cmi headers melted hose

[blueliner]

hey guys went out today and melted my port side hose. the one that connects the Q&Q to the tail pipe. i was cruisinfg along and i started to smell smoke... looked at the water temp gauge 170 where its always at and then a big cloud of smoke. shut her down and smoke is coming from the tailpipe on the inside. i can see where the hose melted. a little bit of water was coming in around the clamps holding the exhaust to the corsa unit. any ideas what would cause this??? anyway crawled home, tech is comig tomoorow to change hose. hopefully won't happen again. also, now that the headers are on, boat seems to run rich especially the starboard side... any thoughts. btw, boat hasn't been able to beat my best speed, pre-CMI headers. (77.6 mph gps 78 pre-CMI.) only have a few hours in her and my tech rewired the trim tabs so that they actually make practical sense, so im relearning that as well. love the imco steering kit, although wish i had the range of motion i use to have. but, it is like driving a cadillac now. hope to hear your thoughts.

[Carl C]

I think you have insufficient water flow to that side. The supply hoses are hard to fit right without kinking them. See if that hose is pinched at all. My top speed didn't improve either like I told you on the phone but I do feel more midrange. You had the factory aluminum manifolds too. Look at how big the ports are. I bet they'd flow more on a flow bench then the headers. My thinking is that the tuned pulses help cyld. evacuation at midrange but that they don't flow any better then the stock exhaust at top end. I'm sorry to hear all of the problems you are having; it makes the problems I had putting mine on look like nothing.

[MOP]

With Q&Q it is important to have very good water flow especially on long runs with the exhaust open, what many do not realize is when you are on open a lot of the water is going down the Y pipe not out the pipe to cool the hose. On a buds boat we made little S/S diverters that slipped over the edge of the Q&Q at the bottom and were held in place by the riser hose, the small strip kicks more water up into the exhaust. Very simple just a piece of .050 S/S 1"X2" with a bend so it sticks up about 1/2" that ended the problem.

Phil

[mrfixxall]

post a pic please,,dont those headers run dry and blend the water at the exhaust tip?

[Carl C]

The headers are fully wet. Here are pics of mine. The water enters the log manifold at the lower left and here is where the problem may be. Your kit contained a straight fitting and a 90* elbow. The elbow caused the hose to kink on mine so I switched to the straight one and it still took a while to get it where there were no kinks at all. Even a partial kink is no good. Blueliner, the other side is tricky too and you should also check it for any partial kinks. I've bit my tongue up til now but it's time to say it - I think you need a new boat mechanic. I have quite a few hours on mine without any problems but your situation reminded me to throw a roll of duct tape in the boat. Blue, could you post a pic from the same angle as mine?

[LKSD]

I think you have insufficient water flow to that side. The supply hoses are hard to fit right without kinking them. See if that hose is pinched at all. My top speed didn't improve either like I told you on the phone but I do feel more midrange. You had the factory aluminum manifolds too. Look at how big the ports are. I bet they'd flow more on a flow bench then the headers. My thinking is that the tuned pulses help cyld. evacuation at midrange but that they don't flow any better then the stock exhaust at top end. I'm sorry to hear all of the problems you are having; it makes the problems I had putting mine on look like nothing.

:yes::yes: My thought too. You may need to fabricate a valve so that you can force more water to that side.. :yes: Jamie / Lakeside

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[blueliner]

The headers are fully wet. Here are pics of mine. The water enters the log manifold at the lower left and here is where the problem may be. Your kit contained a straight fitting and a 90* elbow. The elbow caused the hose to kink on mine so I switched to the straight one and it still took a while to get it where there were no kinks at all. Even a partial kink is no good. Blueliner, the other side is tricky too and you should also check it for any partial kinks. I've bit my tongue up til now but it's time to say it - I think you need a new boat mechanic. I have quite a few hours on mine without any problems but your situation reminded me to throw a roll of duct tape in the boat. Blue, could you post a pic from the same angle as mine?
i know the hose in pic 2 is not nearly as round as yours. its is kinda folded over. could that be the problem??? what size hose is that (diameter)?? should i be able to get that at any boat shop or is it something i should get at an auto parts store??? i will look at pic 1 and see what mine looks like. i will go take a pic and see if i can post it.

[blueliner]

here are some pics. they are both of the port and starboard side. u can see on the port(where the hose melted) the black burnt rubber. let me know if these pics help at all with the diagnosis of what you think might be causing it. are there any concerns with leaving the Q &Q on for an extended period if u r just moving slowly about??

