Evinrude 35hp 1957 won't start

[krazykooter]

Ok here is the list of things I've done to this motor...
1. Rebuilt carbs adjusted float so it's level with bowl when seen from upside down
2. Set the top needle at 1.5 turns out
3. Set the bottom needle at 1 turn out
4. Use 24:1 ratio twc3
5. Added fuel pump to single line instead of ole 2 line vacuum
6. Rebuilt the starter motor so it spins nice and strong resurfaced communitcator and used communicator oil on existing brushes now spins nice and strong...
7. Replaced electrical solenoid
8. Replaced motor head (blew 1st one threw a rod)
9. Added kill wires to respective points so when shut off position engine dies quickly due to shorting out to ground to kill spark
10. Add new packing for carb needles so they would not spin freely..


Ok now for what is happening engine will start when I spray gas into carb throat engine will rev high then keep going after a few mins but seems that the idle of it is non existent even when I adjust low speed needle.. I did not adjust high speed needle (lower one) at all when trying to fine tune to idle for shift speed... I've been taking apart this carb and engine about 5-10x's and I'm at my wits end on why doesn't it want to start without help of spraying into the carb why it doesn't seem to idle... My patience on get this baby running right is running thin... I've been researching these forums to see what I'm doing wrong... Please advise me where I may over look what I did do wrong...

 

[oldboat1]

Woof. Too much going on. Sounds offhand like a vacuum leak. You replaced the powerhead, rather than rebuilding it, right?

 

[krazykooter]

Thanks, I will replace the lines coming out of the reed valve area to ensure they are totally sealed the powerhead was used (not rebuilt) it seems to run fine once it's running but it's been a tough road trying to diagnose this problem... I will double check compression numbers to ensure everything is kosher on that side of the engine... And when it does run it sure smokes me out so I'm really wondering if it may be something so simple as gas gone bad as well... The 6gallon tank was filled up only a few weeks ago and always sealed when not in use for tests...

Oh forgot new spark plugs where added to the list of what has been done as well..

 

[oldboat1]

Can post a pic of your fuel pump conversion, and folks can comment. Pulse source is normally at a bypass cover. (Not sure whether you can tell much about the smoking at the moment.)

 

[krazykooter]

Pics of gas lines

 

[jimmbo]

Ok what hodge podge collection of parts have you got there? The block looks the colour of a mid 70s 40hp Johnson, or an early to mid 50s 25hp. In the 1st pic, it looks like the hose is cracked. That was the pressure hose, I think. It also shows an oil recirc pipe, a 57 block would have what was called a puddle drain valve in that spot. The bypass cover with the pulse line on it is painted in 1957 evinrude blue. In the 3rd pic, the fuel line going into the pump is the right size, but the line going out of the pump to the carb is way too small. There is another hose, also blocked, that one went to the intake manifold, purpose unknown

 

[F_R]

That is a 1955 25hp Johnson powerhead. So if you have a 35hp carburetor on it, you have the wrong carburetor. They look similar but are not the same. Maybe it will work, maybe not. But you are adding to a list of possible problems.

The fuel pump is supposed to be installed right side up. Otherwise, you run the risk of air locking when the bubble inside can't clear itself. Maybe it will work like that, maybe it won't.

What kind of condition is the ignition system in? You aren't trying to run old dried out and cracked 1957 coils are you? The plug wires look suspicious in the picture.

We can't tell if you have the carb / spark advance sync set up right or not.

One turn out on the high speed needle is too much. On the other hand, you are having to squirt gas in it to get it to run, so who knows??

Lastly, the 1955 25hp powerheads had serious problems on certain models. Don't know if you have one of those or not, or if you do is is OK or not? I don't suppose you have the complete model number it came off of?

 

[krazykooter]

Power head numbers 25034 05085 showing 1958 35hp
The original motor numbers 25924-15726 showing 1956 30hp

I've known that this powerhead is not the original McCoy the Original blew a rod while a test of the engine went critically wrong (carb leaned out and engine Rpms went sky high) after my research of the two power heads they are very similar to each other other then the size of the stoke of the cylinder. All the parts bolted right on without any issue at all..

 

[krazykooter]

The conversion was done by a boat mechanic (I had to help him thru what to do) so I'm very reluctant to send out the motor to another mechanic. Hence why I'm here asking questions I know it may look like a mix match of parts on this motor but I did put a lot of heart and soul into her now just to walk away...

