Can bigger tell-tale cause overheating

[Cricket Too]

I have swapped out my stock tell-tales on both of my 99 Johnson 200's with a fitting that is made for a garden hose. It is a quick disconnect for putting different things on the end of the hose. I use this for flushing out my motors when I come back into my slip, all I have to do is stick the hose directly onto the quick disconnect and start flushing, instead of having to unscrew the stock one then screw in an attachment and then screw the hose on, it makes it alot easier and faster.<br /><br />I have noticed though that on my water pressure gauges my pressure has gone down a bit at both idle and WOT. I put one of the stock tell-tales back in and the pressure came back up on that motor. I'm figuring this is just because the hole on the stock is alot smaller than on the quick disconnect so there is not as much back pressure, when I put my finger over the end of the quick disconnect the pressure comes back also.<br /><br />My question is, will this cause the motors to run any hotter. I have been running them like this for about 2 months with no problems, ie. overheating, but even if it is not overheating I do not want any extra heat to cause wear over time. The water coming out of the tell-tales when running is always cold to luke warm like on the stock ones, so it doesn't feel like they are running hot. I just want to know if the less backpressure would cause not enough water to stay in the powerhead and possilbly not cool as well. Thanks. Mike.

 

[Spidybot]

Re: Can bigger tell-tale cause overheating

Your theory is correct. The cooling water flows into all channels and cavities of the water jacket and circulates according to the design of this and the pressure produced by the impeller.<br /><br />If you'd asked me before you tested, I'd have guessed a severe change in cooling capacity. As is it, you seem to get away with it.<br /><br />You could fit a valve to the tell hose so you can decide the size and backpressure when running it, and open it full when flushing. Or stop flushing it via the tell and use muffs instead.

 

[Ross J]

Re: Can bigger tell-tale cause overheating

Keep the new tell tail fitting, just adjust it - thus -<br />Remove the new fitting and install a washer behind it that permits just the same amount of water to leave as it did when the factory installed one did. Then re-install your new fitting. That should allow you to use the hose connection but still keep the water pressure up when the motor is in use. It's also very cheap to do!<br />(I learn't this one with my washing machine at home with a very high water pressure) <br />Ross

 

[Spidybot]

Re: Can bigger tell-tale cause overheating

Yeah - and if you use a manual valve instead you can turn it full open to get max flow when you flush.

 

[Cricket Too]

Re: Can bigger tell-tale cause overheating

UU and Ross J....Thanks for the input, both good ideas. I think I will give the valve idea a try so I can then open it up all the way when flushing, because I really can't flush using muffs since the boat is in a slip and always in the water, I'd have to make a hell of alot of noise and run them fully tilted up. I wish OMC, or I guess Bombardier now, would change the design of the flushing system so as not to use the tell-tale. I have seen Yamaha's system and it uses a separate hose facing inboard, that's only purpose is to flush the motor, it has a spinning hose attachment on the end just like a regular hose and the tell-tale is completely separate. I can't imagine how many guys have either dropped the tell-tale spigget into the water or stripped the threads out on the fitting. I guess it's better than not being able to flush out at all, which is what I used to do for years, never had any problems but it always pissed me off not to flush it out. Thanks again. Mike.

 

[Cricket Too]

Re: Can bigger tell-tale cause overheating

Does anyone out there know if the tell-tale on this particular motor actually has any effect on cooling. Am I worrying about this for nothing? Thanks. Mike.

 

[Cricket Too]

Re: Can bigger tell-tale cause overheating

Bump^

 

[ob]

Re: Can bigger tell-tale cause overheating

mmcpeck,All seems well with your quick disconnect idea since it has been put to the water test for some time.However ,there is still one unknown,and that is engine temp.Bare in mind that the overheat sensors are set to initiate at temps a good bit above what the normal running temp is.For instance,If your engine temps were running 145 before the change and are now running 160 you won't notice much difference in feel check and the overheat sensors won't be at the brink of initiating.We know at least that something has occured in your cooling system since the water pressure has decreased.Now , the million dollar question is has it decreased enough to effect the heat transfer squeeze of the cooling system or created any cavity hot spots that are not in the water flow of the overheat sensors.<br />Probably not.But ,the possibility exists,and as your waterpump gains more wear ,the pressure will drop even lower.<br /><br />Now the big question is,do you have more peace of mind operating the engine as is,or swapping fittings to flush.<br /><br />You could also make up a disconnect fitting that snapped onto what you have now, rigged with an orifice that was the same size as the original.Then just snap it off,and the hose on,when flushing.Use your water pressure as the baseline test.Good luck.

 

[Dhadley]

Re: Can bigger tell-tale cause overheating

Personally I would hesitate to lose enough water to drop pressure -- at all. I would be very concerned about keeping the block full -- and that looper block has a huge water cavity. Besides the obvious overheating issues I would not want the water cooled reg/rec to overheat. Not only could it cook an expensive part, it could possibly catch the wiring on fire if it were to short out.<br /><br />We dont want that.

 

[Cricket Too]

Re: Can bigger tell-tale cause overheating

Thanks alot guys, I really appreciate your input and expertise. I think I will figure out a way to have higher pressure with the quick release, probably install a valve in between like UU suggested. Thanks again. It's good to know I can get advice I can count on. Mike.

 

[backdraft]

Re: Can bigger tell-tale cause overheating

mmcpeck, If you have a water pump that is losing efficiency at all, at idle speeds and a hot engine, you may find a lack of water in the upper parts of the block. I have taken out plugs and thermostats while an engine was running and found the water level to drop in the upper castings while trying to track down a plugged cooling system. Extended trolling with this condition is not good. I would junk the flushing units and go back to the tried and true. Either that or do without the tell tales at all and rely on BMC or another good quality gauge.nevjb

 

[seahorse5]

Re: Can bigger tell-tale cause overheating

Why not buy the factory hose quick disconnect for flushing? It has a spring loaded valve in it and a "pee hole". For a few bucks it eliminates the problems that you are worried about.