1962 Evinrude 75hp Carb Float Level Setting

[F_R]

Agreed, fuel pump -OR- an air leak anywhere between the fuel pump and the level of the fuel in the tank. Fuel pump valves in that motor are very reliable unless dirt gets under one of them

 

[kuts]

Thanks for the tips on the fuel.

Maybe this next part should be re-posted as a new topic.....sort of getting away from the fuel/float.

I disconnected the positive wire off the starter and had my wife turn the key to start while I tested voltage between the positive and negative lugs on the power-head. I got 12.6 V the same as the battery right now. So the solenoid works.

The starter is likely the problem. I looked it over and with a small mirror under the starter where the starter has a drain hole or vent or oil port (it has a small hole in the bottom of the starter). This is the location where the fuel was spraying out of the drain hose before I fixed it. The drain hose is right below the starter. The fuel was spraying upward right into that hole. So I removed the starter and opened up the bottom to look at the brushes (the brushes are at the very bottom) and the part of the armature that that connects the brushes is loaded with cooked on oil as well as the brushes are loaded. The entire cavity is full of thick dried up grease or oil or both....there is a lot of it.

Overall the starter guts look good OK. The bronze bushings allow no noticeable play...nice snug fit to the race top and bottom of the starter. The part of the wires I can see (without cooked on oil) look OK (they don't look overheated). The gear teeth are in great shape. The only thing that I could complain about is the pinion and screw shaft seem a little stiff needing cleaned up and greased but the pinion still operates just fine.

A couple of questions on the starter.:

What would be the best thing to clean all the cooked on oil but not so strong solvent to damage the varnish on the wires or the insulation between the contact plates? Is the varnish lacquer?

Does anyone know how many ohms the coil is supposed test out at and the how many ohms for the armature? Where might I find that data? I would like to check before putting it back together. There are still a few out there for replacement but they are a little pricey.

 

[kuts]

FYI for the starter I ended up using mineral spirits to clean the oil off and electronic spray cleaner and then Brasso to get all the metal on the computator? and brushes shiny and smooth. I found out that the ohm readings on this starter are going to be small due to the gauge of the wire and minimal windings. I had 0.6 ohms on the armature coil plate to plate ( a couple plates were 0.5 ohms) and 0.7 ohms for the plates at 180 degrees. I had 24 Mega Ohms from the each plate to the shaft. I had 0.9 ohm on the outer field coil. Those readings are fair. The bottom thrust washer is badly worn but should last 100 more starts. I will replace it on the next order of parts. The starter works good this run with no disengaging and spins the motor as good as it has ever spun.

 

[kuts]

Agreed, fuel pump -OR- an air leak anywhere between the fuel pump and the level of the fuel in the tank. Fuel pump valves in that motor are very reliable unless dirt gets under one of them

I got it running. I put the fuel tank up on ladders with walk board about 2ft above the engine. Idle is a a tad rough but it was like that before. I can say it is a little smoother (steady) than before. The low speed jets I ended up at about 1.2 turns.

After I got everything adjusted and running smooth and steady for about 45 minutes I lowered the fuel tank back down in the boat and about 40 seconds later it starting revving up and down getting ready to lean sneeze so I shut it off before it stalled.

The fuel tank is brand new and so is the fuel supply line and primer. The fuel lines on the motor I replaced recently with ethanol resistant fuel lines. So I am pretty confident on the fuel supply system.

I am suspecting the fuel pump needs rebuilt.

 

[kuts]

Looking for some assurance from members higher ranking than me to confirm my opinion. Please read.

I have found the problem or at least what I think caused the majority of my motor running lean.

The output check valve in the fuel pump is broke.

There are two check valves that oppose each other. One is for the input and the other for the output. These are small nylon body and disc with a metal spring that actuates the nylon disc. The the body of the check valve has 4 stops that limit how far the valve can open. What I found is that the disc was pushed past 2 of the stops on one side of the valve and thus it was stuck open and no way the spring can push the disc back in place once on an angel in a bind. I popped the disc back in place with a flat head screw driver (took a fair amount of force) and can see the disc is warped and will not seal. However, pushing back to open on the disc almost hard enough to break it I cannot make the disc jump past the stops. Whatever pushed the disc past the stops was very powerful. The diaphragm is not ripped but it has an imprint of the check valve body in the diaphragm which in my "opinion" means the diaphragm bottomed out with significant force.

My opinion is that when I screwed with the timing and then tested resulting in backfire or perhaps the very hard thump of lean sneezing ( or combination of both) is what damaged the check valve. I will assume my new diaphragm is also damaged (over stretched). New parts on the way.

Any thoughts on this?

