'93 25hp 2 stroke Spark Plug Issue??

[TownsendsFJR1300]

Always in neutral...

Shouldn't crank over anyway while in gear...

[Jason2tpa]

Ok. Lets say she starts. Any next steps to keep running. Once lit i recon she stay running.

[Jason2tpa]

She's running. In the future, at least till i get the choke flap on the 2nd carb, it seems this way of starting with throttle wide open might be better than using choke??

[TownsendsFJR1300]

Ok. Lets say she starts. Any next steps to keep running. Once lit i recon she stay running.

Just like your on the water or on the muffs at home.. Nothings any different..

Its probably dry by now anyway..PULL!!

[TownsendsFJR1300]

She's running. In the future, at least till i get the choke flap on the 2nd carb, it seems this way of starting with throttle wide open might be better than using choke??

Just read posts #55 and #57 and fix it correctly...

Do you really want to be have a non-starting motor 3 miles from shore??

[Jason2tpa]

Well guys I wish I had good news to share. As I posted last, she did start up. On the muffs at ramp I let her warm up. Killed engine and started a few times. Launched boat and went out maybe a mile from the ramp to a good fishing spot. Ran great at WOT. Started/stopped a few times. Netted bait. Cranked up and started to head to fishing spot. As I throttled up she bogged down. I turned around to look and saw the fuel line that clips to the tank had unclipped. Ok, no big deal. I must of not had the clip all the way seated. So I attached making sure the fit was good. The ball was tight so no need to squeeze. Gave a pull and nothing. Actually sounded like it was flooded, which isn't a sound I've heard after she's good and warm. The choke was open, of course. Gave a few more pulls. Same sound. Ugh. Let it sit a few minutes. Opened throttle all the way and pulled a few times. Only once did she sound like she was about to get going. Sputtered a little then nothing. This sequence went on for about an hour. Then I gave up. Luckily another boat was nearby and was kind enough to tow me in.

My frustration is tipping over. I know I need to get the 2nd choke flap installed. But once she is started, warmed up, and running, the choke flaps aren't needed. Right? She should have cranked right up after I plugged fuel line back in. If the fuel line had been off long enough while running then I assume the engine pulled all of the fuel from the bowl before shutting down. If this is the case, why was the ball tight? But still, once bowl was filled she should have cranked right up because she was already warm. Shaking my head in frustration.

Big thanks to Dashunde and Townsends for taking so much time. Greatly appreciated guys.

[Dashunde]

Do you really want to be have a non-starting motor 3 miles from shore??

lol... you totally jinxed him!

Ran great at WOT. Started/stopped a few times. Netted bait. Cranked up and started to head to fishing spot. As I throttled up she bogged down. I turned around to look and saw the fuel line that clips to the tank had unclipped. Ok, no big deal. I must of not had the clip all the way seated. So I attached making sure the fit was good. The ball was tight so no need to squeeze.

The bulb should have collapsed due to the fuel pump sucking it dry.
You did have it flowing in the right direction, right?
---> towards the motor.

Also, once you get this thing running keep it running, dont start/stop it a bunch of times.
When you need to stop for something put it in neutral and set it to rev smoothly above normal idle to keep it cleared out.
I probably wouldnt try to "do" anything productive with it until its all sorted out and predictable.

Btw... isnt this latest bogging out problem similar to the original reason you started this thread in the first place.
My guess is you have a few problems with it that are going undetected beyond the missing choke plate.
Is your tank an old metal one? If so, I'd start with replacing the tank and all fuel lines.

The choke was open, of course. Gave a few more pulls. Same sound. Ugh. Let it sit a few minutes. Opened throttle all the way and pulled a few times. Only once did she sound like she was about to get going. Sputtered a little then nothing. This sequence went on for about an hour. Then I gave up.

At any time during all of this did you choke it?
If you believe it became starved of fuel and ran dry, then using the choke would have pulled in a little more fuel for a start.
If you didnt use the choke the sputter you hear may have been its attempting to start on fumes, instead of it being flooded.
At this point it still needs a fair amount of fuel warm or cold.

My frustration is tipping over.

That's the side dish to the steaming time-n-money crap pie I mentioned earlier.

I know I need to get the 2nd choke flap installed. But once she is started, warmed up, and running, the choke flaps aren't needed. Right?

Not always... some are more fussy than others.

