Mercruiser 7.4 won't go forward after hose failure

[FishWagon]

Hello all,

My family and I were just out on our 1989 Chaparral 2550 SX Sport, 7.4 Mercruiser Bravo 1 drive.

We were moving along slowly, pulling young children on a tube when we saw and smelled smoke coming from engine bay. It was rubber in nature.

We stopped and looked around and found nothing at all. After a little while, we restarted, and after the smoke did not return, we went on our way. However, we had a problem going forward intially, but then everything went great. We did a high speed run, and the boat ran great.

We stopped, and couldn't get it into forward gear again. So we beached her, and let the kids play while I poked around. Could not find anything amiss.

I decided to just get her out of the water, so using reverse only, we were able to make it a good distance across the lake, when someone towed us the rest of the way.

Engine runs fine, gauges show all is well, so I'm was sure it was the outdrive.

When we got her on the trailer and out of the water, I noticed a hose from the engine bay to the drive was all torn apart. It's a significant hose, about 2.5" across, that simply failed. My question is what does this hose do (cooling water?) and what could have happened and if I am looking at an expensive repair.

Thanks a bunch! Have a great day.

Rich

 

[Fun Times]

Re: Mercruiser 7.4 won't go forward after hose failure

Any way you can get a photo of the hose and a over all shot of what the hose is hooked to at both ends??? That might help a little.

 

[HT32BSX115]

Re: Mercruiser 7.4 won't go forward after hose failure

Howdy,

You didn't offer much to go on. You might post a picture of the hose.

The only 2.5" hose I can think of is the one that goes from the transom to the sea-water pump.

There may also be other hoses that size in there related to cooling water and one of them may have been rubbing on a pulley etc (hence the rubber smoke)

A picture is worth a thousand words....

As long as you didn't burn anything up or overheat the engine the replacement shouldn't cost much, but remember most marine service places charge $75-100 per hr.


Regards,

Rick

 

[FishWagon]

Re: Mercruiser 7.4 won't go forward after hose failure

Yeah, here's one right here.

From looking at the parts breakdown, it looks like the exhaust bellows. I'm thinking that when this let go it damaged the shifter cable?

Hope the pics are ok, it's nighttime here now.

 

[HT32BSX115]

Re: Mercruiser 7.4 won't go forward after hose failure

Well,

you may be getting your terms off a little.... The exhaust bellows is down in the gimbal.

If you burned up one of the exhaust hoses, that's different. it's also a 4" hose and that would probably get hot due to loss of cooling water from the riser.

The picture will help.

If you use a picture hosting service like Photobucket etc, it usually works best. You also should try to size it so we don't have scroll all over to see it.....

take a few that are in good focus...

 

[jtybt]

Re: Mercruiser 7.4 won't go forward after hose failure

That's your exhaust bellows. By itself, it is no real big problem if it ruptures. It's the cause that is the problem. Also, the exhaust tube shouldn't look all greasy or burnt up on the inside. Which is it.

There are a few reasons the drive is stuck in reverse. Cause could be the cone clutch or shift cable.


Check drive fluid for water contamination on a regular basis. Just loosen the drain plug and let a few drops out to read.

 

[Fun Times]

Re: Mercruiser 7.4 won't go forward after hose failure

It could be the shift cable is damaged even though it looks ok from the out side. The exhaust bellows does look like it got hot at one point, And you are going to want to find out why also. Has this boat ever been serviced by a mercruiser shop before??? Like water pump impellers, Oil and filters and stern drive removed for service with oil changed in drive, Ect,

 

[Bondo]

Re: Mercruiser 7.4 won't go forward after hose failure

Ayuh,... For some reason, it was run Without water,...
That Burnt up All the Rubber parts in the exhaust system,+ it's My Guess,...
The shift Cable was touching the y-pipe, which Melted the Shift Cable Housing...

You need to get the boat to a Marina to get an Estimate for repairs...

 

[FishWagon]

Re: Mercruiser 7.4 won't go forward after hose failure

Thank you everyone, I appreciate it very much.

Rich