

Take a close look at your spark plug wires. Mine had a date stamp on the wire jacket. Make sure that the spark plug gap is not to wide. If you suspect a weak spark try closing the gap on your plugs, sometime the engine will start and run that way. The spark on mine looks weak also but starts and runs fine.
Good luck, Nick

 

[hondon]

Re: Honda B75 questions...

OK, let's get started.These engines are very cold sparked on pull over even if you are CDI ignition. I take them to the back of the shop and turn the lights off.If you have points they will be under the cam pulleys rubber cover.Remove the spark plugs and the cover and turn the engine slowly by hand and trough that slot in the pulley you will either see points at some point or not.CDI will also have a black box mounted above the intake mani,a fuel pump that is not shrouded,a little later a neutral switch,you get the idea.I will try to remember to run those #s to tell you what you have.What color is this unit?

 

[tcooke]

Re: Honda B75 questions...

The motor is white with blue stripes.

As for the issues I am having with getting this motor running, it is not cdi and does have points, which have been cleaned up and I have tested the spark on each cylinder. Both plugs get at least 3/8" of arc.

Secondly I have double and triple checked the cam alignment. The dot lines up with the dot on the head while the "T" line lines up with the mark on the flywheel case.

Thirdly, the carburator has been taken apart and completely cleaned and tested that all passageways and jets are working.

The motor will still not ignite no matter how long I pull away at it and what the choke and throttle settings are. Not even one little blurp.

So now I am left pondering what the cause of the non-start is. Would it possibly be bad compression??

Thoughts....... PLEASE!!!

 

[hondon]

Re: Honda B75 questions...

Certainly.Any project that you start on any engine requires a compression,ignition output,and fuel sample test.If you fail any of these you are are least pointed in the right direction.

 

[tcooke]

Re: Honda B75 questions...

Well I finally got a compression tester and it read 0psi on both cylinders. I checked to make sure the tester was working and it is. So I removed the head and inspected it and the cylinders, found no cracks and the gasket was good as well.

Any more thoughts? Valve seats? Valve adjustment clearance? WHere should I go from here?

 

[tcooke]

Re: Honda B75 questions...

Well upon further inspection after dismantling the head I found that both intake valves have been bent causing the compression problems.

Thanks to all for your input.