 

[kuts]

Agreed, fuel pump -OR- an air leak anywhere between the fuel pump and the level of the fuel in the tank. Fuel pump valves in that motor are very reliable unless dirt gets under one of them

Thanks. I installed a new OEM fuel pump. I had some other minor problems (thermostat housing was cracked) but it is running correctly now. I also missed the service manual instructions on adjusting the high speed center venturi tubes so took the carb apart and adjusted to center as best I could maybe +/- 0.005" using a home-made jig. I had a spare thermostat housing so that was easy to fix. I also installed a new condenser just for assurance.

The low speed jets seem to work best at about 7/8 turn after getting the new fuel pump with the engine cover off and just 1/16 more turn to lean with the engine cover on.

It was still running a tad rough at very low idle so I went back to 24:1 fuel mix and presto------it idles better than ever. I think it actually has better response on acceleration too but that just in the yard tank. I will have it on the water this weekend but I do not expect any problems. Have a great weekend hopefully you will be out on the water. Cheers!

 

[jimmbo]

If it runs better at 24:1 vs 50:1. that can be an indicator of a leaky upper crankshaft seal. The extra oil helps establish a seal. Even though the Oil spec in 62 was 24:1, the mechanicals of the engine did not change(exception being Tin Plating of the Piston Skirts in 63) in 64 when the Oil spec was changed to 50:1.

 

[kuts]

If it runs better at 24:1 vs 50:1. that can be an indicator of a leaky upper crankshaft seal. The extra oil helps establish a seal. Even though the Oil spec in 62 was 24:1, the mechanicals of the engine did not change(exception being Tin Plating of the Piston Skirts in 63) in 64 when the Oil spec was changed to 50:1.

Hmm. Would that mean that the crankcase pressure is potentially not correct?

 

[kuts]

If it runs better at 24:1 vs 50:1. that can be an indicator of a leaky upper crankshaft seal. The extra oil helps establish a seal. Even though the Oil spec in 62 was 24:1, the mechanicals of the engine did not change(exception being Tin Plating of the Piston Skirts in 63) in 64 when the Oil spec was changed to 50:1.

What about the lower crankshaft seal?

 

[racerone]

The lower crank seal is a carbon " mechanical " seal.--Very durable but fragile.-------Easy to replace with powerhead off-

 

[kuts]

The lower crank seal is a carbon " mechanical " seal.--Very durable but fragile.-------Easy to replace with powerhead off-

Thanks. The top crankshaft bearing seal looking at the drawings looks like maybe 1 O ring? I have flywheel pullers. Is flywheel puller the only major tool needed? Will the top bearing remain in place during top seal replacement? Or will I need to remove the bearing head assembly and replace that O ring too?

 

[racerone]

Looks like an O-ring to you.-----But it is a conventional oil seal !!-----And why are you suspecting that these seals need to bereplaced ???

 

[kuts]

Looks like an O-ring to you.-----But it is a conventional oil seal !!-----And why are you suspecting that these seals need to bereplaced ???

jimbo said that I might have indicator of leaky upper crankshaft seal. See above post May 22nd, 2019, 10:54 PM.

Since it is an oil seal type sounds like I would need to remove the bearing head and de-press and re-press the seal? Would the bearing also need to be de-pressed and re-pressed......maybe a new replacement bearing?

 

[racerone]

Do you see an oily mess around the top oil seal , yes or no ?--------Perhaps it was posted but what are the compression numbers on this motor ?-------I am not sure you have a " seal problem " on this motor !!!-----The bearing would come out with the housing if you did decide to jump in to replace the seal.-----The inner race for the bearing is the crankshaft.----Doubt you will replace that.----I believe you are starting to do too much guessing on your motor.-----Perhaps it is time to look at a real manual.

 

[kuts]

Do you see an oily mess around the top oil seal , yes or no ?--------Perhaps it was posted but what are the compression numbers on this motor ?-------I am not sure you have a " seal problem " on this motor !!!-----The bearing would come out with the housing if you did decide to jump in to replace the seal.-----The inner race for the bearing is the crankshaft.----Doubt you will replace that.----I believe you are starting to do too much guessing on your motor.-----Perhaps it is time to look at a real manual.

No.

First of all the reason why I decided to go back to 24:1 mix is because I suspect that the rings and cylinders are very worn (my uncle bought the boat new in 62 and he used the boat a lot). FYI The hull is a 62 Duracraft 15.5 ft closed bow. I had what I call a hunch that more oil might make cylinder compression just slightly better. The rough idle problem was not that bad so I was thinking that maybe more oil in the fuel would even out compression just a little and help to smooth the idle.

