LPG Regulator freezing up on 192 ski nautique

[Callumohare06]

Hi, I’m looking for advice on my next step to trying to fix our boat. We have a 192 ski nautique 2008 which was converted to lpg by a different owner. The boat ran fine last season but this year we’ve had issues with the lpg regulator getting too cold and frosting over. This doesn’t happen all the time and seems to be a bit random to happen. It causes the boat to lose power until the regulator gets back to a regular temp. We’ve gotten the lpg conversion part of the boat serviced and given the 100% by a mechanic but he did not fix the problem. (He didn’t know about boat engines just the lpg on them) It worked a few outing before happening again. We replaced the thermostat in the engine to no avail. I don’t think it’s the water pump failing as I imagine the engine would overheat before the regulator becomes and issue and temps are normal on the engine. Any help or advice would be greatly appreciated.


conversion #troubleshoot fix #issue

[Callumohare06]

Here’s a photo if anyone is interested

[Rednucleus]

My grandpa had a car converted decades ago and it did this. I remember there was a hot water line to his conversion from the radiator, and something failed allowing it to get too cold - may not apply to marine but decades later I can still picture how frosty that got before he fixed it. Is there a water feed on yours?

[Callumohare06]

My grandpa had a car converted decades ago and it did this. I remember there was a hot water line to his conversion from the radiator, and something failed allowing it to get too cold - may not apply to marine but decades later I can still picture how frosty that got before he fixed it. Is there a water feed on yours?

So the way it works is that it takes the water that runs from the Lough, goes through the engine (heating it up) and then goes through the regulator to heat that up. I think if the water pump for that wasn’t working then the engine would overheat before the regulator becomes an issue.

[Rednucleus]

Is that top hose the water line? I would feel the in & out lines see if they are warm, just like feeling hoses going to a car heater core. I assume there's not an additional pump pushing water to the regulator. Is there some kind of valve that regulates water flow through the regulator? I might start by unhooking the water line to the regulator and see what kind of flow you get. I am assuming this is not a closed cooling motor.

[Callumohare06]

Is that top hose the water line? I would feel the in & out lines see if they are warm, just like feeling hoses going to a car heater core. I assume there's not an additional pump pushing water to the regulator. Is there some kind of valve that regulates water flow through the regulator? I might start by unhooking the water line to the regulator and see what kind of flow you get. I am assuming this is not a closed cooling motor.

that line is for fuel but there are 2 water flow in and out pipes. When it’s freezing up they are both cold. I don’t believe that there’s an additional pump for the water. I’m not sure if there’s a regulator for the water flow and unsure where to check. I’ll unhook the waterlines once she’s out of the water. Also it’s not closed cooling . Thanks for the reply!

[Rednucleus]

Where do the water lines come/go on the motor? Are they hoses or metal lines and how big/diameter? I would be most suspicious of a blocked line. I might start by pullling one line at a time off the reguator, start it and see what kind of flow you get.

[Callumohare06]

Where do the water lines come/go on the motor? Are they hoses or metal lines and how big/diameter? I would be most suspicious of a blocked line. I might start by pullling one line at a time off the reguator, start it and see what kind of flow you get.

They are all rubber lines, I have a few images to show where they go into the engine and the size etc. I’d agree that there could be a blockage but I don’t know if I should check while the boat is on the water. So far the boat can run for about 10minutes before losing all power.

[Rednucleus]

You could run it on the trailer with a fake a lake hook up. Is the one you are holding off the ex manifold?
In your very 1st pic 1st post there's a blue solenoid? 180 degrees opposite the fuel line - what's for??

[Callumohare06]

Where do the water lines come/go on the motor? Are they hoses or metal lines and how big/diameter? I would be most suspicious of a blocked line. I might start by pullling one line at a time off the reguator, start it and see what kind of flow you get.

Hi mate. I took the pipes off and they did not have debris. Regulator was clear aswell. I was almost giving up for the day and decided to try turn boat on and give it 3000rpm. After 20 seconds went and checked regulator and it was finally getting hot. Unsure what the reasoning is for this. Would love to hear your insight. (In previous we’ve had days that were fine and other days it froze up) thanks

[Rednucleus]

Does it freeze up when running at speed or only at idle? I alway enjoy trying to figure out how stuff works that's new tome - enjoying this thread! Also check that hoses don't have a sneaky kink somewhere.

[Callumohare06]

Does it freeze up when running at speed or only at idle? I alway enjoy trying to figure out how stuff works that's new tome - enjoying this thread! Also check that hoses don't have a sneaky kink somewhere.

it’s so strange, once the regulator gets hot it stays hot. I was at low speed (5knots) for at least 15mins and there was no sign of it getting too cold. I think it must only freeze at low rpm but usually when we put the boat in the water we have to go slow for 10mins before reaching an area to go high rpm. There’s definitely no kinked hoses I’ve ensured that. I just need to figure out why it needs that rpm at the start to get going. Last summer this was not an issue.

[Rednucleus]

Mayb you have some sneaky air leaks in your water lines somewhere. check all hoses/hoseclamps sea strainer if you have one. If you can run motor in neutral, try bumping up to 2500rpm for a minute after launch - may help purge air.