Coils under the flywheel are in perfect condition the wires are coated with liquid tape to ensure the insulation is sufficient enough so it doesn't lose spark along the wires... When re gaping the points I've set them .020" at the "O" of top I don't have the tool to set them..

The only question I have is the two plugs for by the reed valve is that correct?

 

[HighTrim]

TOP means just that, the TOP of the cam. You set the points gap to 020 at the widest point of the cam, that MAY be at the O, but Im not sure.

 

[HighTrim]

That powerhead is def NOT from a '58 35hp, just FYI....as Frank stated, its a '55 25hp powerhead. Are you running the 30hp carb on it from your original motor?

 

[krazykooter]

Everything except the powerhead is 30hp 1956 the emblem on the powerhead is the numbers I've stated above.. I took a chance on an eBay powerhead... So if I have to replace it again I'm switching out the motor to my 6hp fisherman... The compression on it is 90psi hot and cold I know that seemed a bit low compared to my prior powerhead again I gave the motor another college try and I'm totally at wits end...

 

[jimmbo]

90 psi is pretty good for a 1955 motor, they weren't high compression engines. Buying powerheads on ebay is really buying a Pig in a Poke. If I remember right the 25 and the 30 had the same displacement, but the 25 was rated @4000 rpm while the 30 was @4500. The 57 - 59 35 were larger displacement and also rated @4500. Don't think if you prop the 25 to spin 4500+ it will be making 30hp. It won't. To get the extra 500 rpm the porting was different and the compression was upped slightly

 

[F_R]

A 1956 30 hp was red (Holiday Bronze). A 1955 25hp was green. Yours sure looks green to me.

 

[Chinewalker]

Is the gasket between the center of the carb bowl and the standpipe plants in place?

Also, the hp difference between 25 and 30 comes from compression ratio, not the stroke. 30 is 6:1, 25 is 5:1. Cylinder heads are not interchangeable.

 

[krazykooter]

Ok ok ok... The amount of info is great but how do I figure out the issue of it not running right I'm fine if I can't zoom at WOT at 4500rpms I want to be able to putt putt up the river and shut the engine off and restart it again I'm being very simple... I did have the motor running for a bit she started to sound like she was almost getting there on the settings then caput nothing again... I'm just trying to get her running and idling so I can throw her into gear and putt putt like I said... I really think the carb is the real thorn in my side I just don't know where everything went wrong... I've rebuilt carbs on various small engines and motorcycles but I really think I've met my nemesis with this one...

I did find another powerhead from a 35hp and I did see the difference in color (again) and the cylinder heads is it better to do another swap or try to beat my head into a wall trying to get this motorhead working?

 

[oldboat1]

Let's see -- think I'm seeing the pressure fitting plugged off (pic 1), although it looks like the hose is split up at the fitting. Not sure if you might have a leak at the pulse hose (pic 3) -- think it would be good to add a clamp at the pump. (Also not sure whether that pump operates effectively upside down.)

Have been unable to figure out how the carb is plumbed (fuel pump to carb). The filter bowl would be overkill -- and can't figure out whether it's functional anyway (or how). In any case, I'm baffled. The plugged hose belongs to the filter, it appears (i.e., not the pressure hose shown in pic 1.) But then again it looks like it could be routed from the pressure fitting....

So where in the devil does the fuel pump feed attach to the carb? Maybe the filter bowl is plumbed in, but incorrectly(?) If it's functional, the top would have a feed in from the fuel pump (in your case), and a hose to the carb.

Think offhand you need to get the filter bowl out of the mix, and see if you can get the pump to work properly. dunno....

 

[Chinewalker]

As asked above - is the small round gasket present between the carb bowl and standpipe inside the carb? It's often missing or neglected and needs to be in place.

 

[krazykooter]

As for gaskets the only ones replaced are the bowel and the gasket to the reed plate / engine port where exactly is this gasket in relation to the carb? If it was missing prior to me owning it I'm not sure exactly the position of it and where it goes

 

[Chinewalker]

No Title

With the bowl off, there's a bit in the center of the carb that sticks down into the bowl. It houses the main jet that feeds into the carb venturi. There's a gasket that should seat between that center tube/jet and the hole in the center of the carb bowl. See pic: