Repair #2

[SVNET]

Well,

I am well into repair #2, getting the motor to start.

I have a clean plastic tank with fresh premium grade gas mix.

I have brand new clear hoses which show gas reaching all the way to the carburetor.

But, when I pull to start, most of the time I get nothing and once it a while it will run for 30sec max.

I have unplugged the spark plug cable and laid it in front of the spark with hope, but have not seen any spark either.

Whats next ?

I took a look at all the visible cables and everything seems very clean, no rusty connection any where.

I know there are some electrical connections under the magneto but I have not been in there yet.

Any hits or other ideas to try out ?

Regards.

 

[bassboy1]

Test your spark. Either with a spark light, or by taking off the cable, unscrewing the plug itself, and ground it to the block. If you don't ground it, I guarantee you will not have spark.

 

[SVNET]

Test your spark. Either with a spark light, or by taking off the cable, unscrewing the plug itself, and ground it to the block. If you don't ground it, I guarantee you will not have spark.

Could you elaborate more on this point, I feel as if I did not get everything here...

So I should unscrew the plug itself from the block, leave it hook to its cable and get the plug close to its own thread on the block hole, it should spark from there ?

 

[Captain Ahab]

You got it SV - just have someone hold the spark plug against something metal on the engine and start cranking (I think you have a pull start so start pulling) - you will see a blue spark

It is probably not your spark if the motor runs for a bit and them quits. You can try removing the bowl at the bottom of the carb and seeing if the float is working - also, clean out the bowl if there is any sediment

I know you said something about a bad fuel pump - have you tested the fuel pump (just unhook the fuel line and start pulling - fuel should pump out)

Finally, does the carb have a choke? Is that working?

 

[ben2go]

The end of the spark plug needs to be against bare metal on the engine.This will allow the spark plug to fire.If the spark plug isn't touching bare metal,it will not produce a spark.

 

[SlimeTime]

You have spark or it wouldn't run for 30 seconds. Look under the fuel pump for a screen that may be plugged or cracked diaphram. I say your problem is fuel, float (or sticking needle) could be another posibillity.

ST

 

[SVNET]

You have spark or it wouldn't run for 30 seconds. Look under the fuel pump for a screen that may be plugged or cracked diaphram. I say your problem is fuel, float (or sticking needle) could be another posibillity.

ST

Thanks all for the idea to test for sparks, it works and I do have spark so that is not the issue...

When I pump fuel manually I see fuel go through and past the engine owns pump and reaching the the carb front door.

The problem must be either the fuel pump or the carb itself, but we do have spark and available fuel up to the fuel pump.

I will take apart the fuel pump to check it and take a couple of pictures for you guys...

 

[Zum]

If you keep squeezing the ball,does your motor keep running?
Just keep manuallly squeezing it for awhile and see if it stays running longer.

 

[SVNET]

If you keep squeezing the ball,does your motor keep running?
Just keep manuallly squeezing it for awhile and see if it stays running longer.

yep, it is heading that way...

Everything happens so quick that it is hard to squeeze at the same time, and I can never tell when is going to do a 30 sec run.

I did took the fuel pump apart, cleaned and put it back together, then I prime it well squeezing it, and that time it actually ran for over a minute...

I think the issue is fuel pump related...

does it matter that there is air in the fuel line?

below are pictures of the fuel pump parts, could someone explain to me the concept behind this pump style ?


how it works, the membrane ?

how does the inner parts looks to you?

sorry, typing with one hand, got my youngest on my lab.....

 

[SlimeTime]

So was there any dirt in it?

Did you take the small filter out & clean it as well?

Does the primer bulb get firm when you pump it?

+ & - pressure from the crankcase operate the diaphram back & forth, like a plunger. Looks don't always mean anything if there's a small hole or tear in the diaphram.

I'd probably rebuild the pump & carb & be done with it.

ST

 

[SVNET]

There is not much to the pump, so a rebuilt I guess will be to replace the membrane ? Where would get that locally ?

I think sears wants $170 for a new fuel pump... and $200 for a new Carb...

picked up the yellow book and was calling people around looking for a local mechanic... None want to work on such small engine...

