Jetcraft Hobie Jet Fishermn

[RedBarron55]

Today ended up being beautiful Here in Navarre, FL!
I got a little bit of the fiddly bits taken care of.
I got the fuel gauge working and reinstalled and also got the plumbing to the built in tank back together.
While I was at it I also installed a Moeller fuel filter and separator to keep the wooglies out of the carbs.
I wound my way up into the console to see if there was a warning buzzer for over heat ans there is none I can find so I guess I will have to track down the wires and add one.
The boat also has an in dash temp gauge and I have ordered a sender for that as well but it hasn't arrived yet.
Does anyone know just where this should screw in?
I would hate to be on the wrong side of a stuck thermostat and thinking I was OK while burning down the engine.
I think that moving the battery under the console and using the built in tank will shift the CG forward and raise the stern a little for more clearance for that 7.5 inches from the water inlet on the engine.
One less thing to flood the cylinders.
I did not get a change the check the water and run the engine today wanting to give the epoxy an extra day to harden in this cool weather.
Let me know if anyone knows for sure about the buzzer or the variable sending unit.
The temp switch is in the head, but I have not yet traced the wires.

 

[RedBarron55]

Bad news!
With even the barest trickle of water going in from the hose the water still ends up getting into the #3 cylinder.
Cracked block or head problems?
Any suggestions?

 

[RedBarron55]

Well I have replaced the exhaust manifold gasket and fixed a bad helicoil installation as well as pulled the head, had it surfaced and reinstalled with a new head gasket.
As an aside I found the head bolts difficult to remove and had a lot of corrosion in the threads and on the bolts.
The bottom port side I bent a 1/4" drive extension gettin git out.
Needless to say I chased all of the threads and got new grade 8 bolts.
Since 2 3/8" X 5/16 -18 were not available I got 2 1/2 and cut them down. I found several different types of bolts in the head two late model stretch bolts , some hardware store 2 1/2 " grade 5 and the rest seemingly original for the motor.
With the lack of care in the head bolts and the dirty screw threads I doubt that the head was torqued correctly
I hope that this is where the water was coming from that was getting into the #3 cylinder.
I could see no cracks in the cylinder walls and there was no water in the intake side so here are some crossed fingers.
While working I decided to pull the pump and inspect. In doing this I wrung off one of the pivot bolts on the bucket and now I have to wait on the replacement and get the remaining bolt out of the housing too.
I went ahead and pulled the rest of the pump and found the impeller and wear ring in like new condition with no pitting, scratches or anything. The only thing was some small amount of surface corrosion.

Should I paint the ID of the wear ring when I have finished cleaning it up?
A fairly heavy coat of black epoxy might protect the bare aluminum and build up the surface slightly.
Any thoughts? Anything else I should do while I have everything apart?
Is there any advantage in smoothing out the steering nozzle, it seems to be a little rough inside?
I think I will wait until I get the nozzle reinstalled to install the brand new Cobra Jet Steering rudders so I can make more certain I get them straight.
So far, other than that little water in #3 thing everything is looking good.

 

[nighthawking]

I have cleaned the carbs and found some water in the lower carb and less in the 2nd carb.
I think there was water in the 2nd carb, but since it feeds the enrichment valve it probably was fed there so was less left.
The water I saw in the bottom carb was probably enough to be sucked into the main jet when the throttle was advanced.
I haven't had a chance to run the engine again to see as I need to make an adapter for the cooling water to keep from blowing off the ride plate.
I have been luck (?) since I was using the flush inlet to run the engine (mistake).
I also learned that is you turn up the water pressure you will fill the cylinders and hydraulic the engine.
Hopefully I have been lucky and not damaged the motor.

Also I have decided that this boat is heavy riding lower in the water than it should.
In the rear on both sides there are large square chambers most probably for flotation and they seem to have been glassed in with polyester mat. This mat has separated from the epoxy hull (probably because the mold release was not cleaned completely)
These have listed and the bilge water is under it. If my suspicions are correct the foam within is saturated and needs to be removed.
My plan is to take a vibrating saw and cut that loose "flange" off and clean it up and reglass it with epoxy and cloth as it should have been in the first place.
Before that I plan to cut the top off (square) and pull out and replace the foam. While I am in there I will glass the seams again with cloth and epoxy to make sure it is sealed. Then after refilling glass the top back on.
I hope that the flotation under the floor in front is OK.
Does anyone know how to tell without cutting a hole?
Perhaps I can install an out of sight access hatch under the console.
I would weight the boat and trailer, but there is not a nearby scale and I don;t have the weight of the trailer.
The empty boat should weigh about 875 lbs.

Have you had any issues with the onboard gas tank leaking?

 

[RedBarron55]

Yes I have had problems with the aluminum tank leaking and have replaced it with a plastic tank.
It was a little problem to get it out (in two pieces!) and I had to cut into the flotation foam to make a space for it.
I replaced it when U had the engine out and rebuilt it.
I have been side tracked a great deal with the rebuild and other trips etc. and when the Virus abates it will be time for fishing and boating to make up for lost time.
I have added a remote control trolling motor to the front and Garmin fish finder / GPS and all I need is to do the final tuning on the water and then git er' done.

 

[nighthawking]

Yes I have had problems with the aluminum tank leaking and have replaced it with a plastic tank.
It was a little problem to get it out (in two pieces!) and I had to cut into the flotation foam to make a space for it.
I replaced it when U had the engine out and rebuilt it.
I have been side tracked a great deal with the rebuild and other trips etc. and when the Virus abates it will be time for fishing and boating to make up for lost time.
I have added a remote control trolling motor to the front and Garmin fish finder / GPS and all I need is to do the final tuning on the water and then git er' done.

How on earth did you get it out? I like having it centered low in boat, but I'm having to use a 5 gal portable all the way back as the main one leaks. I also added remote trolling, leds front and rear. I have been working on it for 4 years or so and am almost ready to put it in the water. Sure would like to fix that tank tho. Pic is before mods.

 

[RedBarron55]

Your boat looks nice!
As to the tank it is a "^*@#" to get out!
First you need to empty the tank! then you need to get it dried out.
It is held in place by the fiberglass and foam etc about an inch thick aft of the tank.
I used an oscillating tool and saw blade to cut it out.
Then there is a lot of cursing and head scratching as you need to put some major force on some things.
I blew air from a shop vac through the tank for a good while and also flushed out with water and a pump before that.
I used a come along hooked into the fitting hole to pull the tank to the rear first.
After getting it loose and pulling it back I cut the top that I could get to off and cut the sided so that I could fold the tank up, cut it off and them pull again.
I had room to do this because I removed the engine and pulled the controls and wiring to the side.
I will post some pictures of what I put back in later.

 

[RedBarron55]

 

[RedBarron55]

I doubt that you can remove the tank with the engine installed and I am certain that you can't slide another in place with it in the way.
Not a lot of room to work with in there.

 

[Leo Young]

I have a Hobie too. Is there another option than the 90 merc power head that will marry to the jet drive?