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430b v6 water intake warning

mcw

mcw

Contributing Member
I have the v6 430b and recently while out on the boat i lost all water to the engine, very very luckly i noticed quickly and switched the engine, we got a tow in from a local boater, and after an hour returned back on the water and the boat ran perfect all afternoon.

Is there anyway were i can add some kind of warning device to alert me to the no water problem if it happens again, or can i add in my top hoses a T conection and from this supply a very small diameter tube to the stern to give me a very small flow of water showing that water is present in the system like the outboards engines have.

any idea would be great.

thanks

mark w
 
If you'll perfrom the routine maintenance, you'll have no issues and will not require any type of warning device, IMO.
You have an engine temp gauge that should serve your needs.

You have a "water neck" fitting (aka hose connection) that must be routinely replaced.
These corrode, and when they do, we loose all suction. Only takes one tiny breach of suction and the engine mounted sea water pump cannot pull sea water in.
This is often a point of failure quickly resulting in over-heating.

It's shown as SEQ #25 here.

10075.jpg

This is a great time to replace the drive shaft bellows, since the transmission is usually removed for this replacement.
No need to remove the entire drive.
If a shop tells you that the entire drive must be removed.... find another shop. :mad:

These can be replaced without removing the transmission, but my thoughts are, you may as well kill several birds here by replacing the drive bellows at the same time.

.
 
hi RicardoMarin

Thanks for reply, i replaced the intake neck in question last year, i found it brocken when i removed the drive, as the engine had to be lifted.

I think the problem may of been caused by cavitation in the water pump, over the last few years i have noticed that the face plate on water pump impeller has got very large gawges on inner side, i brassed the face and sanded it flat, and now back in boat with another new impeller, have not test it yet thou hopefully the weekend if weather inproves. i have but clear hoses on the engine, but this is only viewable if engine cover is removed.

I thought may be a small house joined into the main system is a good way to just look other the edge of the boat and see the water flowing, a quick and easy check.

Hope your keeping well Recardo thanks for reponse.


mark
 
You'll want to remove the clear hoses. They may not prevent suction collapse! Not good!

The plate that you repaired is only one of two thrust surfaces in your impeller pump.
If the other thrust surface is gouged, the impeller may not seal correctly.
It may be time for a pump replacement.

Also... the cam depressing/folding of the blades is critical as well. You'll have limited suction/pressure if the cam is bad.
Cams can also take on a wear pattern.

Long shot.......... but if someone has replaced the crankshaft pump with a large volume Jabsco, there is an issue to watch out for.

There are two sizes in both Jabsco and Johnson pumps....... large and small!
The Jabsco and Johnson small pumps can both use the 1027 impeller.

All four pumps use the same "spline drive" shaft configuration...., and all four impellers use the same blade count and diameter. If you were to lay each of these impellers flat on a table, and were to look straight down on them, they would all appear to be the same.

However, of the two large pumps, there is a .090" difference in width (not diameter) of the two impellers, and this gets parts counter people and customers into trouble if they are not aware of this, and/or if they do not follow model #'s and p/n's closely.



Here are the impeller blade width differences between the two large pumps;
  • Johnson large pump impeller thickness/width = 1.900"
  • Jabsco large pump impeller thickness/width = 1.990"
The risk is in using the more narrow Johnson impeller in the deeper Jabsco pump body.
All else appears to be same....., it slips right into the pump body, and we think all is good!
So it's an easy mistake to be made.

The only other potential issue may be where the pivot tube makes it's seal at the lower drive unit.

Other than these potential maintenance issues, these systems rarely give us any trouble.

.
 
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