She should have cranked right up after I plugged fuel line back in. If the fuel line had been off long enough while running then I assume the engine pulled all of the fuel from the bowl before shutting down. If this is the case, why was the ball tight?

Good question..

But still, once bowl was filled she should have cranked right up because she was already warm. Shaking my head in frustration.

Not exactly... warm does not always mean its ready to go, the fuel has to be there.


fwiw... I have a 1975 Evinrude 15hp that I'm getting fairly irritated with too.
It fires right up, makes good power, runs a small jon in the mid-20's, but when I slow to a idle quickly after a long wide open run it makes a weird noise then dies and requires half-choke to get going again. If I bring the revs down slowly it'll do ok, but the idle is still off a bit for a little while.
Generally, it idles smoothly forever, and I just completely tore down the carb and rebuilt with the full kit.
My guess is it needs reed valves or something, but I'm too lazy to pull it apart that far right now.
That and I smacked a big damn rock (or something) with it the other day... chewed up the prop and dented the lower unit.
I'm not in a good mood about that one and in no hurry to bury myself deeper in it... there's good reason why things end up in the scrap pile or parted out.
Point is anyone who tinkers around with 2-strokes for any amount of time has come across a few that pissed them off real good.
Perhaps find another and move on... who knows, yours might be worth a bunch parted out.

Big thanks to Dashunde and Townsends for taking so much time. Greatly appreciated guys.

Your welcome.
Honestly though, you really picked the worse 2-stroke you could possibly find to learn about 2-strokes.
It's not a Yamaha thing... its a twin carb missing parts, water cooled, ageing craigslist boat motor with a unknown history kind of thing.
There are a 1001 things that could be making it hard to start after its warm, ranging from mud blocking a cooling port resulting in a hot cylinder, all the way down to a clogged/closed vent on a fuel tank.

Start with a "fixer" weedeater or something... the principles are mostly the same, but the weedeater won't strand you a mile from shore.

[zenoahphobic]

Keep in mind that fickle two strokes that have issues restarting , the ignition system needs to work harder when engine is hot.
In the old days, forever fiddling with mixture and getting down to pat the starting ritual and how long to have the choke on, often we're solved with an upgraded ignition system.
I say this because I remember how electronic or CDI made a huge difference.
Just keep that in mind because coils seemingly working (because engine runs) once replaced are known to cure weird starting problems.

[Jason2tpa]

Yes, the bogging was quite familiar. One event i left out was after throwing the net water will accumulate in the stern, where the portable plastic tank rests. In the past I attributed this issue with water grtting in the tank, then the lines, etc. maybe a few gallons a water got back there but arent the tanks impermeable to water? It was a little choppy out there to so maybe some got in through the vent cap. Theoretically shouldn't the tank be able to rest in standing water so long as it doesnt enter through the cap? Otherwise, what the hell? It would be impossible to keep water from getting in the boat and flowing back to the stern.

[zenoahphobic]

Yes, the bogging was quite familiar. One event i left out was after throwing the net water will accumulate in the stern, where the portable plastic tank rests. In the past I attributed this issue with water grtting in the tank, then the lines, etc. maybe a few gallons a water got back there but arent the tanks impermeable to water? It was a little choppy out there to so maybe some got in through the vent cap. Theoretically shouldn't the tank be able to rest in standing water so long as it doesnt enter through the cap? Otherwise, what the hell? It would be impossible to keep water from getting in the boat and flowing back to the stern.

Sure the plastic tank should be able to float around in water provided none of it gets near the cap. It is appropriate that water flows to the stern where a pump can empty it or even a convenient bailing spot, unfortunately most fuel tanks are there also.

Water getting into a tank should really not be an immediate problem unless your using ethanol laced gasoline. If not water falls to the bottom and you should have a shorter pickup tube to avoid it being sucked into the fuel line. Of coarse do everything to avoid the vent getting water to it, and a shorter tube will reduce your fuel capacity but if you have another container and a fine filtered funnel you can actually separate the water from the remaining fuel and possibly reuse it if the job is done right.

I've mentioned ethanol; not a good idea to use in a boat. Also starting problems could be exacerbated if using high octane fuel? Yes, because the violatile components evaporate quickly leaving a fuel substantially less in octane. Using this higher octane fuel makes for difficult starting leaving plugs very wet as you described above.

