One manifold is hotter than the other...

was it always running hot?

Eric, I'm pretty sure that these hoses have been like this since I got the boat.

I ran it in the driveway for about 20 minutes at idle with the garden hose hooked up. It seems to be staying a lot cooler now. I won't know for sure until I water test it this afternoon but I'm feeling pretty confident that I found the problem.

I would say that the 3 1/2" hose was reduced to about a 2" - 2 1/2" hose the with the way it was all bubbled up and corroded inside.

The JB weld fix seems to have worked great. The side that needed fixing looks like the side Eric didn't fix, the side that he fixed was the side that was running cool. I can't believe how thin the fiberglass is on these invertafow's.

The hoses went on a lot easier than I thought they would. I soaked them in some hot soapy water before I started and used a spray bottle with soapy water to soak down the risers and inlets. No problems with the wired hose.

I ran the garden hose to the hose before the thermostat housing and put buckets under the new hoses and the water collected seemed to be pretty close to equal.


I think the pictures tell the rest of the story.

Inside of the hose on the side that was overheating


Another shot of the inside of the hose on the hot side.


Hose from the side that was running cool.


New hoses installed



I think the hoses are bubbled up on the inside from when the previous owner overheated the engine when he forgot to put the strainer cup back on...

My theory now is that this badly damaged hose combined with the restriction at the inlet on the invertaflow caused by the collapsing fiberglass was causing enough restriction that the water chose the path of least resistance and was going through the manifold on the somewhat good side and avoiding the bad side. I will test it out in the driveway tomorrow morning and take it to the lake and give it a good test run if everything looks good.

I hope this is was what was causing the problem.

Randy_in_Ohio wrote: I'm thinking it may make a hell of a mess firing it up with the muffler removed...?

Super loud anyway Randy. I washed more towels working on my boat.   

you need to fire it up at this point and see what kinda flow you get from that hose, look down inside the IF, for any restrictions. that area that you have JB welded is the area where i took a piece of pvc as a form and wrapped glass around it to create a surface for the hose. all of that was missing when i removed the hoses...it had to go somewhere at one point. that 3" hose is not going to create the restriction, the bubbles you are feeling is probably from the hose heating up.
Something caused that inlet pipe to break down and corode away, I would really fire the boat and compare the flow side to side, remember the risers were not replaced and judging by the flow when you remove the hose from the manifold, its not a flow problem. I really think the risers are restricted

I am missing a glove, just one, its white with glitter on it, maybe down in the hose?

Randy, take the hoses off at the invertaflow and fire the boat and make sure the water is not restricted in the risers, make sure there is nice flow from both hoses. and then look to the invertaflow
the risers were pretty coroded and i had to take a good cut on the gasket surface, moreso on one than the other????

Randy - another idea to help pinpoint this - when you have the invertaflow off, run the garden hose into the hose going to the thermostat (take it off RWP output port). Then you can see how even the flow is from L-R. At least it would satisfy your curiosity about the adequacy of the plumbing.

I am not getting any pulsating on the hoses anymore.

When I disconnected the hose from the transmission cooler last night all the water that was in the hose fell out the intake as soon as I pulled the hose. if there was a leak, wouldn't the water be leaking out while it sat and not create this vacuum that holds the water in the hoses?

Either way, I really think this exhaust hose between the starboard riser and the invertaflo needs to be replaced. The port side hose is hard all the way around and this hose is really soft in spots. I can push on it with my pinky finger and it gives.

I think I am going to try to take the invertaflow off tonight and take a look at it even if I have to out it back together with the wired hose.

If the pump was pulling air I think I would be seeing a lot of bubbles going through the clear hose running to the OJ seal. I discussed this with Vice also and he seemed to think the pump was probably fine.

the hose was pulsating going to the port side, may want to check out further or buy the rebuild kit that includes the shaft seal

you know im sitting here thinking, on one of the sides i had to re-glass one of the three inch inlets because alot was missing so the hose would fit snug, maybe just maybe the old pieces are in the invertaflow.
I spun that thing around like a 20 year old and nothing fell out.
Randy, time to run some straights
but then again, how hot is it getting?

Let me check the '93 sport here before you tear anything apart.

I personally do not think you have a problem.

Randy - I assume you have the intertaflow. It took two of us, but we were able to wiggle it enough to remove the muffler w/o removing the risers. Loosen the clamps well & use a screwdriver to break the seal of the hoses to the risers.

Hope it is your hose, you must be frustrated. Maybe you should just hacksaw thru the hose, sounds like it is bad anyway.

I wasn't able to get a laser thermometer. I went to two different Harbor Freight stores and they were both sold out of them. Must be a good deal, I got a raincheck and they said they would call me when they come in.

I took the boat out last night but got out a little late to really run it hard. Your only aloud to run fast until 8pm. I took a couple laps and it seems the same with the Perko flush removed. I could leave my hand on the port side manifold all day but the starboard side I wouldn't want to leave my hand on for more than a few seconds. Running it at idle seems to cool the starboard side down to about the same temp as the port side after a half hour or so.

I did notice a little bit of air bubbles running through the clear line to the OJ seal now that it is on the hose going to the port side manifold. No air bubbles in the strainer cup. Maybe it is pulling some air through the pump?

Randy, another thought, there really is not any guidelines on manifolds, old manifolds do get restricted and the water sticks around longer to transfer heat, on fresh clean manifolds the water is barely restricted and flys through these manifolds unabling them to transfer heat. temp readings will help to determine what is correct and what isnt, they are exhaust manifolds and typically are the hottest part of the engine, they are cast iron and the same as on cars and cars will see 700 degree temps. are we chasing our tail here?

I think I may try removing the Perko flush unit and see if that may be restricting the water flow.