Oh Boy! need help 2004 F150 2 stroke carb not firing one cyl

[ultrasport]

Hey guys hopefully someone can help me out. Changed plugs today 5 were normal black wear and one looked brand spanking new. New looking plug came from starboard bottom cylinder. Checked spark that cylinder is getting spark from wire to plug. Seems as if the cylinder is not getting fuel. Put new plugs in ran and pulled out plug again the one looks brand new. Also since I bought the boat in august have not been impressed with fuel consumption and power. I know my WOT was a little low only 4600 RPMS. There is fuel lines feeding what looks to be a manifold right behind the carb, is there an injector in there that may be clogged? Should I run a compression test on that cylinder. Motor only has 240 hrs. Thanks guys really hope this isnt too expensive plus I wanna fish next week.

 

[ultrasport]

plugs

 

[DaleH]

FWIW a F150 is a 4-stroke motor, but you say you have a 2-stoke and it appears to have an inlet manifold behind the carbs (not a throttle body) so I'm assuming you have a 2-stroke OB.

Thanks guys really hope this isnt too expensive plus I wanna fish next week.

IMHO, fuggedhabout (sp?) fishing until you get this fixed! Unless you have $10K spare change lying around … :shock: !

Seems as if the cylinder is not getting fuel.

Does it look WET at all? Otherwise, it doesn’t seem right, as if it wasn’t getting fuel it wouldn’t be getting oil, and without oil (though not firing) I’m surprised you haven’t had issues well before now.

Also since I bought the boat in 04 have not been impressed with fuel consumption and power. I know my WOT was a little low only 4600 RPMS.

Ouch! Well, now we know why ...

OK, it’s water well over the dam and down into the far, far, furthest oceans by now … so I won't beat you up anymore, but I sure hope “others” can learn from this example.

On any OB, if you aren’t turning within ~300 RPMs of the stated maximum RPMs (Spring time, new paint or newly clean hull, 2 guys 7 typical gear, maybe 1/2 fuel or so) , then (1) you have an issue like this [mechanical, fuel-related or electrical] or (2) the boat is wearing the wrong prop, or (3) you may have a linkage/adjustment problem. Any one of them can lug a motor and in severe cases cause a catastrophic failure :shock: .

… I remain absolutely amazed you’ve been running it this long!

There is fuel lines feeding what looks to be a manifold right behind the carb, is there an injector in there that may be clogged?

That’s the inlet manifold. I know tests to “check carbs while running”, but if I were you … I WOULD NOT START THAT MOTOR!

Should I run a compression test on that cylinder.

Waste of time IMHO, in due time you can and will find out if any damage as done, but comp only tells you if you lost compression, you need to isolate and find the cure NOW!

RUN, Forrest, RUN … do not walk … to your nearest Yamaha dealer or OB repair service place. Again, I myself wouldn’t start it for anyone … 2-stroke or 4-stroke OB ...to do so would be IMHO, from what you've told us, quite foolish.

 

[Megabyte]

Could yer motor be a Z-150, HPDI ?

I was thinking that too, but they don't have 'carbs'. :?: :?: :?:

 

[ultrasport]

Thanks for replys guys. Dale really? By the way my manual for 150C says 4500-5500 WOT RPM so dont try to crack jokes and yes would be within 300 RPM of WOT. I respect your knowledge and responding about my response but sounds more like you like to make fun of my problems more than help me out so do me a favor and dont charm in again.

 

[ultrasport]

150 hp 2 stroke carbed motor

 

[DaleH]

I respect your knowledge and responding about my response but sounds more like you like to make fun of my problems more than help me out so do me a favor and dont charm in again.

Not at all, sorry you took it that way. If anyone took this too lightly - you did. Your motor has a problem ... but in your own words - you'd rather go fishing. You may not like how direct I was, nor my sarcasm, but in the end ... it it were my motor, I'd fix it pronto.

 

[Bryan 2530]

I would start with compression, if the cylinder is starved for fuel then it is not getting oil. If compression is bad, your problems are deeper than clogged fuel passages at this point.

Then look at the carbs, can you drain the bowl in the carb? If so you could do that and if no fuel comes out, you may have a clogged float valve.

I am not familiar with that motor so I can't say exactly where those parts are.

Pictures might help.

