Motor won't run

[c451812]

Hello all: I need some help. I have a 1992 25hp Evinrude tiller steering, electric start motor. The motor was running fine until last Saturday. While running at almost full throttle, the engine caughed, I looked at the after-market fuel tank and the sides were collapsing, I then opened the vent and the motor ran fine, and the tank regained it's normal shape. About 5 minutes later I went through a no wake zone for about another 5 minutes at a very slow speed, Then the motor died and would not restart( fortunately very close to my slip}. Since then I have replaced the tank with an OEM tank and hose. Taken the carb off and cleaned and inspected it. Checked the filter and disassembled the fuel pump and it "looks" o.k.. Now if I use the primer I can hear and feel the gas going to the carb, and the motor will run until that initial charge of gas is gone. I can keep it running with the primer in the warm-up position and throttle-up at the same time, once I let go of the throttle it dies. I hope I have given enough info, I can't think of anything else. Sorry for the screw-up in the posting, I hit the wrong button. Thank you, Joe Carroll

 

[BugEyes]

Re: Motor won't run

If it runs when you prime it and obviously don't get gas otherwise. Then it sounds like it's fuel pump problems. That especially since you already replaced the hose to the tank.

 

[OBJ]

Re: Motor won't run

High Joe.<br /><br />From what you describe in your post, I think a carb cleaning is in order. Disassemble the carb, soak it out and then blow out the passages with canned carb cleaner. Follow up with compressed air. It sounds as if the idle circuit in the carb is plugged. As long as the throttle plate is cracked open, your getting fuel from the high speed jet. Close the throttle plate and the motor dies.<br />I would also suggest a carb kit for the overhaul. You can get them from your local John/Rude dealer.<br />Keep us posted if you have any questions or anything else to add....thanks.<br /><br />Edit: Just got to thinking...are you sure you got the fuel pump back together right? There is a tiny spring in there that can get lost if your not watching for it.

 

[fireman57]

Re: Motor won't run

First off, welcome to iboats. To add to OBJ's post when you have the fuel pump apart, really tough(four bolts) inspect the diaphragm in it for small holes or tears.

 

[c451812]

Re: Motor won't run

GENTLEMEN: let me say thank you for taking the time to help me. I just left the boat,I started it the way I normally do, and kept it running by giving it gas. It even ran for awhile while not holding the throttle, but eventually died. While I was holding the throttle I was watching the choke plate, now, is it supposed to close completely when the throttle is released ? or should it be open a crack ? Mine closes completely. I want to try as much as I can before taking that carb off again. I did inspect the fuel pump and could'nt see anything wrong. Now here is the real stupid question. On a factory gas tank there is no vent at least that I can see, so should the cap be " cracked open " a bit or closed tight ? I'll now go check-out my manual to see what I can get out of it, their troubleshooting section does'nt help me much. Thanks again for your help. Joe

 

[ED21]

Re: Motor won't run

The factory gas tank has a vent that automatically opens when you plug in the hose.<br />A spring activated pin opens & closes the vent when the fitting is pushed on or off the tank.

 

[OBJ]

Re: Motor won't run

Well...that does depend on which "factory" you get the gas tank from. OMC/Bomby tanks have, as posted by Ed, a spring loaded vent that opens when the connector is plugged in. Some tanks have a vent on top of the filler cap that must be opened by hand to vent the tank. Bottom line is, the fuel tank MUST have some kind of ventilation.

 

[c451812]

Re: Motor won't run

Thanks again fellas, I have the type Ed described. Joe

 

[rwise]

Re: Motor won't run

c451812<br />The choke plate should be fully open when normally running at idle or at WOT.