So the advice is fresh non ethanol and low octane (appropriate rating) fuel, and not withstanding getting carby fixed, keep in mind your ignition system (as I previously posted) may not be up to scratch.

[Jason2tpa]

Ive been using regular unleaded (87) at the gas station. I believe it has 10% ethanol. Sounds like I need to find a station that offers 100% FREE ethanol fuel. The carbs were cleaned when the kit was replaced probably 3-4 weeks ago.

Sure the plastic tank should be able to float around in water provided none of it gets near the cap. It is appropriate that water flows to the stern where a pump can empty it or even a convenient bailing spot, unfortunately most fuel tanks are there also.

Water getting into a tank should really not be an immediate problem unless your using ethanol laced gasoline. If not water falls to the bottom and you should have a shorter pickup tube to avoid it being sucked into the fuel line. Of coarse do everything to avoid the vent getting water to it, and a shorter tube will reduce your fuel capacity but if you have another container and a fine filtered funnel you can actually separate the water from the remaining fuel and possibly reuse it if the job is done right.

I've mentioned ethanol; not a good idea to use in a boat. Also starting problems could be exacerbated if using high octane fuel? Yes, because the violatile components evaporate quickly leaving a fuel substantially less in octane. Using this higher octane fuel makes for difficult starting leaving plugs very wet as you described above.

So the advice is fresh non ethanol and low octane (appropriate rating) fuel, and not withstanding getting carby fixed, keep in mind your ignition system (as I previously posted) may not be up to scratch.

[Jason2tpa]

Hey gang here's an update. I think I've narrowed down the issue (other than 1 of the 2 carbs not having a choke valve). Tried starting it today....at least 15-20 pulls with no luck using the choke on choke off procedure y'all suggested. There was a guy on my storage facility lot (a trucker) who was watching me and came over to offer a hand. He looked at each plug while I pulled flywheel. Each plug was firing. Interesting....the plug for the cylinder that is feed by the choked carb was very wet...the other plug dry. Guess that makes sense though, right. So anyway, after both plugs were back in the engine started. So what I did was duplicate the exact same scenario that occurred yesterday when I took boat out. I unplugged fuel line from the tank while engine was running. The engine bogged down to cut-off due to lack of fuel. Inspected the bulb and it was somewhat empty. That's a bit peculiar, right? If the fuel pump was working correctly it should have pulled every bit of fuel from the carb then the bulb before cutting off. Right? So anyway, I plugged fuel line back in, squeezed bulb till firm and pulled flywheel. Nothing! Which I'm kinda glad it happened while this guy was there so at least someone could witness what was going on lol.

Here's the kicker because I think this is a indication of what's going on. As I was pulling cord, small amounts of fuel would leak out of the bottom throat of the carb (the carb that can be choked). Now before you ask, the carbs had a cleaning and new kits 3-4 weeks ago. Everything was inspected and replaced by a yamaha mechanic. So after pulling cord about 10x with no luck, he pulled the bottom plug and it was dry. Pulled top plug and it was dry. Basically both of us agreed that no fuel was getting to the chamber. Fuel pump, right? Now I inspected fuel pump the other day. Opened it, inspected gaskets and diaphragm. Looked good, though I'm a amatuer. I know the pump works because I pulledtnhe hose going from pump to carb. Watched it squirt fuel as I pulled cord. However, I don't know if the PRESSURE from the fuel pump is adequate. Can the diaphragm of the fuel pump become stretched or weathered? So much so that it works, but just doesn't work good enough? I've never replaced the gasket/diaphram of the fuel pump so i'm sure it could use it. And inexpensive. What do y'all think? Could this be the major factor to my issue? Many thanks!

[Dashunde]

Hey gang here's an update. I think I've narrowed down the issue (other than 1 of the 2 carbs not having a choke valve). Tried starting it today....at least 15-20 pulls with no luck using the choke on choke off procedure y'all suggested. There was a guy on my storage facility lot (a trucker) who was watching me and came over to offer a hand. He looked at each plug while I pulled flywheel. Each plug was firing. Interesting....the plug for the cylinder that is feed by the choked carb was very wet...the other plug dry. Guess that makes sense though, right.

If thats the case you've got a fundamental starting problem... one cylinder gets enough fuel to fire, but it might not be its turn when you pull the cord, meanwhile the carb that is due to fire doesnt have enough fuel and it all gets messed up from there.
Sometimes you get lucky and the right amount of fuel aligns with a cylinder that is ready to go.

