98 stx 750 blowing exhaust hose

[hondaws]

we have a 98 stx 750 here and we can't keep it from blowing exhaust hoses. we have gotten the life of the hose extended a little bit by restricting the water flow forcing more water through the exhaust. this however slows the boat down and the hose still blows out after a few hours of riding. we have also done the update of drilling the brass restricter in the exhaust.

[Bryan Glynn]

Are you applying any grease or something to the inside diameter? Have you tried a larger clamp?

[hondaws]

there isn't anything inside the hose, the hose itself is actually coming apart, melting

[Bryan Glynn]

About the only thing i can suggest is to remove the entire exhaust system, blow out all the fittings, passages and lines, looking for obstructions. You have one somewhere.

[hondaws]

We have had the complete exhast apart four times and the top end off the engine twice. There is no restriction in the exhaust or the top end of the engine. All cooling hoses are not cloged.

[gigi]

If indeed all the cooling passages IN and OUT of the muffler are open, I'm guessing there must be a hose improperly routed. It's easy to do. Are you sure you're not sending water in the wrong way, and not cooling the actual pipe? There's only one way melt a hose, it's by not cooling the pipe. I don't think improper engine mixture would do it, or the engine would blow up first...

I'd suggest making 100% certain that you follow the shop manual for connecting the hoses where they should go. Also make sure that the water outlet near the end of the pipe [next ot where the hose probably blows] flows water out over the top of the pump. You should be able to see it CLEARLY with the engine idling in water. Maybe that's where your obstruction is, not in the hose, but in the "spout" located above the jet...

Good luck.