Power drops/cuts after engine warms up 10 minutes 1994

Odd, I agree.
I keep thinking- sitting in a shed for 7 years, symptoms after driving first 2 hours..

I am going to pull the tank and fairings and go over every detail making sure all hoses, cables, wires etc. are intact and sitting where they should be. I will test pulse then too.

If nothing obvious-

Test compression and visual inspection of carbs.

I have expected a few things to be off after sitting this length of time. Now that I think of it, I remember there being "slack" in the throttle cable at the valve pully as well....

 

Update-

Pulled all and checked everything.

Adjusted slack in throttle and reset the black knob.

Tested Pulse Generator and one failed (blue connector)- the other was at 288ohms

Dizzy wins, sort of:

Bike runs quite nice now without any problems with heat etc. Drove for about an hour in all conditions and it seems to be ok.

Questions:
Am I running with just one PG?
Is the second just a backup?
Will it run better with both working (I am assuming yes) or do I just need to replace it before the other one fails?

Thanks

 

PG's are kinda like the solid state equivalent of contact breakers...or points. Each is 'keyed' to the crankshaft in a certain position to signal the ignition the precise point to spark. Since each cylinder bank...front and rear...have different timing requirements, two PG's are used for two completely distinct signals. So the answer is you need both functioning. If one fails, you will lose spark on that cylinder bank...but not the other, so your bike would run on only two cylinders.

A PG can just up and fail...but sometimes they can be intermittent. When that happens they tend to fail when they get hot. As they cool...they can start to work again...most typically takes 5 or 10 minutes. The one thing I've found is resistance is a good indication of how a PG is working at that particular moment in time. In other words, If one is intermittent (fails when hot), it will test totally good when you test it cold. But as soon as it fails, it tests bad...usually they open circuit.

I don't know why you have one testing bad but your bike runs fine. Unless you've already replaced it, or you tested it when your bike failed.

Anyway, the significance of this to the fuel system is...Honda doesn't just run straight power to fuel pump. They wire a separate relay in (fuel cut relay). This relay gets a signal from the ignition (usually one of the coils) and THAT allows power to the pump. In other words, until your engine is turning over and producing spark on that coil, you have no power to the pump. That's also why the pump doesn't just run when you key the ignition. So if say...the PG, ignition box or coil quit working on that particular bank...your pump will quit pumping....whew...hope that makes sense.

 

Awesome.
Feel like I just went back to school. I understand the system now and that means alot to troubleshooting instead of just following this and that.

I am going to fit a new PG just because and see if the overall performance improves. It is not what I would call perfect right now and I dont want another long road failure. If all goes well I want to take this bike on regular 4 hours rides.

Thanks guys and big thank for the explaination Dizz..

 

I may be to late for this post... but I had exactly the same problems... turned out to be the regulator..
fitted a new regulator and the bike was as good as new..

 

That thought has crossed my mind.


The PG is on the way so I will fit that first.

BTW- the PG tests as bad on the blue wires consistantly. After pulling to test the last time, the bike now barely starts and floods very quickly. You can tell that it has a few cylinders that are not firing by the sound, not to mention the exhaust filling with fuel! I think the PG's seem to fail slowly before really letting you have it.

Should be done with the repair by the end of the week and will update then.

 

Sounds like you are on 'track'. An R/R failure is charging system. Most Honda's you can totally unplug the R/R and the bike will run fine until the battery VDC drops enough to not be able to 'run' the ignition system.

While it may seem similar to an ignition failure, the symptoms are really quite different. The main 'clue' is the condition of the battery when the bike quits running...that is, it's extremely discharged.

 

I fitted the new Pulse Generator last night.

Tip- be very careful with the small spacer BEHIND the starter gear. I put it in front, assembled, looked at a diagram, took back apart and put it in the right place.....wow...

Ok- here is the thing. My oil was clearly mixed with gas.
Was this likely caused by running on two cylinders while trying to diagnose the PG problem? It was severly flooded last start-up.

PG tests as fine now and I thought it didnt work..bike sputtered to a stop.. I pushed it back into the garage, started taking off fairings then, midway decided to look in the tank. Of course it was empty!

So- should I fill the tank, change the oil/filter and start it up or should I pull the tank and check the carbs just to be sure nothing is stuck (full carb work just done in the past few months)

Thanks in advance Guys.

 

I would change the oil ASAP to clear the gas/oil mix (use a cheap oil) and then run for 200 miles give or take and put in your usual MC oil

 

Cheap oil such as? Type /brand?
I have 2 extra oil filters so that sounds great.

I too thought about this and think it might not be the worse thing to have cleaned the engine out like this.

 

Whatttttt???

I couldnt bait you guys into an oil discussion/war?

 

just a decent motorcycle oil from your dealer. since you arent going to run it long, whatever is cheap. make sure it's MC oil and not Auto

 

Ok -now I am confused.
This may be worthy of another post starting but I will just do it here for now.

New gas-

Ran bike for five minutes then it started acting "flooded".

Came home and found fuel leaking (like an overflow) somewhere between the two rear cylinder banks.

Pulled apart and checked for spark...fine. Checked all connections with a meter at the brain..fine. start switch, neutral switch, side stand...all good.

If it is getting too much fuel and causing an overflow type leak at the rear bank could that be debris in the carb or a carb fitting leak?

Getting a little frustrated at this point. The weather is good and I wanna ride.

 

carb float stuck?

 

See pic, install clear lines on the float bowl drains, run them up about 4 inches, open the drains and run it when it screews up see which one is higher than the rest. When a float sticks the level goes up and floods.

 

has your lash been checked. I spent days screwing with my carbs till i bought a o2 sensor and meter found my carbs to be perfect. so i pulled it apart and found my lash to be very tight.