The idea is that at least both cylinders will be treated the same, instead of one being flooded by its choke and the other is left empty.

I unplugged fuel line from the tank while engine was running. The engine bogged down to cut-off due to lack of fuel. Inspected the bulb and it was somewhat empty. That's a bit peculiar, right? If the fuel pump was working correctly it should have pulled every bit of fuel from the carb then the bulb before cutting off. Right?

Nope.
When the hose is disconnected from the tank the valve closes in the hose's connector, that pretty much stops the flow.
It would only get every drop if the fuel line was held straight up above the motor and something was stuck into the connector to open the valve.
With it disconnected/sealed off at the inlet end it will only suck as much as it can before it can not overcome the vacuum in the sealed line.
When you ran it disconnected did the bulb go flat or just a bit soft??

As I was pulling cord, small amounts of fuel would leak out of the bottom throat of the carb (the carb that can be choked)... So after pulling cord about 10x with no luck, he pulled the bottom plug and it was dry. Pulled top plug and it was dry. Basically both of us agreed that no fuel was getting to the chamber. Fuel pump, right?

Those two conditions above contradict each other...
It appears to be pumping enough to leak.
Float stuck open or not set correctly?

Now I inspected fuel pump the other day. Opened it, inspected gaskets and diaphragm. Looked good, though I'm a amatuer. I know the pump works because I pulled the hose going from pump to carb. Watched it squirt fuel as I pulled cord. However, I don't know if the PRESSURE from the fuel pump is adequate.

Correct. Squirting out into thin air is easy, sucking from a tank and pushing past a float needle is a different story.

Can the diaphragm of the fuel pump become stretched or weathered? So much so that it works, but just doesn't work good enough? I've never replaced the gasket/diaphram of the fuel pump so i'm sure it could use it. And inexpensive. What do y'all think? Could this be the major factor to my issue? Many thanks!

It certainly will deform and stretch out over time.
A fuel pump is also not the kind of thing you take apart without having new parts to put back in, and in exactly the correct way.

Here is what I have come up with after many hours...
- You need to be sure your tank is clean, water-free, and venting... or just buy a new tank, us the old as spare.
- You need a new fuel line & bulb, as well as all inner lines.
- You need a new carb with a proper choke or get the flap installed into your existing carb, somehow.
- You need a new fuel pump by default... you took it apart and didn't replace anything, it could be sucking air now.
- You need to be absolutely certain the floats were set correctly when the carbs were rebuilt.
That means pulling them off and checking...
With the carb upside down and the float needle seated, the float should sit level with the rim of the bowl/carb housing.
If the end opposite of the hinge pin sits too low the bowl is overfilling and could cause flooding.
If the end opposite of the hinge pin is sitting too high the float will close prematurely.
While your at it, check both floats for buoyancy. (drop them in a glass of gas)

I'd also warm it up and do another proper compression test before I did any of those things listed above.
They need to be north of 90psi and fairly close in average pressures with no leak-down over time.
(Research the proper method)

Until you do all of those things we're really just guessing away a lot of time.

[Jason2tpa]

Bulb was soft not empty. The tank is fairly new so id opt to keep and dry it out. Lines and bulb are 4 months old. Replace, really?

[Dashunde]

I guess not replace, but you seem to have ecountered a few issues with the tank/vent/disconnects, no?
The other odd thing is the firm bulb after it was disconnected from the tank while you were running on the water vs a soft bulb with the line disconnected on dry ground.
I'd expect opposite results.

We've all gotten deep into this, only to discover midway through that you've left out some very important details - several rounds talking about it being hard to start - only to find out later that you left out the part about the missing choke flap.
That was a hugely important element needed to help you.

Honestly though - and I'm not trying to be mean or condescending - your in over your head with this thing. You don't have the experience required to trace the problems accurately, convey your findings to us, or the hands on technical skills (yet) to work through some of these problems to arrive at a reliable seaworthy motor.
Twice now this thing has left you in undesireable positions on the water, perhaps even dangerous positions with outflow tides.. and it still doesnt have the basic requirement of having the second choke flap installed.

I really suggest you take it to someone who works on outboards regularly, have them go through it, then they test it on water, then instruct you on its finer operating details.