Below is a generic picture of carb parts but the thing that looks like a little bullet or a pencil is the float valve, that could be clogged.
But again, no fuel = no oil and that is bad, bad ,bad.
If you were closer I would let you use my compression test kit but you should be able to find someone close to do it.

 

[gw204]

150 hp 2 stroke carbed motor

And if it is the C150, I'm pretty sure that is a premix motor. Have you been adding oil to your gas at a 50:1 ratio or do you have an external oil tank you fill up?

Step 1 is a compression test. Post your results and we'll go from there.

 

[fliboi21]

If the motor is an '04 its not a pre-mix it has a oil pump. Bryan 2530 has got it nailed. I see you are from LI, so the boat has probably been sitting for the winter. This can cause the carbs to be gunked up. The 150 carbed version has 3 sets of double barrel carbs. More than likely the cylinder that is running lean or not getting fuel/oil has a blocked/ gunked carb. The needle valve is probably stuck in the port not allowing fuel through. The good news is this is a relatively easy fix. Either rebuild the carb completly or just clean what you got. The bad news is if you have run the motor like this the cylinder can be scored and this is very bad! A compression check like everyone has said would be a good idea also. I am very familiar with this motor if you need any help or more info shoot me a PM, or might be able to help a fellow Parker owner I'm right down the road from you in northport.

 

[ultrasport]

Thanks for responses guys and fliboy for offering to help appreciate it but I just took the boat to accurate marine in Bohemia to have it professionally looked at, will post the end results.

 

[DaleH]

FWIW a coil that breaks down @ higher RPMs will also cause plugs to look the SAME as shown. And with all that raw fuel not firing, the fuel/oil mix washes the plug clean.

That's why I didn't advocate nor recommend a comp test ... yet, as while one will be done, there was a larger issue to be resolved first. That's why yhr recommendation to bring to a pro.

Not all issues for the appearance like those plugs as shown are fuel related ... . 'Nuff said here.

 

[CaptainJim]

and this still doesnt solve his RPM problem... his rpms are too low, and that motor is lugging.

 

[DaleH]

and this still doesnt solve his RPM problem... his rpms are too low, and that motor is lugging.

True, but I was thinking it could have been a dropped cylinder for ... uhhhh, longer than anyone wants to think about ... as a fuel/oil washed xcylinder will move ...

 

[ultrasport]

Carb had to be serviced, dont know all details but mechanic said that needle valves were stuck and needed replacement. I may have been running on 4 or 5 cylinders. The bad needle valve "washed" out one of the plugs causing the new looking plug. Mechanic says im good to go firing all cylinders with a dyno test. Will be hoping for good results this weekend when I drop the parker in her home. Just a lil background of situation I would never run the boat if I thought there was any problem with the motor. That would just be foolish. I bought the boat in August 2009 and since than the motor fired up every turn, never ran rough, and wot was 4600. I know a lil low. I did not imagine that I was not firing all cylinders. Lesson learned should have done a compression test upon purchase, which I know is standard. Thanks for info guys and cost for repair was $600.

 

[Parker23]

You better hope there is no problems down the road from running that motor it that condition.

 

[Bryan 2530]

Carb had to be serviced, dont know all details but mechanic said that needle valves were stuck and needed replacement.

Good news!!!!! Time to go fishin'

We had a carbed yammi 70hp that needed to be cleaned out every year to get it to run full out. This was before ethanol though, run Startron and you should be good.

 

[ultrasport]

splased boat sat good news boat had much more power about 800 rpms more than past and was able to cruise through 1 footers with 3 guys 100 gals of fuel at about 32 mph. Bad noticed a sheen behind motor, pulled engine cover and noticed a steady fuel leak coming out of the middle carb. Pulling boat in morning and bringing back to mechanic.

 

[outofcommission]

How's the motor running? I had the same problem on a 94 yami 200 carb motor and after chasing it for a whole summer and having several mechanics look at it, it turned out to just be a coil... We all did a spark test the old/dangerous way and we had spark with the plug against the head but when I finally got the right advice and tool (coil tester) it turned out the coil was weak. This was after listening to all of the wrong advice and changinging the head gaskets on both motors.... cost me a small fortune and a lot of time!!! A coil tester is about 10 bucks and you can test the spark w/out ever removing a plug and having fuel shoot out of the cylinder onto a sparking plug!!!! I'm sure your up and running by now but if the problem persists you might want to try this...

 

[ultrasport]

Motor has been running great with no issues so far.