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View Full Version : Impeller???---Electrical???


kpbdmd
09-27-2004, 06:12 AM
First time forum user. I have a 2000 Maristar 230 VRS with 330hp - Northstar ignition. Several weeks ago I noticed after The boat had run fine for about 15 min that my engine temp began to increase and the engine bogged down and would not run much faster than no wake/idle speed. The temp was not dangerously high. After letting it sit for 20 minutes, the boat ran fine. This happened two times more the same day, so I took it to the shop and was told to replace the impeller. Possible overheating caused vapor lock. This made since.
Yesterday, after a great day on the lake I was cruising home at about 35 mph and the engine began to bog down just like before. I checked my guages and temp was fine but voltage was low. I limped into a marina and the boat would not restart. The engine would not turn over - dead battery. I replaced the battery and cruised home with no problems.
There is no doubt that I needed an impeller. The battery was original (3.5 years old). I am the original owner. Could low voltage cause the EFI to do this? Could this be an alternator problem? Suggestions?

JimN
09-27-2004, 09:43 AM
You were told to replace the impeller? Unless you told them to find the problem and not fix it, what kind of service is that? Did you take it to a MC dealer? They said possible overheating causing capor lock? Give me a break! :rant: In 2000, the fuel pump was in the tank, pushing the gas to the motor. The chance of vapor lock is almost zero. You normally have around 40 pounds of pressure and even if it goes to 30, it'll still run. If you have run out of gas more than once, it's possible for the pump to be weak, but vapor lock is not going to happen.

Yes, low voltage will make any boat run badly, but this should have been figured out when it was in the shop. If the alternator is working, they should have found about 14-14.6 volts, running without accessories. If your battery is good and being charged, it should be around 13.5 at rest. If the battery has been beed discharged more than a few times, start thinking about getting a new one, especially if it's not being charged properly. When a battery goes to zero volts, you will lose around 1/3 of its current discharging capacity. Starting with 550 CCA, killing it 3 times leaves you with about 30% of your original 550 and that doesn't consider the discharge from repeated starting, inadequate charging by the alternator or the effects on the ability to be recharged from being discharged completely.

If the alternator isn't charging, the most likely reasons are: bad ring terminal on the charging lead (they had a problem with these on your year of boat), bad alternator (this can be verified at a shop that rebuilds alternators and starters), a bad battery and dirty or loose battery cable terminals. If the battery cables were just placed on the terminals and not tightened, you will have symptoms like this. I have seen this quite a few times and while it may be convenient to be able to just lift the cable off when necessary, it's not gonna run right for long.

On the other hand, it could be something simple. Did you, or the shop, check the alternator belt? If it's slipping, it can't drive the alternator and raw water pump. If it has oil on it or is loose, you'll lose voltage and it won't necessarily keep the motor cool. Check the oil cooler for weeds and other obstructions, too.

jimmer2880
09-28-2004, 05:56 AM
The temp was not dangerously high
What was the temp? On cars - 180 isn't bad, but if I remember correctly - 180 on your boat will cause it to go into "limp mode". The actual temp will help us out alot in diagnosing your problems.

BTW - I'm not discounting what Jimn is saying (he is the all-knowing! :worthy: ) just giving another point of view.

JimN
09-28-2004, 09:10 AM
I don't think it was in "limp mode". This is a car term, not for boats- DON'T limp home. Cars have a radiator and usually the only reason a car will overheat is a bad thermostat or radiator cap that is leaky. The fact that it ran fine as soon as the battery was replaced tells me that it's probably a voltage issue.

kpbdmd
09-28-2004, 10:10 AM
Thanks for the response... the "high temp" I was referring to was just less than 200 degrees. It normally runs around 160. The most recent "limp" event was not associated with increased temp. It was a lower than normal voltage that was noted this last time. Again, the boat ran fine on the 30 minute ride home after replacing the battery.(My impeller service was not from a MC dealer.)

jimmer2880
09-28-2004, 11:32 AM
I don't think it was in "limp mode". This is a car term, not for boats- DON'T limp home. Cars have a radiator and usually the only reason a car will overheat is a bad thermostat or radiator cap that is leaky. The fact that it ran fine as soon as the battery was replaced tells me that it's probably a voltage issue.
excuse me... "Reduced rpm mode"... how's that? :rant:

When the battery was replace & the boat was fine for the ride home, I attributed that to the engine cooling down while the battery was being replaced.

Like I said - I'm not saying you were/are wrong - just giving another thing to look at. AND - with the temp being just under 200deg, I still say that's a possibility.8p

:D

jimmer2880
09-28-2004, 11:33 AM
Thanks for the response... the "high temp" I was referring to was just less than 200 degrees. It normally runs around 160. The most recent "limp" event was not associated with increased temp. It was a lower than normal voltage that was noted this last time. Again, the boat ran fine on the 30 minute ride home after replacing the battery.(My impeller service was not from a MC dealer.)
oops :o I missed the part about not being associated with an increased temp....

JimN
09-28-2004, 01:41 PM
kpb- how long did it take to replace the battery?

Jimmer- My point about "limp mode" or RPM reduction is that if it goes into this mode, shut it off. Since the main thing that will put it into this in the first place is overheat, running it longer will only cause problems. At least with a car or truck, if it overheats it may still have some coolant in to to moderate the temperature swing, unlike a boat with no raw water coming in. Only run it longer if you need to get out of trouble. :rant: :rant: :rant: :D

I just looked in my manual again and in the TBI diagnosis coolant temp circuit description, it says "At normal operating temperature (85C - 95C or 185F- 203F) the voltage will measure about 1.5-2.0 volts." The temperature indicated may not be totally constant, but as long as you don't see the needle get into the 220+ range when it's running, you should be OK. 220 is common in hot areas after heat soak, though.

kpbdmd
09-28-2004, 05:27 PM
It was about an hour after the boat cooled down before I tried to start it. It was another 30-45 minutes before replacing the battery and starting home. Voltage and temp were normal on the ride home.

JimN
09-28-2004, 09:44 PM
Have you taken it out long enough to get the temperature up to normal operating range since the problem reared its ugly head?

kpbdmd
09-28-2004, 10:06 PM
Yes, if normal operating range is achieved in 30-45 minutes of steady 2500-4000 rpm. That was the ride home after the new battery. Prior to the last incident, my ride up river was 45-60 minutes without problem.

jimmer2880
09-29-2004, 06:03 AM
kpb- how long did it take to replace the battery?

Jimmer- My point about "limp mode" or RPM reduction is that if it goes into this mode, shut it off. Since the main thing that will put it into this in the first place is overheat, running it longer will only cause problems. At least with a car or truck, if it overheats it may still have some coolant in to to moderate the temperature swing, unlike a boat with no raw water coming in. Only run it longer if you need to get out of trouble. :rant:
I just looked in my manual again and in the TBI diagnosis coolant temp circuit description, it says "At normal operating temperature (85C - 95C or 185F- 203F) the voltage will measure about 1.5-2.0 volts." The temperature indicated may not be totally constant, but as long as you don't see the needle get into the 220+ range when it's running, you should be OK. 220 is common in hot areas after heat soak, though.Totally agree.

185-203 :eek: WOW - that's hot! I've never had any inboard get over 170 unless there was a problem. Maybe my 85 water isn't warm enough to cause it to go highter. Of course - that is NON-heat soaked temps. I don't usually pay attention to the temps after I shut her down.