Finally found a guy at a local marina that usually doesn't like to work on such small engines but agreed
for me to drop it up to diagnose the problem for $90 1hr labor which can be apply to the repair if I want to repair it...

The guy advised that these sears small motors are a pain in the rear, the motor were built in Mexico for Sears and the carb system was not well design so it is like a disease, they all suffer from it.

My guess is that he will just clean the carb, but if that ain't it I will be down $90 or who knows how much to repair it...

 

[SlimeTime]

Might see if NAPA can help on parts (if you have one local), get the #'s off the motor. I was able to get Chrysler fuel pump & carb kits from them. I think Ben listed the Sears parts website at one time, I'd think they have rebuild kits (both should be less than $40-50 I'd have to think.

$90 an hour for mechanic? :roll: He may as well have told you he didn't want to work on it......I'd have had to laugh at him. I don't think you'd have a problem rebuilding them yourself, you've done pretty good so far. Take pics if needed to help with reassembly.

ST

 

[Andy]

I'd probably rebuild the pump & carb & be done with it.

ST

I agree. with a hole so small you can't see it, it will not function correctly. kits aren't very expensive, and would save you alot of headache on troubleshooting what is the problem only to be solved by a rebuild kit anyways.

 

[SVNET]

Good, out on the hunt for rebuild kits...

As you all can tell, I am not the smartest guy on the block but I can get around when I put myself into things, and with my limited knowledge of this kind of stuff, I must admit that I am a bit, uhmm whats the word, about this whole fuel pump concept.

You know how much it takes for me to manually pump gas all the way up to the motor area, I just don't see how that little membrane can keep up, I think that is a system design to fail... If that motor is to be run on rough waters and under high demand, it will be Chaos...

So let me try to explain this to see if I am getting the concept...

As the piston goes up and down, on the rear end it must create some air flow as it push down, and that is the pressure that should push and suck this membrane back and forward and hard enough for the suction of the membrane to open and close those two little metal plates that act as gate keepers to the gas coming in and the gas going out ?

Mean while the membrane is some what see through, meaning gas can go through it and into the crank case via the little hole that allows for the air pressure to come into the fuel pump chamber.

Is that how it works ?

How much power does it takes to keep the carb full of gas at all time without overflowing it, which that's the job of the float, even if too much gas comes in the float keeps control...

how about if one buy pass the pump and let gravity keep gas on the line at all time...

 

[ben2go]

Might see if NAPA can help on parts (if you have one local), get the #'s off the motor. I was able to get Chrysler fuel pump & carb kits from them. I think Ben listed the Sears parts website at one time, I'd think they have rebuild kits (both should be less than $40-50 I'd have to think.

$90 an hour for mechanic? :roll: He may as well have told you he didn't want to work on it......I'd have had to laugh at him. I don't think you'd have a problem rebuilding them yourself, you've done pretty good so far. Take pics if needed to help with reassembly.

ST

Yep.Some of the NAPA stores that have been in business for 30 years or more sometimes have parts.If your engine fly wheel says tecumse you are in luck.Sear's still has parts.Fuel pump element is around $15 to $20.Sad thing is sear's no longer services outboards.At least none around me does.I have a 1980 Gamefisher that I am working on.

Here's the website for sear's parts.Just enter your model number where it says model number.It will list everything available.Ignition parts are straight from old tecumse push mowers.Those parts are fairly cheap from a local lawn mower shop.

https://www.searspartsdirect.com/partsdirect/index.action

 

[Captain Ahab]

does it matter that there is air in the fuel line?

YES - you probably have an air leak somewhere along the line. Make certain that all you fittings are tights,


DOES THE BULB GET HARD WHEN YOU PUMP IT? IT SHOULD GET FULL AND HARD AND STAY THAT WAY - IF NOT, YOU HAVE A LEAK

 

[phased]

I would think if the pump diaphragm does not have a crack or split and is not hard (still flexable) it is OK. Hold it up to a good light source and check it. And if the little filter is not clogged it should pump.
Did you take the bowl off the bottom of the carb and check the float as slimetime suggested? That is a quick and easy thing to check. It should swing freely and the needle valve should move freely. If the motor has not been run in some time and the float is stuck down this seats the needle valve which will not let gas enter the carb even if the pump is pumping. It may be letting just a small amount of fuel get through thus allowing it to start but not run.
Just a quick thing to check without having to spend any $$'s.