 

[c451812]

Re: Motor won't run

Thank you, rwise: So that I'm on the same page as you, I used the word " choke -plate" refering to the piece that is seen when looking into the carb, and "open" to mean that when the throttle is increased on the tiller, that plate flips up or open so that you can look further into the carb. Using that description, when I take my hand off the tiller and the throttle rolls back to slow, this plate closes completely. What has me puzzle is that the motor had been running fine and no adjustments were made to anything. Another thing that I found was that the slow-speed idle screw was all the way in and seated. I really think that something is out of adjustment, and maybe someone on this board has expeience similar problems. The carb has been cleaned and all needles appear to be in good condition. There are no tears in the fuel pump membrane, and no leaks. What I'll try tomorrow is adjustting that throttle plate, to stay open when I release the throttle. I could'nt find any description of it in my manual. Thanks again to everyone. Joe

 

[Barnacle_Bill]

Re: Motor won't run

I'm betting you damaged the fuel pump diaphram. If the sides of the tank were collapsing that much, you were putting a heck of a strain on that diaphram. They can only take so much. Your having to pump the primer bulb helps verify that.

 

[cajun555]

Re: Motor won't run

c451812, I'm not a wrench, but you mentioned in your last post that the idle adjustment was all the way in. If its all the way in then the motor won't run at a idle. Try opening the idle screw atleast 3/4 turn out from a lightly seated position.<br /><br />Just my 2c worth

 

[umblecumbuz]

Re: Motor won't run

I smell a bit of confusion here. The throttle butterfly will progressively open as you increase revs, and it will SEEM to close completely when you shut down. The choke valve will stay where you put it regardless of revs.<br /><br />The slow-running adjustment is to even out the idle. As has been said, crack it open 3/4 turn - let engine warm thoroughly, then adjust little by little, giving motor maybe half a minute each time to settle, until you're happy with idle.<br /><br />I suspect there's more than one reason why your motor's not running sweet. Eliminate the tank first - even if you think it's venting properly, try running with the filler cap loose to see if it makes a difference. If it does, you've removed one problem. If it doesn't - forget the tank and start looking further, as above.<br /><br />Ciao

 

[OBJ]

Re: Motor won't run

You are right Ciao....there is some confusion. Maybe we need to un-confuse here a little.<br /><br />First...there is no choke plate...just a throttle plate which should be completely closed at idle. Also in the fuel delivery, did you try a different fuel line and primer bulb? Could have sucked something out of the fuel tank that is partially plugging the fuel line. Little far out but possible.<br /><br />I still believe he needs to remove and properly clean/rebuild the carb. From his first post, the engine would stay running if the primer was open. And while your at it, replace any fuel lines "under the hood" that have become hard and have lost their flex. These tend to lose grip at connection points.<br /><br />Fuel pump...my suggestion would be to get a fuel pump rebuild kit and redo the pump. These things never come apart and go back together air tight. A kit is cheaper than a new pump.<br /><br />Last, Joe...get a OEM service manual for all this. It'll show you what to do and how to do it including setting the sync and link and carb low end adjustment.

 

[jimalsk]

Re: Motor won't run

I have to agree with OBJ that it sounds like the fuel pump. The strain on the fuel pump diaphram has stretched it.

 

[fireman57]

Re: Motor won't run

Yaaaahhh!!! Looks like I might have gotten one right. I'm strictly backyard from working on my three engines. The techs have the knowhow and years of experience. People like OBJ, Joe Reeves, rodbolt, JB, and others are great to have the time to help on this forum.

 

[c451812]

Re: Motor won't run

Well fellas, here is what's happening. The local Eveinrude guy is going to let me use a known to be O.K. fuel pump. I'll install that and see what happens. If we can't get it running, then the carb and fuel pump will be rebuilt. This wont happen until Tuesday. So I'll write the results asap. Thank you, Joe

 

[c451812]

Re: Motor won't run

UPDATE; Both the carb and fuel pump have been cleaned and all looked well with both, but new parts were installed. Still won't run for more than 1 minute. The mechanic is now getting elaborate, thinking that maybe the key in the flywheel sheared or deformed and caused the timing to be out, or it may need a new " Powerpack ". I'm in the dark about those things. I really don't think this guy would rip me off, but I do think that he has not spent enough time with the fuel system. We'll see.

 

[fireman57]

Re: Motor won't run

A sheared flywheel key could be the culprit. It is easy to check. Just pull the flywheel and inspect it. If you have a puller then this is an easy task. You can check the powerpack yourself. Do a spark test and make sure that the spark is bright blue and jumps at least 7/16 of an inch. If it is yellow or nonexistent then I would change the powerpack.