1962 Evinrude 75hp Carb Float Level Setting

[kuts]

We are still not sure what you refer to with the exhaust bypass or exhaust diverter.-----------This motor left the factory with a hot water choke on the carburetor.----There is a thermostat / vernatherm assembly below the distributor as well.

The thermostat vernatherm does not control motor temperature on this motor. According to the manual it controls the distribution of the exhaust. After rebuilding it I can see that the verathem assembly is indeed an exhaust distribution control system.

 

[oldboat1]

Well, from this old codger (amateur — a plea for tolerance), a t.stat controls/diverts hot water on any outboard in the sense that it contains the water in the powerhead until operating temp is reached, then opens to allow an influx of cooler water and an exodus of heated/unblended water. On motors with that hot water choke, the choke remains engaged until the water temp in the powerhead is optimum, as determined by the t.stat. At that point the t.stat opens, water in the powerhead cools, and choke pulls off. It’s an elegant system, imo, although I haven’t had to troubleshoot one any further than replacing a hose or two.

You do have the option of running the engine in the manual choke mode. It sounds to me like the choke may not be engaging properly, yielding lean running and the popping and stalling.

 

[jimmbo]

The thermostat vernatherm does not control motor temperature on this motor. According to the manual it controls the distribution of the exhaust. After rebuilding it I can see that the verathem assembly is indeed an exhaust distribution control system.

Exactly what manual are you getting your info from?

 

[racerone]

Wonderful entertainment !

 

[kuts]

Wonderful entertainment !

OK to many on here asking about this exhaust and I admit I don't know where I got it from.

 

[kuts]

Exactly what manual are you getting your info from?

The manual I have is called Evinrude Service Manual Fourth Addition. I admit I don’t know what I am talking about with the vernatherm and don't remember where I heard it. It has been 18 months since I last worked on this motor. My apology for the confusion. The thing I am trying to explain is the Automatic Exhaust Relief found in my manual Section 5-7. After reading it I have to retract what I said about the vernatherm but what I said is more or less what I think I am seeing when trying to run the motor.
Let’s back up….originally when the motor made the thump/clunk sound, back when I first got it in 2015, I thought it was trying to slip into gear at idle speed because the entire motor torqued to the side just slightly and the RPMs dropped like it was going into gear. But I have watched this go on now for a while and the prop does not turn and when it happens the exhaust pushes out more if not all below the water line for a split second and then the RMPs clime back up again gradually and exhaust increases through the upper air port above the water line which my manual calls out as part 77 in section 5 Exhaust Relief Boot. Then it would do again and again over and over but only after it was warmed up at idle speed and seldom did it kill the motor. Now this happens with more force torque sound (the thump clunk sound is louder) and it kills the motor.

I thought the vernatherm assembly was doing this but I rebuilt it and no changes ....still clunks and kills the motor but the motor is not running right at all since I replaced the float and adjusted the points.

 

[F_R]

I think your motor is lean sneezing and stalling. That is from running too lean (carb adjustment). If I am guessing wrong, so be it. But it absolutely is NOT related to the vernatherm / thermostat.

OK, I'm going to sit here and write a book (again) about how the thermostat works. That motor has a thermostat-controlled recirculating cooling system. The water pump sends water up one of two water tubes, to the powerhead. The wateer then circulates through the powerhead and absorbs heat. Then the water is sent through the two hoses at the thermostat box and presented to the vernatherm. If it is not warm enough, the vernatherm valve stays closed and high water pressure opens the pressure valve, which directs the water back down to the water pump by way of the second water tube. The water pump then sends it back to the powerhead for another pass-through and the water is presented to the vernatherm again---and the cycle continues. When the vernatherm says it is warm enough, it expands and opens the vernatherm valve and water is expelled back to the lake and the water pump picks up new lake water and the whole process repeats over and over again. Note that it is not an either-or thing. The vernatherm is constantly sampling the water and opening or closing as required to maintain proper engine temperature. At idle speed and cold water, it may never open at all.

Yes, some water always goes out the exhaust to keep the exhaust cool. That probably is what is confusing you. It does not change the exhaust flow in any way, except possibly change the tone a bit.

 

[F_R]

Did you resolve the belt timing? If it is advanced a tooth, it may cause lean-sneezing. Related is the carb/spark advance linkage. All this stuff has to be correct if you expect it to run right--and it will if everything is correct.

 

[kuts]

I think your motor is lean sneezing and stalling. That is from running too lean (carb adjustment). If I am guessing wrong, so be it. But it absolutely is NOT related to the vernatherm / thermostat.

OK, I'm going to sit here and write a book (again) about how the thermostat works. That motor has a thermostat-controlled recirculating cooling system. The water pump sends water up one of two water tubes, to the powerhead. The wateer then circulates through the powerhead and absorbs heat. Then the water is sent through the two hoses at the thermostat box and presented to the vernatherm. If it is not warm enough, the vernatherm valve stays closed and high water pressure opens the pressure valve, which directs the water back down to the water pump by way of the second water tube. The water pump then sends it back to the powerhead for another pass-through and the water is presented to the vernatherm again---and the cycle continues. When the vernatherm says it is warm enough, it expands and opens the vernatherm valve and water is expelled back to the lake and the water pump picks up new lake water and the whole process repeats over and over again. Note that it is not an either-or thing. The vernatherm is constantly sampling the water and opening or closing as required to maintain proper engine temperature. At idle speed and cold water, it may never open at all.

Yes, some water always goes out the exhaust to keep the exhaust cool. That probably is what is confusing you. It does not change the exhaust flow in any way, except possibly change the tone a bit.

Thank you. I think this will put me on track again. I was way off. I so often track myself the wrong direction thinking I have all the answers. I just read another thread on the cooling system and pretty much exactly what you just said. I also found a video of a evinrude motor running a little worse than mine but basically the same way mine is acting....same clunking noise see this video and they are saying the same thing you are lean sneezing. I never heard of that before. https://www.youtube.com/watch?v=Cl1gm5tUS2g

 

[kuts]

Did you resolve the belt timing? If it is advanced a tooth, it may cause lean-sneezing. Related is the carb/spark advance linkage. All this stuff has to be correct if you expect it to run right--and it will if everything is correct.

Yes I do think I have lean problem as I just posted a video of another motor running making the same clunking sound. No I did not resolve the timing. I need to know where the advance of the magneto pulley should be located when setting the timing or I could just move it one tooth and see how it works.

 

[F_R]

Yep, that guy has a classic case of lean sneezing. I see a few things wrong with his motor, but it is a different motor than what you have.

BTW, I should have said retarded instead of advanced. Whatever.

OK, does your motor still have the micro-switch on the distributor bracket? If so, the switch button is the timing mark. Mark on pulley aligns with button, mark on flywheel aligns with marks on recoil starter and cylinder block.

Oops----shoulda asked, is your motor battery/coil ignition or magneto ignition? Different marks.

 

[kuts]

Did you resolve the belt timing? If it is advanced a tooth, it may cause lean-sneezing. Related is the carb/spark advance linkage. All this stuff has to be correct if you expect it to run right--and it will if everything is correct.

Thanks for your help. About the carb spark advance linkage; I did have that correct at one time and it was a pain to get it like the book says due to the instructions are confusing. I did finally find the diamond shaped (triangle) lug to set the arm parallel to, 0.20 gap on the stop, mark on the brass cam lined up with butterfly correct, and finally found the set screw.....inside the other set screw.....to adjust the cam. If I re-time I think all that needs another adjustment right?

 

[F_R]

Again: Battery/coil ignition or magneto? Battery ign has distributor cap on top, magneto has distributor pointing downward. Different timing procedure.

 

[kuts]

Yep, that guy has a classic case of lean sneezing. I see a few things wrong with his motor, but it is a different motor than what you have.

BTW, I should have said retarded instead of advanced. Whatever.

OK, does your motor still have the micro-switch on the distributor bracket? If so, the switch button is the timing mark. Mark on pulley aligns with button, mark on flywheel aligns with marks on recoil starter and cylinder block.

Oops----shoulda asked, is your motor battery/coil ignition or magneto ignition? Different marks.

My motor does not have a coil. My starter is on the other side of the motor but there is a mark on the plate where, if this was a Johnson or other model, the starter would be located. The fly wheel mark is lined up.

It has a small switch I think they call it the safety switch. There is a lobe under the magneto pulley that contacts the switch with a mark just above the center of the lobe.This lobe with mark on it varies in location pending the throttle setting.

 

[kuts]

Again: Battery/coil ignition or magneto? Battery ign has distributor cap on top, magneto has distributor pointing downward. Different timing procedure.

Distributor pointing down.

 

[racerone]

It sure does have a coil.-----You can not see it.----It is inside the magneto !---That one empty ( starter ) location you speak of might be for an optional belt driven generator.-----Johnson / Evinrude /.Gale V-4 motors of that era all have the starter in the same location

 

[F_R]

Distributor pointing down.

Whew, glad we got that settled. Never mind the mark on the throttle cam, it is the mark on the pulley that needs to align with the safety switch plunger. Also align the flywheel mark. Don't make it complicated.

 

[kuts]

It sure does have a coil.-----You can not see it.----It is inside the magneto !---That one empty ( starter ) location you speak of might be for an optional belt driven generator.-----Johnson / Evinrude /.Gale V-4 motors of that era all have the starter in the same location

I did not know that. Thanks for the information.

I have seen a video of a Johnson same motor but yes a different year with the starter on the left looking at the motor from the rear. My starter is on the right front looking from the rear of the motor and the starter mounting plate has identical mounting holes on the left front but nothing there.

 

[racerone]

No---- that would be an optional belt driven generator on the early V-4 like yours.----Yours obviously does not have that generator.--------Evinrude and Johnson are the same except for paint in most years.

 

[F_R]

What racerone said, that is for the optional accessory generator kit. The generator does sort of look like a starter. They never did put the starter on the port (left) side.