1998 Ocean runner 150 - sputters and break-up when hot.

[lightning2]

First off this boat runs strong when first run out cold. Gets up on plane and is fast.
Boat runs great going out, lots of power, no issues. Shut off and restart after about 5 minutes, breaks up (running on half cylinders) surges at idle and no ability to clear out or run hard with throttle added. At best you get some bursts of acceleration, more often just breaks up and sputters. Can hobble back to port at 3 mph. This will also happen after a hard run and then a period of idling, 5 min in no wake zone. The marina says that the motors checks out as ok and can?t find the cause.

The following has been changed, or isolated to not be the cause. First ran with alternative fuel tank to isolate not bad gas, changed power pack, changed VRO oil pump, changed Stators, disconnected the cylinder cut out switch. Mechanic tells me he has had the carbs all off, and checked gasket leaks. He found the old stators to be burnt. However after all of this still no fix. Motor acts the same.

I've seen others with claimed similar problems, but no posted solutions.
Not sure what there is left.
I?ve read were one guy had similar runs good then bad when hot tied to a head gasket, and see another talking about bad coils and wires. Not same model motors so don?t know how well these issues tie together.

Any help is greatly appreciated.

 

[jonesg]

Re: 1998 Ocean runner 150 - sputters and break-up when hot.

OK you need a timing light and an infrared thermometer,

take it out and get it to act up, shoot the heads with an infra red thermometer to see if its running too hot, then put a timing light on the plug wires and see if you have dead spark, I would suspect the port temp sensor if one bank has no spark.

If all the cylinders are firing then consider vapor lock, you can test for this.
Run it hard but don't shut it down until it has idled for a few minutes to cool down.
Before restarting, pump the bulb up to fill the bowls with cold fuel.
If its still balky, shut it down and remove the hood to cool it down and try again.

Did they do a compression test?

 

[lightning2]

Re: 1998 Ocean runner 150 - sputters and break-up when hot.

Thanks for the suggestions. I will try and perform those tests as soon as I can. How hot is too hot when measuring head temperature? I'll have to go buy an infra red temp gage.

Yes compression test has been done cold and it test out ok. It has not been done hot. I saw one post where a guy had low compression when hot, but tested ok at cold. It turned out to be a headgasket issue.

Thanks Bob

 

[tashasdaddy]

Re: 1998 Ocean runner 150 - sputters and break-up when hot.

tstats, should start to open at 140* and not get over 175*

i keep on of these on my boat. http://www.harborfreight.com/infrared-thermometer-93984.html

yours does not sound like a head gasket, it sounds electrical, power pack heating up and failing.

do the test with timing light, i just shoot it at my hand, and watch for intermitent spark. i will bet you are dropping atleast one cylinders spark.

 

[bob johnson]

Re: 1998 Ocean runner 150 - sputters and break-up when hot.

that motor does not have a head gasket...it uses O-rings...the rest of the head is aluminum to aluminum.. and sealant is used to seal water passages.


bob

 

[lightning2]

Re: 1998 Ocean runner 150 - sputters and break-up when hot.

OK took the boat out twice this weekend. It ran pretty good Saturday and the problem did not present itself. Took iot out tonight and I got it to act up again.

Did sonme tests as suggested both days. Put the itmeinglight on each plug wire while at idle to start to baseline. All cylinders were firing. While at idle the top of the head at all cylinders measures between 147 and 152 F.

Ran it down teh lake and before shutting down, the head temps were a bit lower int eh 138 -140 range and then climbed back up while idling.

Ran it today, shut it down 10 minutes then started idling back towards the dock. Seemed ok then gave it a little bit of power and the engine started breaking up. When put in neutral it would come down to normal, then rev up past 2000 rpms and was breaking up. Put the timing light back on. All cylinders where triggering the light, so using this as a meaure says I'm getting spark all cylinders, however all three port side cylinders were not firing and head temps were well below 100F, I'd say high 80's. Could hold my hand on any one of the port side cylinder heads indefinately.

When shut down if I pumped the ball and restarted it seemed to help. But if I backed off it would break up again.

Any thoughts?

Thanks Bob

 

[jonesg]

Re: 1998 Ocean runner 150 - sputters and break-up when hot.

"All cylinders where triggering the light, so using this as a meaure says I'm getting spark all cylinders, however all three port side cylinders were not firing and head temps were well below 100F, I'd say high 80's. Could hold my hand on any one of the port side cylinder heads indefinately."

So the timing light flashes but all port cyls are cold.
Disconnect shift interrupt switch. If no improvement,

Time to visit autozone and grab a $10 spark tester, set the gap to 7/16th inch , see if you get a strong spark, I doubt you will.
You could be getting spark but its too weak.
Examine plugs when it does this too, look for wet fuel on plug tip.
Tash is probably right, powerpack breaking up when heated.

 

[lightning2]

Re: 1998 Ocean runner 150 - sputters and break-up when hot.

Yes timing light triggers but cylinders are cold. The mechanic already changed out the power pack as one of the first changes. And the problem was still there. I disconnected the shift interrupt switch once before and pushed in the button manually. It broke up even worse when that was depressed so I did not think that was it.
The mechanic had pulled one of the plugs previously after it acted up and stated it was very wet. I did not pull one last night.
I?ll have to buy one of the spark gap tools.
As bad as this sounds I have not changed the plugs yet, but I would think that if they were bad that the engine would never run right. Every time the boat sits for a while it will run fine again for the first run.
I don?t get to work on it much myself due to time.
Thanks for the suggestions.
Bob

 

[bob johnson]

Re: 1998 Ocean runner 150 - sputters and break-up when hot.

I had a two cylinder that started runnign very poorly. I didnt know then as much as I know now.. i fiddled and checked wires and compression...finally changed the plug in the non fireing cylinder and it ran prefect...

never really thought that plugs would go bad like that....but obviously they do.. and it is an easy cheap fix...

of course most people would rationally think that three on one side wouldnt be bad!!!!! while the three on the other side work so well

bob

 

[bobwirg]

Re: 1998 Ocean runner 150 - sputters and break-up when hot.

OK the final fix for this was a change to the OSI sensor. This was rediculously frustrating and the marina never fixed it over two years. pretty bad. The OSI did teh trick. Updating this post so others will see the correct fix, as it was hard for me to find the righ solution.

Former Lightning2

 

[CatTwentyTwo]

Re: 1998 Ocean runner 150 - sputters and break-up when hot.

Glad you finally got it fixed and thanks for taking the time to come back and let us know what the fix was. I wish we would see that more often.