Thermostat vs. gate valve

[caribbean20]

I've been running a thermostat on my jet boat motors for the last 14 years. I had some work done by a socal jet shop this winter (roller cam, rockers, intake, etc.) and the shop plumbed my motor for an open system without using the thermostat, without telling me (they used the same thermostat housing, only no thermostat inside). Boat ran fine but got no water temperature (they didn't bother to install a gate valve).
Since no water temperature, I had a different shop in Boulder City (I keep the boat in Vegas) install a thermostat. This shop does not normally work on jets and they likely did not recognize the fact that it was not plumbed for a thermostat, as did I. Long story a bit shorter, after hauling the beast all the way up to Shasta, I burned a hole in my starboard side exhaust hose. I inspected the situation, removed the thermostat and installed a new hose. Same result. Inspected again, checked water lines, exhaust risers (EMI Thunder) and water was coming out of the exhaust on both sides in a similar quantity, at idle speed. After running the boat for about 5 minutes, the starboard side hose was getting a lot more hot than port, ready to burn yet another hole. I am stumped.
I took the boat to another socal jet shop (a shop everyone on this board just raves about) to fix this problem and several others and this guy tells me they never see a jet plumbed for a thermostat. They always use a gate valve.
Questions:
1) Any guesses as to why I keep burning a hole in the hose? There must be an obstruction but it sure looks like water is coming out of this exhaust just fine, at least at idle.
2) Anyone else running a thermostat? I would prefer to keep this, it worked fine for many years, but shop #3 sure seemed puzzled at the notion of using a thermostat.
My equipment is pretty standard, BBC (Gen VI with GM Marine aluminum heads), Berk pump.

[Oldsquirt]

When you say you were running a t-stat, can we assume you had the whole t-stat kit with bypass hoses and 4-port housing with stat and poppet valve inside?
Since you burned the same exhaust hose both with and without t-stat, I would be looking more closely at the coolant hoses themselves for restriction, specifically the one dumping into that side's exhaust.
A picture of the plumbing, both into and out of the motor, would be helpful.

[bp]

i've never run a thermostat on a jet in 28 years, logs/hose or headers.
so.. you didn't say how hot did the water temp was, coming out of the engine? could you be running the engine a little leaner with the changes you made, and the exhaust gas temp a little hotter? are you running an oil cooler?
as craig said, more info is needed on the way you currently have it plumbed.

[olbiezer]

my daytona has a thermostat ......runs fine with it.......first boat out of 5 jets that i have owned with one...... :) :rollside:

[centerhill condor]

old squirt is on to something with the hose...the condor came without a 'stat being from texas and all..here in TN she always ran too cold for me anyway.. Installed a pressure regulator and a 160 stat with two 1/4" holes drilled on opposing sides of the spring to prevent pipe burn through..fixed everything for me...proper temp year 'round.

[caribbean20]

OldSquirt, my response:
When you say you were running a t-stat, can we assume you had the whole t-stat kit with bypass hoses and 4-port housing with stat and poppet valve inside?
Yes, I did to all of the above and it worked fine for many years, and also on this motor before the recent mods. When shop #1 made the changes, they kept the 4-port housing in place and just plugged 2 ports and removed the innards (I suspect). Motor ran fine for 3 outings this year before the ill-fated Shasta trip.
Since you burned the same exhaust hose both with and without t-stat, I would be looking more closely at the coolant hoses themselves for restriction, specifically the one dumping into that side's exhaust.
Exactly what I thought and I inspected this line thoroughly, both blowing into the line to ensure no restrictions and physically observing water coming out of the t-stat housing, the other end of the hose going to the exhaust, and out of the exhaust tip itself with everything hooked up, except for the rubber hose to the transom.
I even exchanged exhaust risers from port to starboard to make sure there was no restriction in the riser. Looked like the same amount of water coming out of both risers, with rubber hoses (exhaust) removed, at least at idle.
I have a picture of the plumbing before and after, but need help posting.
bp
so.. you didn't say how hot did the water temp was, coming out of the engine? could you be running the engine a little leaner with the changes you made, and the exhaust gas temp a little hotter? are you running an oil cooler?
yes, the motor could be running a bit leaner since I did not change jets on the carb with the new roller cam (580 lift, 240 @ 50 duration intake side), and single plane intake (Vic Jr.). Also, I do not run an oil cooer. Lean condition is my first thought.
I have the boat at TPR. We'll see what he has to say.

[Rexone]

Do a search on thermostat. There are lots of threads on this subject.
We've sold litterally thousands of these and they work well.

[Glenn]

Never decrease water volume to engine. Thats what ford + berkekely said. I gots ford460scj 550hp creat mot. + nos 150hp 11.5:1 comp. Run water pressure ragulator (20-40psi) on main feed line(if running stock not needed) with adjustble thermastate bypass ball valve. Runs at 160deg all the time. Gots to get that heat out exsp. hi comp engine. Rex offers one for bbc but not bbf. You make your own up with 5/8 adjustable ball valve to bypass t-state hausing. Adjust for 160 deg. at planning speed. I read 160deg. wot to 170 at idle with inline oil cooler.

[GottaJet]

Do a search on thermostat. There are lots of threads on this subject.
We've sold litterally thousands of these and they work well.
Anything available for BBF yet ??

[BigBlockBaja]

Anything available for BBF yet ??
with a little bit of grinding, they will work on a BBF. Im running one now for 2 years no problems. Motor runs 175 all day.

[HammerDown]

Do a search on thermostat. There are lots of threads on this subject.
We've sold litterally thousands of these and they work well.
You can say that again.

[Nubbs]

You can say that again.
I agree

[Rexone]

You can say that again.
Do a search on thermostat. There are lots of threads on this subject.
We've sold litterally thousands of these and they work well.

[Rexone]

Anything available for BBF yet ??
No not yet. I keep kicking it around but am having trouble justifying the mold cost for the probably few Ford units we'd sell in this day and age. Should have done it 20 years ago when there were lots of new Fords being built but never did. So that one has become a tough call.