[blueliner]

one more pic... where the hose melted

[blueliner]

The headers are fully wet. Here are pics of mine. The water enters the log manifold at the lower left and here is where the problem may be. Your kit contained a straight fitting and a 90* elbow. The elbow caused the hose to kink on mine so I switched to the straight one and it still took a while to get it where there were no kinks at all. Even a partial kink is no good. Blueliner, the other side is tricky too and you should also check it for any partial kinks. I've bit my tongue up til now but it's time to say it - I think you need a new boat mechanic. I have quite a few hours on mine without any problems but your situation reminded me to throw a roll of duct tape in the boat. Blue, could you post a pic from the same angle as mine?
carl, do u notice the same amount of water coming out of your pipes now that u switched to the cmi's?? on mine it seems a lot less water is coming out when at idle(like when im flushing the engine)

[MOP]

My buddy had his problem at prolonged cruise speeds.

Phil

[Carl C]

None of your pics show where I suspect the problem is, which is where the water supply hose connects to the front of the "distribution tube assembly". Check those supply lines carefully and if yours has the 90* elbow I'd replace it with the straight fitting like in the first pic I posted. Also, yes, if your U hose is kinked at all that would restrict the water flow. It's hard to see in your pic but it seems OK. This needs to have the bends molded in so you can't use regular hose. If you cannot route the supply lines without them kinking then I don't see why you can't use automotive heater hose there. It is 1 inch I.D. Mine seems to have just as much water out the exhaust and I've made a lot of top speed runs and one long cruise at moderate speed. All with the exhaust in "quick" mode. If all looks good then I suppose your water pump could be going but I doubt that. Of course the 4" dia. hose is a marine product.

[blueliner]

None of your pics show where I suspect the problem is, which is where the water supply hose connects to the front of the "distribution tube assembly". Check those supply lines carefully and if yours has the 90* elbow I'd replace it with the straight fitting like in the first pic I posted. Also, yes, if your U hose is kinked at all that would restrict the water flow. It's hard to see in your pic but it seems OK. This needs to have the bends molded in so you can't use regular hose. If you cannot route the supply lines without them kinking then I don't see why you can't use automotive heater hose there. It is 1 inch I.D. Mine seems to have just as much water out the exhaust and I've made a lot of top speed runs and one long cruise at moderate speed. All with the exhaust in "quick" mode. If all looks good then I suppose your water pump could be going but I doubt that. Of course the 4" dia. hose is a marine product.

carl, i noticed after i took the pics that your photo is from the starboard side in the front. i will go back down and take a photo of your exact angle. would a restriction limit my speed??? probably not, but i thought i would ask. also, my rpm's seem to be the same, and also, i think i might need to reprogram the computer cause it appears to be running rich. my guy is coming down to change the hose and the impeller just to make sure. he says the big boys do it every year anyway. granted i only have 80 hours on my boat, but better be safe than sorry.

[blueliner]

here are some more pics... any red flags coming up???

[Carl C]

No, my pics are of the port (left) side. You shouldn't need to reprogram; if anything the headers should lean it out a bit. It's possible the temp sensors are unplugged or damaged which would put you in a rich mode but I doubt it. I have always had soot on the transom; it's normal on the 496. Restricted water flow will not slow you down. Dry headers actually flow better. I have 130 hours and three seasons on mine and will do my first impellor change this winter.

[blueliner]

No, my pics are of the port (left) side. You shouldn't need to reprogram; if anything the headers should lean it out a bit. It's possible the temp sensors are unplugged or damaged which would put you in a rich mode but I doubt it. I have always had soot on the transom; it's normal on the 496. Restricted water flow will not slow you down. Dry headers actually flow better. I have 130 hours and three seasons on mine and will do my first impellor change this winter.
do u see anything out of whack with my pics

[Carl C]

Blue, first I wonder if you don't have your terminology mixed up? You said your port side burned but the pic in post 9 appears to show the starboard side that is burned. Port is left. Both words have four letters. I'm sure not trying to cause any embarassment but isn't the problem on the starboard (right) side? The last pic in post #14 looks like the feed hose is not pinched and pic #4 in post 8 gives a good shot of the "U" hose which looks good. Everything looks good to me in your pics. You might pop off the U hose to look for any restrictions inside the header or Corsa adapter. I can't think of anything else that would cause that hose to burn through other than a lack of cooling water mixing with the exhaust. Maybe someone else has an idea? Something is wrong for sure or mine would have burned through too by now.:confused:

[blueliner]

Blue, first I wonder if you don't have your terminology mixed up? You said your port side burned but the pic in post 9 appears to show the starboard side that is burned. Port is left. Both words have four letters. I'm sure not trying to cause any embarassment but isn't the problem on the starboard (right) side? The last pic in post #14 looks like the feed hose is not pinched and pic #4 in post 8 gives a good shot of the "U" hose which looks good. Everything looks good to me in your pics. You might pop off the U hose to look for any restrictions inside the header or Corsa adapter. I can't think of anything else that would cause that hose to burn through other than a lack of cooling water mixing with the exhaust. Maybe someone else has an idea? Something is wrong for sure or mine would have burned through too by now.:confused:

yea... your right... i am an idiot. i said port, but i meant starboard. LOL!! i do know the difference ha ha. yea my tech is coming over tomorrow to fix her up.he said that due to the adapters and such for the headers, that less water flows through the tips and more goes out the drive now. he is gonna take her apart and see if anything funky is going on in there. thanks for all the input. hope to be back on the water tomorrow.

