Info on tuning OMC 115 turbojet

[crispins]

Hello everyone. I hope this is the correct place to post this.

I have wanted a little jet boat for many years now and saw one for sale last night and bought it this morning.

I am very nervous about it.

I have many questions.

The boat has sat for many years (tagged 2013), it does run and I have a video of it out on the lake running yesterday.

The boat only starts with a spray of starting fluid. I am thinking that may be a choke issue. Any advice?

Can these engines be ran on a hose?

I looked for a manual for the engine on Ebay and they seem to be $70+, is that correct? Is there a cheaper option?

Should I service the jet pump, if so how?

I am a good automotive mechanic and I have a decent understanding of 2 stroke motors.

The lake is 30-45 mins from my house so I would love to be able to tune up the engine and get it running good at my house.

The boat does have new spark plugs.

Advice please and thank you in advance!

 

[racerone]

These motors have fixed timing that does not go out of adjustment.------Carburetion has fixed jets.---------Ignition system does not suffer from any wear items.---------What do you understand a " tune up " to be on one of these ??----------Myself I would start with a compression test.-----That will tell most of the story.

 

[crispins]

These motors have fixed timing that does not go out of adjustment.------Carburetion has fixed jets.---------Ignition system does not suffer from any wear items.---------What do you understand a " tune up " to be on one of these ??----------Myself I would start with a compression test.-----That will tell most of the story.

Well I guess that answered many of my questions.

Whenever I buy anything used I always change everything I can.

Plugs, filters, fluids, ect.

On used Seadoo's I change all the fuel lines.

What should be done on this engine?

How can I change the crankcase oil?

So with the ignition is it an either it works or it doesn't kind of thing?

 

[racerone]

"""-----There is no oil in the crankcase !!!---There is oil in the gear box below the motor.-------This is a 2 stroke motor.

 

[Scott Danforth]

The boat only starts with a spray of starting fluid. I am thinking that may be a choke issue. Any advice?

STOP doing this. you will wreck your two stroke. use a bit of 2-stroke gas in a squeeze bottle but stop using ether

 

[boobie]

The motor does have a primer on it for starting. Check that out. Look at a parts break down.

 

[crispins]

We can end the discussion on this thread as the motor is junk.

30-90 PSI compression.

Currently looking for replacement motor

 

[boobie]

Did you pull the cylinder heads ?? You said you just had it running.

 

[crispins]

Did you pull the cylinder heads ?? You said you just had it running.

No I just pulled all the plugs and did a compression test.

Lowest was 30 psi highest was 90 psi

These engines are bad for throwing rings (so I have read)

Should I pull off the head just to check the head gasket?

I read that there was an inspection cover to view the rings, is that true?

How should I proceed?

 

[boobie]

First thing to do is pull the heads to check for a blown head gasket. Next you can pull the covers on the side of the block to check the pistons and rings.

 

[crispins]

First thing to do is pull the heads to check for a blown head gasket. Next you can pull the covers on the side of the block to check the pistons and rings.

ok - I am thinking about dropping it in the lake and seeing how bad it is first, think that would be a horrible idea?

 

[boobie]

Yes ........

 

[crispins]

Yes ........

Ok - even though you did not give much of an explaination I am going to take your word for it. I will pop off the heads and report back.

If you feel like it would you want to tell me why it would be bad? I have a video of the PO running the boat on the lake the day before I bought it. (the video could be fake)

 

[boobie]

If it now has problems, the more you run it could make them worse.

 

[crispins]

If it now has problems, the more you run it could make them worse.

I decided (after being recommended by members here) to pull the top end of the motor apart tomorrow and see what kind of shape it is in.

 

[boobie]

Well, what happened ??

 

[crispins]

Well, what happened ??

Sorry man - I have another thread here with the title of "help me re-ring engine"

I pulled it apart, needs a piston, new rings, possibly one head.

 

[boobie]

Thanks for the come back.

 

[Jon NL]

Do you have the link to the new thread