Question on Manifolds/risers

M

micadk

New Member
Jul 27, 2007
18
Houston TX
Boat Info
1996 440 Express Bridge
Engines
Cat 3116 TA
Hi everybody. I am sure this has been covered a time or two, but I could not find the answer I am looking for.
So here goes. I have a 2004 260 Sundancer, 350 Mag MPI, Bravo III drive.
Friday I was getting the boat ready for the weekend. I normally start it in the driveway and check everything out. I made sure the muffs were on good, water flowing, as I walked back to the garage, I noticed it did not sound the same. Sort of a gurgle sound. I got under the swim platform and checked things out. The starboard side was not putting out as much water as the port. It was also noticeably warmer . I could hold my hand in the stream, but it was hotter than the port side. I got in the ER and checked the riser and manifold by touching. I could hold my hand on them, but they were hotter than the port side. I do not have a infared temp thing, and will have to get one now.
We went to the lake anyway. Things seem to run good, and no overheating issues. I ran up on plane for about 5 minutes, then shut it down and check it out. I could still touch the manifold and riser, but it was hotter than the port side. The rubber exhaust hose did not feel hot. I know there is water coming out, just not as much.
Anything to do short of pulling the risers and manifolds? I operate mainly in brackish water, but will go into Galveston bay. I flush the engine EVERY time we come back in. Impeller was changed last September, I have good water flow.
 
Damn man, what an ordeal! I am glad you finally got that fixed. My problem is this just started Friday. I am not overheating, and no work has been performed prior to this. I replaced the impeller last September, but nothing has been done recently. I have plenty of water flow, and good PSI.
I ran the boat on the muffs, that is where I discovered the problem. I ran it at the lake Friday, and checked it, then again checking after a 5 minute run. I am just going by visual and touch, no IR numbers.
 
Damn man, what an ordeal! I am glad you finally got that fixed. My problem is this just started Friday. I am not overheating, and no work has been performed prior to this. I replaced the impeller last September, but nothing has been done recently. I have plenty of water flow, and good PSI.
I ran the boat on the muffs, that is where I discovered the problem. I ran it at the lake Friday, and checked it, then again checking after a 5 minute run. I am just going by visual and touch, no IR numbers.
 
H2ONUT said:
Another good read...

http://www.clubsearay.com/forums/viewtopic.php?t=4656

Member "Playdate" has been very good working with us on these issues. I'm sure he will chime in and throw in his thoughts.
Click to expand...

H20Nut you are in charge of helping him. I am off to get married this coming weekend in San Diego then off to Hawaii for 10 days. This is the second time around for me and a lot more fun!

I will check in from time to time because I do enjoy helping people fix their boats. In the meantime, micadk needs to buy a IR gun and get some readings for you.

-John
 
Gee, thanks :smt101 I think :grin:

Second time is always better. I'm on #2 also. And I agree, much more fun!

Congrats and have a safe trip!
 
Ok. . .here is my two cents:

First, buy an IR gun; one with a laser (so you KNOW where it is pointing). Sears has them. (I paid $80 last month, but that model is no longer on the website. They have a more expensive model for $149).

Second: Shoot temperatures in the thermostat area: right where the thermostat and temperature probes are located. If you have a 160F thermostat, and nothing is over 160F. . . .you are not overheating. You may have some pressure, flow issues. . .but it doesn't affect water flow to the point that the engine needs more than the pumps are supplying.

Third: Shoot the risers. I would expect them to be cooler than the thermostat. My 160F thermostats result in a thermostat housing in the 165-170F range (both engines). Risers are in the 130-140 range. The risers should have the same temperatures. It is probably ok to have a difference of 10-20F between risers I think. I have two engines, on one engine the spread is 10F and the other the spread is 20F.

If your risers have a 50F spread, and they are getting over 190F. . .then you probably have a restriction (corrossion) in the manifold riser assemblies.


You can run these tests on Muffs. . .but running on muffs will only reveal GROSS problems. I mean, on shore the engines are (1) not under load (heat generation is minimal) and (2) water flow is low (a hose can only supply about 2.5 GPM, which I "think" is about a tenth of the engine water pump capacity.
 
OK will do on the IR gun. I will get some readings this weekend.
Like I have said, I do not believe it is an overheat problem, the gauge never went above 163. (if you can trust it) The Smartcraft and the analog are right there together, the analog is a little faster to get there, but they end up reading the same.
Playdate, good luck to you and have fun, I am on #3 myself. I never learn.
 
Note: on my engine (pre smartcraft), there are TWO temperature sensors. One is hooked to my gauge, and the other to the engine alarm.

I suspect (but do no know) that your two readings are coming from two seperate sensors. If BOTH show 163F, then you are fine (assuming your risers are reasonably close together in temperature). It sounds like you have a standard 160F thermostat installed, and your thermostat is CONTROLLING the water temperature. This gizmo deliberately bypassing water around the engine block so that it maintains the 160F-ish temperature. If you exceed your 160-ish, then that means your thermostat is sending ALL the water it can to the engine, and the engine is overheating to some degree.

And yes, after first starting your engine, it is cold. It takes a few minutes to build up heat in the engine.

Buy the IR gun to give yourself piece of mind, but I suspect your engine is fine.

All that said: manifolds and elbows are not long life items. On my boat, the previous owner stored the boat on a lift and flushed after every use. Total hours was low. At 9 years, the risers were somewhat corroded (had some life left . . .but not much). If your boat has been used for 4 seasons, you are probably still ok but this winter you probably want to pull the exhaust apart for an inspection.
 
Comsnark, yea I agree with you that I need an IR gun. Always an excuse to buy a new tool LOL.
The temperature at 160-163 is normal. As far as I can remember it has been this way, although never paid as close attention to it. If it seemed OK, I went boating. Usually I will scan the analog gauges, and have the Smartcraft on depth, or fuel monitoring duties.
I know there is water going through the exhaust, and I still believe that the engine is not running hotter than normal. I just noticed the change in water flow from one side to the other. That tells me I am beginning to have some sort of issue. So if I start diagnosing now it won't lead to further damages.
Some of those other threads were quite lengthy and some went through a lot of money before finding the problem.
I ran the boat on plane when I got to the lake for about 5 minutes, then shut it down and I could touch both risers and the tops of the manifolds. The starboard side seemed hotter to the touch.
I ran it again and checked the rubber exhaust hoses, which did not seem hot at all. So I did not worry with it over the rest of the weekend, but kept an eye on the temp gauge. With the weather we had, we did not go to far anyway.
If I can go for the rest of the season, which we probably won't use the boat too much, I can pull it all down this winter and see what I need to replace or fix.
Thanks a lot for your help.
 
I spent $417.00 for manifolds and risers, came with the mounting gaskets. A new t-stat $23.00. 4 hoses for $68.00. Outdrive water pump kit $50.00. Circulator pump on the front of the motor $90.00. 2 new belts $27.00.

Adds up to $675.00, which included the shipping) Just went thru the receipts.

Manifolds and risers (E-Bay, they are GLM and are coated on the inside) T-Stat (West Marine) Hoses (ebasicpower.com) Circulator pump (NAPA Sierra Marine) Belts (NAPA Sierra Marine)

Labor was my time, about 6 hours total.
 
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