Help me to re-ring my engine.

[crispins]

After much research and a few different threads here I believe that re-ringing my motor makes the most sense.

I want to use this thread to help me to get this motor pulled, tore apart, fixed, reinstalled, and adjusted.

Here is some information.

The boat is a 1996 Sunbird Sizzle 14' Jetboat with an OMC 115 turbojet

The hull and interior is in very good shape.

The boat was last tagged in 2013

I paid $1,500 for it.

Compression was between 30-90 PSI on all 4 cylinders

I pulled one head off (the easy one to get to) and the cylinders look good.

The motor spins over very smooth when turning the flywheel by hand,

Here are the pictures










My goal is to get this one the lake for the 29th of this month.

I have a full set of tools and an engine hoist.

I plan on pulling the powerhead out tomorrow and disassembling it so I can get a list of parts I need to order.

How does this motor look to you?

Yes I do know that a full rebuild would be best but this is low budget tech that I need to work with.

 

[jakedaawg]

I certainly hope your set of tools contains an oem manual. If so, ask away.

 

[ondarvr]

It's really not worth it to just put new rings in, if you take it apart you should do it all while you're in there.

​If 30 PSI is correct, there would be some serious damage or wear, which means boring it oversized and all new pistons and rings, and going that far means you should replace all wear items, It would be a complete rebuild.

​

 

[77kingfisher]

Is it safe to assume its a 2 stroke? If so have you tried a de-carb yet they might just be stuck and need to be freed up that's a super low budget repair. And even if it dosen't fix it "enough" it will make disassembly a hell of a lot easier.

 

[crispins]

I certainly hope your set of tools contains an oem manual. If so, ask away.

Yes it does, all 225 pages.

 

[crispins]

Is it safe to assume its a 2 stroke? If so have you tried a de-carb yet they might just be stuck and need to be freed up that's a super low budget repair. And even if it dosen't fix it "enough" it will make disassembly a hell of a lot easier.

yes 2 stroke.

What is this decarb? Is it worth trying?

 

[crispins]

It's really not worth it to just put new rings in, if you take it apart you should do it all while you're in there.

​If 30 PSI is correct, there would be some serious damage or wear, which means boring it oversized and all new pistons and rings, and going that far means you should replace all wear items, It would be a complete rebuild.

​

Can you explain a little further?

The pictures I posted were of just one side of the motor. That is the side that has 90 PSI, the other side had the 30 and 60 PSI.

The cylinders on this side look pretty good to my eyes.

 

[jakedaawg]

Pull the other head off before you bother pulling the motor. These little jet boats are a pain...might get lucky and just have a blown head gasket. This is assuming your compression guage was installed correctly and is of decent quality.

 

[jakedaawg]

A decarb will not solve 30-60 psi ever.

 

[175se]

Whats that stuff next to the pillow in the cyl head?

 

[crispins]

Pull the other head off before you bother pulling the motor. These little jet boats are a pain...might get lucky and just have a blown head gasket. This is assuming your compression guage was installed correctly and is of decent quality.

The compression gauge is an "autozone rental" so not sure of the quality.

I will pull the other head tomorrow, it is not as easy to get to. I am also hoping that it is a bad gasket on that side.

 

[crispins]

Whats that stuff next to the pillow in the cyl head?

Not sure what you mean at all, which picture?

 

[jakedaawg]

It's easier to pull the head than to install the powerhead on some of these little jet boats.

 

[racerone]

I do not believe you are going to make the deadline of May 29.-----As i have stated before you need to take this apart.---Measure the parts.---Decide on a fix.-I have pulled the engine out of my " Fling " jet boat.---Have a good idea what needs to be done !!

 

[175se]

picture #3 and 4 in the corner.

 

[crispins]

how does the head gasket look on that head?

Does it look like it was sealing correctly?

Also how do I connect the engine hoist to the motor to remove the head?

Do I need to order an eye that connects where the flywheel nut goes?

 

[interalian]

Also how do I connect the engine hoist to the motor to remove the head?

Do I need to order an eye that connects where the flywheel nut goes?

Get an harmonic balancer puller and some suitably long 5/16" UNF bolts. Leave the flywheel nut in place, snug the puller's center bolt down, wrap a chain through the puller and lift.

 

[crispins]

double post

 

[crispins]

What is the best way to remove those gaskets?

I do not want to scratch up the finish.

 

[crispins]

Get an harmonic balancer puller and some suitably long 5/16" UNF bolts. Leave the flywheel nut in place, snug the puller's center bolt down, wrap a chain through the puller and lift.

Perfect thank you!