[LKSD]

Did you ever pull the caps on your heat exchanger & check for junk? ALso did you ever back flush the oil & PS coolers?? It sounds as if the exhaust is not getting enough water thru when it needs it. It also cold be a restriction in the header itself, although unlikely.. Jamie / Lakeside


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[Carl C]

Any word yet? Again, I didn't mean to hang you out to dry on the port/starboard mix-up; I should have put that in a PM. I still have to think sometimes to remember and that's why I said the port/left 4 letter rule. I don't know why right and left aren't good enough. Another thought is that if your right side header was running significantly hotter than the left side then the different values going to the computer may have put you in a rich default mode. I still don't think you will gain much top end though. Keep us up to date please.:crossfing:

[yeller]

Hope you got it all fixed.

I'll be in the water tomorrow. Taking my niece and nephew out. They've been at me all summer. We'll more than likely be going by your place, up to the falls. Look for me if your out. I'll be solo about 3:00 and thought I might blast over to Granville or Bowen Isl for a burger.

[Carl C]

I got the boat out last Thursday and was able to make some speed runs since I had the lake to myself. I made three runs of 74.3. Pretty consistant anyway. I think I picked up about .5 mph. After a high speed run I checked my exhaust hoses and they were only warm; the whole exhaust system was cool enough to hold your hand on. My labbed Bravo 1 should arrive Wednesday and I'm really looking forward to that.:) Yeller, how fast is your boat on GPS? What prop do you run?

[blueliner]

I got the boat out last Thursday and was able to make some speed runs since I had the lake to myself. I made three runs of 74.3. Pretty consistant anyway. I think I picked up about .5 mph. After a high speed run I checked my exhaust hoses and they were only warm; the whole exhaust system was cool enough to hold your hand on. My labbed Bravo 1 should arrive Wednesday and I'm really looking forward to that.:) Yeller, how fast is your boat on GPS? What prop do you run?

well, my tech switched out the exhaust hose... we backflushed it and then water tested and it all seems to be working fine. we also changed the impeller, even though the one in there, my tech said looked brand new. i guess we were wanting to find a smoking gun, to explain what happened, but really couldn't. whats weird is that i had made a run earlier in the week with a buddy that was at least 20 miles with no problems at all. then when this happened i had only been out for maybe 5 minutes before this happened. don't know. still trying to get the water pressure gauge to work. my boat is having some glass work done right now, while i am on the rock. hopefully when i get back, everything will be good as new. with regards to speed. so far the best i have done is 77.6 mph on two gps's since the cmi install. don't think i really have had her trimmed up all the way yet though. hope when i get back i can get back at her. i have a mirage+ 27p (closer to a 28p)that has been labbed by brett at bblades. i want to do some serious testing when i get back and see what my rpm's are like. so far i don't think i have broken 5 grand. i will post results. thinking about a 4 blade??? what do you guys think?? i have heard how much better it runs in rougher water. thats the only thing in these smaller boats... when u get these side rollers and a lot of slop just can't keep up with the bigger boats. speed wise i can take em, but a 22 versus a 29 or so, just can't compete when it gets too rough. will a 4 blade help with any of this??? thanks in advance.

thanks for all the feedback.

[yeller]

Carl, I run a 27p Hydro Q4. I think a 28p would be a better match though. As far as speeds....who knows....I don't have a gps. I have sent the needle well past the 80mph mark...if that's worth anything, but the conditions have to be perfect. I'm not sold on the Hydro for my boat. I was hoping to do some prop testing this year but that didn't happen. I really want to try a 3 blade and the new Turbo's. Hopefully next year I'll do some testing...as well as reprogram the computer.

Steve, you're more than welcome to try my Hydro if you like. Just give me a call. It'll be a touch big for your setup, but should work well enough to give you an idea whether you like it or not. Besides...I've been wanting to try your M+ :)

[Carl C]

thinking about a 4 blade??? what do you guys think?? i have heard how much better it runs in rougher water. thats the only thing in these smaller boats... when u get these side rollers and a lot of slop just can't keep up with the bigger boats. speed wise i can take em, but a 22 versus a 29 or so, just can't compete when it gets too rough. will a 4 blade help with any of this??? thanks in advance.
thanks for all the feedback. I'll let you know! I should have mine tue or wed and it looks like the weather will cooperate for testing. I'll test on the pond first and if my rpms are close enough I'll go for Lake St. Clair and jump some freighter wakes! I have heard that 4 blades keeps the boat more level so will not need to run neg trim or tabs in the rough and it's supposed to do this without sacrificing top end. Too bad you're having these problems during your short boating season. I've topped 75 on a cold day and can now hit 74 easily unless it's steamy hot. Remember I'm on fresh water. Yeller, I'd figure you to be at about 85. Must be fun!:yippie: