1962 Evinrude 75hp Carb Float Level Setting

[kuts]

Part of the history: I have model 505298 that I got from my uncle in 2015. The carb only has low idle jet adjustment. The high speed jets are not adjustable. The old float lost it's coating and was loading up with fuel. Would run OK for about 1 day but then starts loosing prime and in general wont' start or idle correctly. I had made adjustments (don;t remember what I did in 2017) but then the exhaust by-pass started engaging which kills the motor when trying idle. Anyway I tried several coatings on two new floats and super-glue seems to be the best. Supper glue is lighter than airplane dope and does not get soft like airplane dope after soaking in gas for couple of hours. Before applying superglue I removed as much of the OEM coating as possible with methyethylekeytone (striper). However, the superglue coating ends puts the total weight of the float slightly more weight than the OEM float maybe 1 gram more.

So I installed the float even with the carb housing with the brass arm extended straight out from the hinge to the float. This put the top float about 9/32-inch below the top of the bowl. No problem priming the carb. but very hard to start, high gas smell when running, will not idle and quickly engages the exhaust bypas valve and kills the engine.

My service manual bulletin for the Starfliite does not list my moldel number even though it is supposed to be a bulletin for 1961 Starflite. It states to set the float level "flush" with the top of bowl. That cannot be right. Or is it? I would have to bend the brass arm on the float I think too much to make the float flush with the top of the bowl. The old float was not like that but I think the old float was adjusted by others before me. Howevern no indication that it was ever "flush" with the top of the bowl.

Does anyone have a better description of the proper float level? Any advise? Thanks in advance for any help on this.

 

[boobie]

When carb is turned upside down the top of the float should parallel with the carb body.

 

[F_R]

What exhaust bypass valve?

 

[racerone]

I want to know as well.------But perhaps you are confused by a hot water choke ????-----Is the thermostat installed and working ?

 

[Rook66]

Why are you putting super glue or anything else on new floats?

 

[oldboat1]

^^You may want to replace those floats again with new ones, using the replacements out of the box. They run $18-$20 so not cheap, but don't think coating them is a good choice -- should do fine for years. I'm not sure whether those floats can be installed upside down, but something worth checking.

 

[kuts]

When carb is turned upside down the top of the float should parallel with the carb body.

That is exactly they way I did it.

 

[oldboat1]

Check the diagram for float installation configuration (pictured with the carb right-side up): http://www.fiberglassics.com/library...service003.pdf

 

[kuts]

Check the diagram for float installation configuration (pictured with the carb right-side up): http://www.fiberglassics.com/library...service003.pdf

Thank you. I saw that on the secrete page just about the same time you replied. That is how I set it up. I might bend it down into the bowl just a tad to counter balance the new float being slightly more weight. It is great to have that link. Maybe the correct instructions will help as I keep going with this old motor.

I also neglected to mention that it backfired when I was testing. The backfire happens at the last stroke when it dies after the exhaust diverter valve engages.

I also adjusted the points at the same time I did the float. That's what I get for making multi adjustments at the same time. I am now wondering if I messed that up.

Another problem is that I did my rework in the fall of 2017 and just now getting back to testing what I did in 2017. I am getting more forgetful these days. I can't remember but I might have tweaked the timing belt one tooth. I just read the instructions for timing on the link that you sent over and they are not the same as the instructions that I have. The manual that I have says to set the throttle to SLOW before setting the timing. The instruction you sent over I don't see anything about that. In addition, the manual I have goes up to 1961 so not sure it works the same on 1962 models. My manual does not define SLOW. My throttle does not have a SLOW mark. Anyway I know that I must have the magneto in the correct position.

So this leads to the next question, "what is the correct magneto position for setting the timing?" If I had the correct magneto position it might help me figure out if I tweaked the timing belt incorrectly. Thanks for your patience with an old man working on an old boat.

 

[kuts]

^^You may want to replace those floats again with new ones, using the replacements out of the box. They run $18-$20 so not cheap, but don't think coating them is a good choice -- should do fine for years. I'm not sure whether those floats can be installed upside down, but something worth checking.

I am running E-10 fuel mixed 24:1 with marine 2 cycle oil. The new OEM float is cork laminated with lacquer. It is not new because nobody makes this float anymore. But it is never been used in the original OEM package. It is a rectangle about 2.5" x 1.25" x 3/4". Cannot flip it over. They do not make this float for E-10 fuel.

 

[jimmbo]

I also neglected to mention that it backfired when I was testing. The backfire happens at the last stroke when it dies after the exhaust diverter valve engages.

Exhaust Diverter Valve? Never heard that one before, or of it...

 

[kuts]

Why are you putting super glue or anything else on new floats?

Super Glue is Cyanoacrylate. Gasoline and/or ethanol cannot penetrate this material even pure ethanol. The OEM float is cork and is coated with lacquer to protect it from absorbing gasoline. The new float is an OEM cork float because nobody makes this float for use in E10 fuel.

E-10 fuel dissolves lacquer.

It starts out making the lacquer coating soft and then pieces of the lacquer de-laminate inside the bowl. Eventually the entire lacquer coating is gone.

The follwing I have researched and from much reading I have learned this: Once the lacquer coating is compromised the cork absorbs too much gas into the cork ...more than should be changing the buoyancy of the float. The bowl is only 1.75 inch deep and float action is only about 1 inch. So even if I make adjustments to compensate this affects the power range where the motor sputters in the mid range and has problems pulling skiers out of the water. Top end is OK because the float is not floating anymore. Gasoline breaks down the cork material making it more porous and that is why the manufacture used lacquer to start with back in the days before E-10.

 

[racerone]

What is this exhaust diverter valve??----Or the exhaust bypass you referred to in post #1 ??

 

[jimmbo]

It is time to start leaning on the Governments to Ban Alcohol in Gasoline

 

[kuts]

Exhaust Diverter Valve? Never heard that one before, or of it...

That's what I call it. It has a technical name. I forget what the real name is. There are 2 exhaust valves that divert the exhaust. One is a flow poppet type valve. The other is a thermostat valve (varathane sp?). Each of these valves cause the exhaust to divert down into the underwater part of the lower unit.

When the motor is running at idle all of the exhaust is blowing out into the air above the water line. This is to reduce back pressure and thus enhance a lower idle speed as well as aid with starting. Then when advancing to higher RPM the water flow increases in the cooling system causing the poppet valve to engage and that diverts "all" of the exhaust under water in the lower unit to lower the noise.

The thermostat (varathane) does the same thing except on over heating. If the motor overheats at idle (like when idleing slow running in a lot of water grass and the grass plugs up the intake on the water pump) the thermostat kicks engages the exhaust valve and pushes the exhaust out under water thereby increasing back pressure which kills the motor at idle speed so that you don't fry your piston rings.

 

[kuts]

I want to know as well.------But perhaps you are confused by a hot water choke ????-----Is the thermostat installed and working ?

You bring up a good point. Yes it works. I thought it was hooked. I might have missed this too. I did not check to see if it was hooked when I took the carb apart. You might be onto something. I will make sure it is hooked when i reassemble. Than you.

 

[kuts]

It is time to start leaning on the Governments to Ban Alcohol in Gasoline

Yes. I agree. It is a hoax. Everything about E-Fuel is a hoax and it is proof that environmental science has deep rooted ethical problems.

 

[kuts]

What is this exhaust diverter valve??----Or the exhaust bypass you referred to in post #1 ??

Sorry I did answer this in another reply please read through and you will see what it is.

 

[racerone]

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.

 

[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 vernatherm assembly below the distributor is what I am talking about. I can see no direct link from the hot water choke to that assembly. The hot water choke taps off of the block. There are two valves in the vernatherm assembly if I remember correctly. I have rebuilt that box and installed new valves and new spring and new central distribution section, new gaskets and new top section. I also replaced the vernatherm with a used one. The work I did on that did not seem to change anything. The new hoses were hard to find. The old plastic parts even though they were worn seemed to be OK.That assembly controls where the exhaust exits and when. I still have all the old stuff.

I have to say when I first got it from my Uncle it was trying to engage the vernatherm valves every now and then at idle but not enough to kill the motor. The first float I replaced in 2016 I just stuck it in with no adjustment. The brass arm was tilted up from the factory putting the float on an slight angle when turned upside down but I did not get analytical and measure it. It ran OK but I had the low speed jets adjusted to about 5/8 turn. At that time in 2016 I replaced the fuel pump diaphragm, the fuel lines, and installed a new OEM cork float with factory lacquer coating. It ran OK. Took it to the lake a few times and out on the river a few times and then it started sputtering in the mid range and not starting not holding prime, etc and the veratherm assembly was engaging at idle more and more as the performance dropped off. I put it away for the winter.

When I took the carb apart in the fall of 2017 the lacquer coating on the new OEM float was coming apart swelling and bulges in it pieces gone. That's why I replaced the float again. The float I have now is another same as the last one except I coated it with supper glue and adjusted the brass arm to make cork float even with body of the carb when turned upside down. Just like the drawing on the link but I was guessing based on what a river buddy of mine told me.

This week I did my testing run in the back yard. I could hear the vernatherm assembly "thump" and watch the exhaust divert to the lower unit and that added back pressure from the water in my water tank which kills the motor before I can make hardly any adjustments and ends with a back fire pop.