OK so I looked at the crank top seal area and it is clean and dry as a bone with no signs of leaking. I did not do a compression check yet but I am pretty sure compression is not so good since it seems pretty easy to turn over with the rope. I have a compression tester (brand new in the box that my father in law left to me) but I do not know exactly how to use it. Would compression testing be done with oil in the cylinder ? I guess I need the water pump in the water tank and crank the starter over? I just don't have a clue where to start on that.

 

[racerone]

There you go.----No problem with the upper seal then.------Remove the 4 bypass covers.----Inspect pistons and rings.-----Might need 4 cheap gaskets.

 

[kuts]

There you go.----No problem with the upper seal then.------Remove the 4 bypass covers.----Inspect pistons and rings.-----Might need 4 cheap gaskets.

I agree this inspection is needed. I did not find a boat ramp this weekend due to flooding in our area. I want to test run it on the water before removing the bypass covers. It might be a few weeks before the boat ramps are open.

racerone I want to thank you for helping me get on the right track back when I was talking about the thermostat bypass thing. However, reading back through my posts April 15th at 11:58pm I made a mistake in symptoms description. Back before I "thought" that I had a float or back fire problems the engine running at idle would make a very loud "click" sound and then lean sneeze. Back on April 15th I was calling it a "thump" sound but the word "click" is a better description and it was very loud. Back then I was thinking that click sound was the check valve in the thermostat assembly. Maybe it was the check valve in the fuel pump? I still don't know what made that sound or why.

 

[kuts]

There you go.----No problem with the upper seal then.------Remove the 4 bypass covers.----Inspect pistons and rings.-----Might need 4 cheap gaskets.

I did not open the bypass covers yet.

I tested on the river today for about 40 minutes. 36 mph top end about the same as before. It runs much better than before. Acceleration from idle is fantastic and would certainly yank a couple skiers up quick. From crawling idle I opened it all the way up as fast as I could push the throttle and no hesitation at all very solid and fast acceleration. It was never like that even back in 1980s when my Uncle used to pull us skiing and he used 24:1 mix. I was not expecting that. It runs slightly better top end when the engine door closed (maybe 1/4 mph) but idles better with engine door open. I have the idle set too slow (just wanted to see how slow I can idle). It will crawl real slow but after about 2 minutes it starts loading up. I have room to take the idle up about 25 rpm and still be at no wake so I think it will be OK after I adjust that.

Shut it off and started right back up. I had it set on automatic choke the whole time.

It still sputters in the mid range but only when cruising and de-acceleration at about half throttle (not during acceleration). At that point it vibrates a lot from about 2200 to maybe 2600 rpm. Maybe a little worse than before maybe not it is hard to tell. At one time the mid range was much smoother noting that the mid range has always been a little rough. I suspect that is the point where the throttle cam changes. Not sure but might still need more magneto sync work.

I am questioning how I adjusted the arm coming out of the magneto has an adjustable joint (two bolts) then another joint elongated slot with a spring. I can make the adjustable arm meet the criteria per instruction manual with the spring joint in several different tensions. The way I did it this time was set the arm with as much tension on the spring as I could. Not sure I did that right but don't see anything in the manual about the spring tension.

 

[kuts]

There you go.----No problem with the upper seal then.------Remove the 4 bypass covers.----Inspect pistons and rings.-----Might need 4 cheap gaskets.

Thanks racerone. I will keep in mind to check the piston and rings. For now it is running better than ever before. I am thinking to leave it alone at this time because it is running so well. I must have fumbled the carb to magneto sync last time I tested for which I had too much advance to the magneto. I readjusted and now the midrange cruising and de-acceleration is smooth running. I had it on the lake yesterday with passengers all day and had no problems. Did some fishing using the motor to troll , a lot of no-wake speed use, got up to full speed a few times......all with no problem. I am on my third tank a fuel running e-10 with 24-1 mix and everything works. My uncle will hopefully get to go with me later this summer or fall when his knee replacement heals. I think the problem in a nut shell was a combination fuel supply issues.

FYI
This post started back with my question about the float level. I coated the cork float with supper-glue and it works at the factory carb float level adjustment. The float is just on gram more weight with the super-glue coating. Now after buying 3 OEM cork floats I found that they vary +/- 2 grams from the factory so one gram more is not enough to change anything. Before applying the supper-glue I purchased a new 1980's OEM float in the fall of 2017 and removed the OEM Lacquer coating using spray can paint stripper. Then applied supper-glue to each side (6 sides) one side at a time letting it dry for about 2 hours before coating the next side. Let cure for 2 days. Once cured I submerged the float in E-10 fuel for 2 days and then inspected and the supper-glue coating was hard and with no soft spots. This spring 2019 I inspected the float again submerging in E-10 for 2 days and still hard with no soft spots. The float weight the same is it did in 2017.

 

[Willyclay]

Thanks for the follow-up report on your status with that great old motor. Enjoy the summer!