 

[SVNET]

does it matter that there is air in the fuel line?

YES - you probably have an air leak somewhere along the line. Make certain that all you fittings are tights,


DOES THE BULB GET HARD WHEN YOU PUMP IT? IT SHOULD GET FULL AND HARD AND STAY THAT WAY - IF NOT, YOU HAVE A LEAK

I will go through all the connections to make sure they are well tighten, but then how do I bleed the system...

Just by looking at the clear hoses I can tell there is big gaps of air in the houses...

Second, the carburator is in such a place that for me to take the bottom cup I would have to lift off the whole engine...

I will have to check if there is a way to get rid off the bottom plastic plate... which will give me access to the carb.

If I have to pull up the engine, what is the relationship between the top part and the bottom part, is there like a gear shaft that I will be able to just lift up ? Just want to get an idea....

 

[Captain Ahab]

You do not bleed the system - the air will get forced out through the carb. 1st try to get the air out and see if it runs before you start lifting the engine off the lower unit

 

[SVNET]

Well,

Here is a good write up about fuel pumps... I just have a lot of details to check up on before I dive into anything mayor....

Now I want to make sure the compression is good too... I will pick up one of those compression tester today...

https://www.boatpartstore.com/fuelpump.asp

https://www.boatpartstore.com/fuelpump.asp

Standard outboard fuel pump troubleshooting (All brands/models)


There isn't really too much involving fuel pump troubleshooting, and I'm rather amazed at how many fuel pump kits we sell in a years time, as standard outboard fuel pumps don't really act up that much in my experience of 20-some years of wrenching. If you feel though the fuel pump is your problem, read on.

A standard outboard fuel pump is a simple device that operates off the pulse of an engines cylinder. A basic rubber fuel line connects the fuel pump to a pulse valve (some models of fuel pump attach directly to the block with a gasket, sealing pulse passage to cylinder), which is normally threaded into the block with provisions of a clear passage to a specified cylinder. The up and down stroke of the piston in the specific cylinder is what causes the fuel pump diaphragm to flutter, resulting in pumping fuel from tank to carbs.

So how do I know the fuel pump is doing what it is suppose to?
As described above, the fuel pump requires an adequate pulse from the cylinder that it is attached to, so first thing is to make sure compression on that cylinder is up to snuff or the fuel pump can't do it's job. If compression checks out, then next thing is to check fuel pump pressure. All non fuel injected outboard motors operate with a fuel pump pressure of about 5 to 7 psi. If consideribly less than 5 to 7 psi exists between fuel pump and carb/s, the motor is likely to be starving for fuel causing idle and/or upper rpm operation to suffer, not to mention a dangerously lean condition.

So what if everything to do with pulse supply to the pump is good, but I still suspect the pump has a problem?
Although I mentioned not experiencing many fuel pumps actually being bad, it is indeed possible for either the diaphragm, check valves, or other problem to develop in a fuel pump. If it's plainly worn out, then so be it, install a kit or replace pump entirely, but I would suggest checking all other things in this troubleshooter page before just taking it for granted your time and money spent on a fuel pump kit or replacement pump will solve your motor's woes.

Could anything else cause the fuel pump to not provide adequate fuel supply to the motor?
The answer is yes. There could be a restriction or loose connection from tank to fuel pump, amongst other things. Assuming you have no leaks (including pinholes in hoses) anywhere in-between, the following would be things to check for:

Fuel tank internal pickup tube clogged, broken off, or otherwise defective.
Anti syphon valve located on tank (is so equipped) could be defective (check ball/spring).
Any kinked hoses between tank and pump.
Defective in-line squeeze bulb (usually the internal check valve).
Defective or incorrectly attached fuel line connectors.
Clogged fuel filter.
Inadequate fuel tank vent or kinked vent hose.

Thats about all there is to a standard outboard fuel pump trouble shooting guide. If you should run across a rare or "quirky" condition not covered here, you are always welcome to contact us with your questions. Happy pumping!