Cooling of an evinrude 9.9

[phralh]

Just bought a used 1975 evinrude 9.9. Took it for a few testrides this weekend before winterizing. Ran great but I'm a little worried about the waterflow.. This is the older model with the mixed exhaust/water outlet. Also have a evinrude 6hp, and when compared there's more visible water passing through the 6hp. The 9.9 is getting hotter than I'm used to but I have no problem holding my hand on the block. Does anyone have experience of both these engines and can calm me? The 9.9 recently got the impeller changed I'm told.

Thanks
//Fredrik

 

[AlanR]

Re: Cooling of an evinrude 9.9

Id run it on the muffs and visably see that water is coming out of the exhaust... I have a 1980 Johnson 9.9 and I kno i have a pee hole on the side and I belive you do to.... How long ago was the impeler changed? Does it pump watter at high speeds?

 

[phralh]

Re: Cooling of an evinrude 9.9

The early models didn't have the peehole on the side. Check the picture!

Impeller changed recently, and I see about the same amount of water regarless if it idling or at wot.

 

[AlanR]

Re: Cooling of an evinrude 9.9

Ok Should me up good. I dont normaly work on small engines under 50. Anyways Did you run it on muffs and see how much water acctuly came out with the exhaust>?

 

[phralh]

Re: Cooling of an evinrude 9.9

Hahaha, did i?
Haven't checked water through exhaust, got to get me a pair of watermuffs first.. Will try this next spring before I put it back on the boat.

 

[OBJ]

Re: Cooling of an evinrude 9.9

The pee hole didn't show up on 9.9/15's till 77'. But you should have some misty spray, mostly when the engine is in the water, coming from the exhaust relief port. This would increase some once the t-stat opens.

Whan at idle, you should be able to place your fingers on the flat area on top of the block just forward of the head for several seconds. This "touch test" is a good indication that the engine is running around 143*....normal temp. If you can't touch the area at all, the engine is overheating. If the area dosen't heat up at all, check the t-stat....may have failed open.

 

[Boatist]

Re: Cooling of an evinrude 9.9

I have a 1975 15 HP which is the same motor with a different carb. It does not have a Pee Hole. Running on the water will get a little spray out the the exhaust relief hole on the back in the above picture when the thermostat is open. If you run on muffs will get very little spray water out the top exhaust relief hole. Without exhaust back pressure all the water goes out the bottom. Will get water out the above the cavation plate when the thermostat is open. On my unit after the motor warms up can hold finger on the top of the block for about 4 seconds.

Your motor and mine have the old style heads that caused a lot of plug fouling on older engines.

 

[phralh]

Re: Cooling of an evinrude 9.9

Thanks, that calmed me down a little. Since theres no good way telling if the cooling works while at running at wot, what about the possibility to put a temperaturemeter (sure there is a better word for this, but hey - I'm swedish!) on it? I'm talking about a temporary one, I'm talking installing one? Guage would of course need a powersource, but I'm running my fishfinder of a battery, so why not use that? Would a standard 104-248 sender/transmitter and guage intended for a cars coolingsystem work? Then convert and mount it somewhere on the block?

//Fredrik

 

[gss036]

Re: Cooling of an evinrude 9.9

http://www.wisnersinc.com/Fishing Info/Johnson 9.9_15.htm
This will make for interesting reading for you. It explains a lot of details. I had a 1975-76 9.9hp, but gave it to my son-in-law.

 

[OBJ]

Re: Cooling of an evinrude 9.9

At WOT, these engine will run around 150*F....if the impeller is good and t-stat is operating normally.

If your t-stat is good (have you checked it?) and the impeller is good, you should be getting normal temps at idle and WOT. Water leaving the engine will leave through the exhaust (as has been posted) and it's hard to determine water flow. The only thing you have to rely on is the misty spray from the exhaust relief port. I have noticed on occasion that if the t-stat is stuck open, and the engine is in the water, you will get a fairly heavy mist from the relief port at idle.

You can check the temp using temp sticks. These are like a crayon that melt at a given temp. The service manuals for these engines recommend a 143* and 163* stick for checking temps. All you really need is the 163. You make a mark with the stick on that flat place on the block. If the engine temp gets above 163* at WOT, the mark will liquify. If it stays solid, should be OK.

But I have to say that from your post's, I'm not real sure you have an overheat problem. If you can lay your fingers on the flat place on the block at idle rpms and hold them there without moving them, I would think your engine is running cold.

 

[phralh]

Re: Cooling of an evinrude 9.9

From reading the replies I've got I'm sure it's just fine. I'm just making sure what I can do to notice a malfunction in the future.. I'm checking the exhaustport constantly on all the engines I've had.. And everyone of em have been easier to determine if it's cooling allright. I'm new to this motor, but within time I'll probably get a feeling for it.

gss036 - that is a good link, that page was final when deciding whether to get a 9.9 or not in the first place!!

Thanks for all replies!
//Fredrik