VRO conversion 150 hp

[pastorbud]

I researched some more and it looks like the component I can't seem to put back together is the vacuum assembly. It looks like it was held in with a retaining clip on the inside of the VRO assembly. My guess is that clip broke, or came off when the previous owner pulled it out. I wrapped it with electricians tape to increase the diameter a little and pushed it in for now.

 

[pastorbud]

I researched some more and it looks like the component I can't seem to put back together is the vacuum assembly. It looks like it was held in with a retaining clip on the inside of the VRO assembly. My guess is that clip broke, or came off when the previous owner pulled it out. I wrapped it with electricians tape to increase the diameter a little and pushed it in for now.

Hey, what does the vacuum assembly do, anyway?

 

[cfauvel]

Sorry PastorBud, but I've never heard having the electronic portion of the OMS remaining connected would shutdown the motor, but maybe with the system check it would do that...but again never ever heard of that.,.

what WOULD happen with the oil inlet disconnected and oil electronics connected is that the horn for NO-Oil will sound...

the vacuum switch is the fuel obstruction switch which will sound the horn and will go away as you pull back the throttle. If there is a fuel obstruction before the fuel pump the vacuum will rise and at around 5 inhg will close the circuit and sound the alarm.

 

[pastorbud]

Musta just been a coincidence. I did get that alarm before, and no spark. When I disconnected the 3 wire connector, the alarm went away, and I got spark. But I also messed with the ignition switch, and re-connected the kill wire at the ignition switch, which the previous owner or his mechanic had disconnected. My guess is, he was trying to test for a no-spark situation as well.

I have CDI's troubleshooting guide downloaded.

 

[racerone]

Need to look into those compression numbers before spending too much money and effort on this motor.

 

[pastorbud]

Need to look into those compression numbers before spending too much money and effort on this motor.

Yep. I'm pretty much in denial here! Good news is, as I was testing for spark, I disconnected "the port 4 pin connector", as recommended on p. 67 of the CDI Electronics guide, and the silly thing tried to start! By then I had enough garden hose thawed out to put the "muffs" on it, and with the 4 pin connector off, it fired up and ran. Ran rough and smoky, but it ran. I reconnected the 4 pin connector and it stopped. The book says that indicates a problem with the key switch. Even if I replace the motor, I'll still need a new key switch, so I'll at least go that far.​

I also got no water out of the "pisser", so either it's frozen shut, or the pumps not working. Or I broke an impeller running it so cold. I shut it off pretty quickly, since I had no coolant.

 

[pastorbud]

Need to look into those compression numbers before spending too much money and effort on this motor.

So, I finally got enough time and warm weather to re-run the compression test. I didn't do it right the last time. I had not warmed up the engine (no flow from the "pisser"), and I did not have the throttle wide open.

With the lower unit off, I connected a hose directly to the water input pipe-- lotsa flow then.

I ran the engine for 10 minutes or so, using a timing light to check for spark. Good spark on all 6 cylinders.

Compression came in at 90 PSI or a few pounds higher for every cylinder.... but one weird thing.

The engine would often "kick over" like it was trying to start. At about 90 PSI, it would kick over, disengaging the starter. No matter how many times I tried, on four of the six cylinders, it would do that. On the other two, it ran up to 90-92 PSI and stayed there.

I also noticed one spark plug was blacker and drier than the other five.

 

[oldboat1]

need to have the plugs out of all cylinders for compression testing. Crank on one until the needle stops moving, record the number and move on to the next cylinder. Throttle position makes no difference with two cycles.

Change the impeller.

 

[pastorbud]

Problem is, I can't keep cranking until the needle stops. On four of the six cylinders, it cranks until the gauge goes to just over 90, then the motor "kicks over" as if it were trying to start. The starter Bendix disengages and of course the motor stops cranking. I may have to video this to explain. I've never seen it happen before.

 

[pastorbud]

The plugs were all out when testing.

 

[racerone]

Pull the starter apart and inspect the bearings / bushings.----Take ohm reading from shaft to commutator.

 

[pastorbud]

Roger that.

 

[pastorbud]

I got the starter off. Having the battery tested while I'm at it. It did seem to turn over slow, but my charger said the batter was fully charged.

I hope to take it apart tomorrow.

I checked the resistance on the starter (not yet taken apart) from the negative to positive posts and got 0.8-0.9 ohms, BTW.

I also put up a separate post on a "smushed" rubber tube (crossover tube?) that I found behind the starter.

 

[racerone]

Report the ohm reading from shaft to commutator when it is apart.----Should read infinity on a digital meter.

 

[pastorbud]

Can you point me toward a diagram so I know for sure what the commutator is? And where to measure on the commutator?

 

[Chris1956]

Starters are just basic DC electric motors. They have an armature that spins, a copper-plate commutator that the brushes contact to "commutate" the electricity into the motor, armature coils and a magnet or electromagnet field (the stationary part of the starter),

The commutator cannot be shorted to the armature, if the motor is to run. So each copper contact of the commutator will have continuity to each other contact (depending on the wiring), but not to any part of the armature

A picture would be better....

 

[pastorbud]

Can you point it out on here?

 

[pastorbud]

I hope this link from the old site works. I can't seem to find a parts diagram on the new site.

 

[Chris1956]

sure, Item #3 in the diagram is the armature. The very bottom part of the armature has the commutator. That looks to be the same style as a Mercury outboard starter, so yours could be different. That one will have wedge-shaped copper contacts and matching brushes.

You might look at the diagrams at the crowleymarine web site under parts.

 

[pastorbud]

Thanks