Motor screwed up again

[andy capp]

Now my money for the mouille festival will be spent towards fixing it. I took it out a couple weeks ago and it would barely plane out, The boat usually runs about 36-38mph on the gps, I changed the plugs thinking that was the problem and it is still the same . I checked it and have strong spark in all 3 cylinders. But the bottom plug looked like I just put it in. I did just put them in but the other had a little color to them. My assumption is that I am not getting any fuel to the 3rd cylinder. The plug wasnt even wet. And didnt smell like gas. Any one else think of any other problem it could be?

[Burksee]

I'm assuming its a 3 cylinder outboard? What make and size is it? Does it have 1 or 3 carbs/fuel pump(s)? If its got three carbs check flow to the carb. You might want to do a compression test. Being a "end" cylinder you might have a crank seal failure thats letting air into the cylinder instead of gas/air mix. Lots of possibilitys at this point!

[andy capp]

Its a 3 cyl. 1976 70 hp johnson triple carbs.

[Burksee]

AC,

If you've got spark and the spark plug is dry it sounds like you've got a plugged fuel line and/or carb. Tondga may be better to answer this one but I'm thinking you've got one fuel pump that feeds all three carbs. I'd pull the line off the carb see if there's fuel getting to it, if so take the carb off and check for restrictions/dirt in the carb. inlet needle/float area.

[andy capp]

I think your right. The problem is i'm not that mechanically incline to do it. I just got quoted $350. To perform inspection and have all three carbs rebuilt.

[higherpowered]

Are you sure you're getting spark at that cylinder? I've got a 1975 85HP Evinrude (4 cyl/2 carbs) that was showing much the same symptom. I thought it was fuel delivery too. Turned out to be just the number 3 cylinder at the power pack was bad. Easy enough job, just the $150 ding in the wallet that hurt.

[andy capp]

Positive its been looked at. Fuel delivery is the problem. $ 350 to have them rebuilt and synched.

[higherpowered]

I rebuilt the two carbs on mine myself. Never did a carb before and I won't say it was fun getting 'em off, but I've got the manual and if you want to borrow it and give it a shot let me know. The rebuild kit's will probably run you $100, but that would still leave you with $250 in your pocket. If your interested let me know. I'll verify your engine is in the book, but I'm almost certain it is.

[andy capp]

I found carb kits on the net at $24 a piece. My friend has a manual also. Thanks for offering I'll keep you in mind.

[ESOX]

Verify that the lower carb throttle plate is opening in sync with the other ones before getting into a rebuild. Could just be that the rod came loose.

[TONGA]

yea make sure it is opening ,,,those little plastic snaps that hold all those linkage bars together do let go from time to time,,,sometimes they will also fall off the choke and let it fall shut on one carb,,,
for the fuel problem,,let see you have a fuel line that feeds one carb from the pump,,then the carbs are just daisy chained together,,,so if you are not getting gas to one carb then more than likely you just have a stuck needle and float,,,if you can tell for sure it is not getting gas then you can ,well most of the time anyway,,give the fuel bowl a few sharp taps with the hadle of a screwdriver and she should un-stick and fill up
Don't drop that $350 just yet,,it's doubtfull that you need your carbs rebuilt
How far from Fair Haven are you?
buy the way the best way to tell if the carb is full is to take a 7/16 wrench (never mind the slot for the screwdriver) and pull the plug on the fuel bowl,,,it's at the bottom of the carb right in front!

[andy capp]

Tonga I'm noy too far from fairhaven. I bought your little 12 footer last winter. I did compresion checks like I was told and the compression is good. I need to pull off the front air cover so I can access the carbs. You say tap the bowl with a screwdriver? I'm supprised that towing it wouldn't unstick it. I will pull the plug for the bowl tonight.

[TONGA]

I'm kinda surprised that did not unstick her to!
if you get in over your head you can always tow her out so I can have a look see!
anyway have a look and see if she is getting fuel and let me know

[andy capp]

No fuel in bowl! I ended up pulling the carb off and the bowl. The little float plunger was stuck up. I touched it with a screwdriver and it came free. Sprayed a bunch of cleaner through it and put it back on. Fuel good now. Am I going to have to do any adjustments to the carb now that I took it off? Also the other scary part is that the motor ran for about 10 minutes with the problem. The compression is 105 in that cylinder, do you think I messed it up by running it with no fuel? No fuel = no oil.

[TONGA]

if she still has 105 she will probably be fine,I bet the rest are between 110 and 115,,,as for the carb the only thing is you need to make sure the butterflys all oppen together in sync,,,since you did not change anything else and you did not take off the other carbs you can just set it to the other carbs and you should be fine,,so what I am saying is as long as you don't mess with the other carbs your throtle position/timming advance should be fine .
in fact as long as you did not mess with the screw on the dog ear of the carb you took off you should be abile to put her back on snap the linkage in and go! just after you put her back together check to see that all 3 butterflys start to open at exactly the same time!! if not give me a shout and we will get you hooked up
but I bet she is just fine now! not only that, it sounds like you got off for a little under that $350

[andy capp]

Thanks so much tonga! I dont know what this site would do without you. Next time I co me out that way ( which will probly be for ice fishin ) I'll bring ya another 6 pack. The other cylinders compression are 111 in the middle and 120 in the top.

[TONGA]

Andy have you ever or when was the last time you did a De-Carb to that motor? if not in a while or ever, then you may want to,,,the lower cyl's always seem to get choked up first in those triple's,,so if you do a de-carb you may get those other 2 jugs numbers up near that 120 like the top jug!

[andy capp]

I've only owned the motor for 3 years. I know the original owner and the motor was overhauled about 10 years ago. The motor sat for 2 years before I bought it. I took it out last night and it runs like a champ. But TONGA you are right I should probly look into it a little further.

[TONGA]

Glad to hear she is running good,,,you may still want to run a De-Carb,,,,,,the worst thing that can happen is nothing and you are out the cost of the can,,,but I bet she will run even better!

[andy capp]

I am going to take the other 2 carbs off and clean them. I may get 40 mph out of it! I ran like a dream today. I am actually a little faster than my buddy. Last year we were dead even. TONGA i still know where you live. I will drop beer on your porch next time i am out there. We will do a little outing next year on the ice!

[andy capp]

Maybe I will bring the boat up this October and you can show me where the perch are.

[TONGA]

sounds like a plan!