where's the tell tale? mid-section?

spacerust

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i took it apart and noticed that the tell tale spout is attached to another hose that goes no where. it's about 6 inches long. is it possible that this outboard does not have the tell tale? did any years come this way? when i bought this motor i was told that it was a 75 according to the serial provided. i never looked for it. no i don't know where the serial is? i am wondering if this outboard is a different year? any help?
 

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Re: no tell tale hose?

Re: no tell tale hose?

It makes it A LOT easier to help, it you were to reply to your original post(s) where you specified what motor we're discussing. Your reply will end up right at the top of the list.

Assuming your speaking of the 1975 Merc 150 inline 6 motor... it left the factory with a telltale.

Serial number is on the transom bracket in the front, just below the cowling. Its on the part that bolts to the boat, and just below the steering arm.

Can you take a pic of the hoses you described?
 

spacerust

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Re: no tell tale hose?

Re: no tell tale hose?

I remember seeing that number. i know it started 436. i always thought that the serial number of the motor i had was 413. i will take a picture of it tomorrow since it is already getting dark. i know i will be thinking of this all night.
 

spacerust

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where's the tell tale?

where's the tell tale?

is there any modification that can be done so that the tell tell is not a stream from above but from the mid-section? this is really confusing because i can't seem to determine where this hose should go. were there any models during the 70's that did not have the tell tale?
 

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Re: where's the tell tale? mid-section?

Nope...they all had telltale streams. It is quite possible that somebody disconnected it, re-routed it, or its simply plugged.

Email or post a pic of the tubing that is there if you can.
 

spacerust

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Re: where's the tell tale? mid-section?

here are some pics. i really am hoping you guys can shed some light on this? the guy told me that when flushing it is through the prop but when i run her in the water the tell tale would be there. i don't see how this could be.
 

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spacerust

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Re: where's the tell tale? mid-section?

i was doing a search on the net and i was reading about some Mercs that had a racing lower unit that has an exhaust ported thru the mid-section. it mentions about a red flywheel on top and thunderbolt ignition. i don't know how accurate this information is but this is pretty close to describing the outboard i have. the serial that i found is 4319959. could this help you in helping me?
 

AMD Rules

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Re: where's the tell tale? mid-section?

Yup... 1976 motor.

You have a telltale....in your hand. Its just not connected for some reason.

The wiring has been tampered with to, so let's assume there is a plug somewhere that you should be able to hook up to a fitting.

I'll dig up some pics that may help.

Can you take a peek up under the top cover, and look for a water fitting plug?

Also need a pic of the opposite side. There should be a fitting on the exhaust cover plate, near the bottom. You should see a brass elbow fitting there somewhere (see item #16).
 

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spacerust

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Re: where's the tell tale? mid-section?

here are some additional pics. i looked but i don't see anything that might have been plugged. but the hose is expanded at the end leading me to believe it was attached to something before. i talked to the guy i got it from and i don't really think he knew too much about it. on one of the pics there is a little boxed shaped resevoir that has an open hose connected to it as if it drains something in there and then goes into the lower part of the powerhead. before i changed the impeller i ran last weekend to evaulate and do a compression check. she didn't smoke, didn't get hot, actually it was real cool to the touch when i turned her off. don't know if this helps.
 

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AMD Rules

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Re: where's the tell tale? mid-section?

Based on the photos you provided, I would suggest that originally the telltale was connected to a right angle fitting on the water jacket cover between cylinder 3 and 4 (check that telltale tube length...I think its the correct length to reach). In its place the previous owner installed a temperature sender instead (see the wire there now) and opted not to have a telltale at all.

IF you wish to have a telltale, have a peek around the other side down below, and see if you have a plug on the exhuast cover. You might be able to connect it there with a right angle fitting. Pic attached is my '72 Merc.... where it connects using a platic 90? fitting. Either that, or you can remove the temperature sender if you're not going to use it with a guage.

Newer motors connect the telltale up top (better venting to avoid air pockets and hot spots on the upper cylinders), but yours does not have the boss fitting to do so. You'd have to drill it.



p.s. that tube up front is just a drain for the carbs, when they leak fuel.... supposed to be open ended like you mentioned.
 

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spacerust

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Re: where's the tell tale? mid-section?

so i should be okay then, right? i already left where i keep the boat so i will check to see if there is temp gauge. i know there is one for the water pressure. idling he said it runs about 5 psi while it is 20psi in the water. i am going to look into the options of a temp gauge(should it not have one) or adding the tell tale. which do you feel would be more reliable? And if temp gauge, what would a normal temp range be? i really appreciate all your info. thanks!
 

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Re: where's the tell tale? mid-section?

Sorry... my mistake. Thats probably a water pressure connection -not- a temperature sender.

You should be okay to run like that.... just be aware of what the pressure is 'normally' so that you can spot when something is wrong.

Happy boating.
 

Chris1956

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Re: where's the tell tale? mid-section?

Spacerust, You can remove the pressure sensor and install a brass or plastic tee. screw a nipple into one side of the tee and install the pressure tap in the other side of the tee. This will give you both the water perssure reading and a telltale.

Those were the instructions that came with my water pressure gauge that I installed on my '77 1500.
 

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Re: where's the tell tale? mid-section?

Good suggestion.... thanks Chris.
 

spacerust

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Re: where's the tell tale? mid-section?

that sounds like a great idea. a best of both worlds? and sound pretty easy too. what does the pressure sensor look like? could you point it out?
 

big_b16

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Re: where's the tell tale? mid-section?

Some pressure sensors are actually in the gauge on the dash. The T-fitting on the coolant discharge will allow water to flow through the straight path with a little bit going in the smaller "pressure" direction (t'd off port). The smaller diameter pressure hose will run back up to the gauge. The little amount of water in the pressure hose will press on the air in the pressure hose with varying intensity as the engine shaft (and thus the waterpump) rotates faster. The pressure gauge on the dash has a "dry/dry" diaphram (air on either side as it deflects...there are dry/wet and wet/wet) that will use the deflection to generate a pressure reading. Pressure is usually measured this way, so a mechanical event (diaphram stretching) can lead to an electrical response (electrode stretching...changing resistance) which can be converted into a pressure reading if calibrated correctly. If you get a jumpy or non steady pressure reading, then water has likely come in contact with the diaphram giving erroneous readings (remove hose and blow the water out). Good luck.
 
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