surging between 2/3 and full throttle, Gave up went to the shop.

[tashasdaddy]

2006 Johnson 50, i'm suppose to know this, carbs rebuilt, adjusted, vro pump, replaced with block mount pump for this size motor. pumping bulb makes no difference. link n sinc is correct. new hose 6months old, tried 2 different tanks, found one leak, corrected. it is like fuel starvation.

what am i missing?????

 

[Randybeall]

Re: surging between 3/2 and full throttle

Re: surging between 3/2 and full throttle

Wow, I am impressed that you get 3/2 throttle opening, kind of like warp drive ........ On a more serious note, have you checked for intake track air leaks? Could you have a bad connection in the on engine electrics?

 

[tashasdaddy]

Re: surging between 3/2 and full throttle

Re: surging between 3/2 and full throttle

thanks, Randy i fixed it.

 

[jonesg]

Re: surging between 3/2 and full throttle

Re: surging between 3/2 and full throttle

Surging is usually an air leak or fuel restriction,
I might try tracing it down by installing new plugs and reading them after a run, otherwise I'd ask YOU.
Sometimes air leaks can be traced by spraying ether around connections with a straw hose.

 

[tashasdaddy]

Re: surging between 3/2 and full throttle

Re: surging between 3/2 and full throttle

new plugs, this is just the second run with this motor.

 

[mthieme]

Re: surging between 3/2 and full throttle

Re: surging between 3/2 and full throttle

Surging is usually an air leak or fuel restriction,
I might try tracing it down by installing new plugs and reading them after a run, otherwise I'd ask YOU.
Sometimes air leaks can be traced by spraying ether around connections with a straw hose.

Good point. I found an air leak (unintentionally) once on my Merc 35. It was the little round disc on the side to access the interior drillings. Although the symptoms showed up at idle.

 

[tashasdaddy]

Re: surging between 3/2 and full throttle

Re: surging between 3/2 and full throttle

great spark, to plug burning dirtier than bottom. compression 150 both cylinders.

 

[Chinewalker]

Re: surging between 3/2 and full throttle

Re: surging between 3/2 and full throttle

The butterfly valve shafts aren't loose in their bushings are they? Carbs were rebuilt - floats set as per spec? Needle retainer springs in place? Primer choke isn't feeding excess fuel, is it? I'd pull the carb covers and watch when it's running. Try putting your hand or a rag over the carb throats when it's doing its thing and see what happens...
- Scott

 

[tashasdaddy]

Re: surging between 3/2 and full throttle

Re: surging between 3/2 and full throttle

shafts fine, carbs clean rebuilt, floats set and checked, springs there, primer fine, floods when inlet blocked, butterflies level at wot. spark perfect, compression 150. fuel brand new. only one connection left for leak, and that is at the tank, did away with quick connect at motor, went straight to fuel pump.

i have found some, what i consider, excess play in the control cable.

going to do Joe Reeves wot timing this morning.

 

[youknowme]

Re: surging between 2/3 and full throttle

Re: surging between 2/3 and full throttle

2006 Johnson 50, i'm suppose to know this, carbs rebuilt, adjusted, vro pump, replaced with block mount pump for this size motor. pumping bulb makes no difference. link n sinc is correct. new hose 6months old, tried 2 different tanks, found one leak, corrected. it is like fuel starvation.

what am i missing?????

Surging" Im taking that as when you hit 2/3rd's you aint gettin the power you should?? I had a problem with my 1997'' evinrude 15 HP was on full throtle n was going NO WERE . I then cleaned my wires that come from power pac that connect to the coil(s) there was a build up of crap there so i sanded them back to copper. All was well.

 

[tashasdaddy]

Re: surging between 2/3 and full throttle

Re: surging between 2/3 and full throttle

that is good also. timing was messed up, still working now can't get to idle, just killed battery, will be back in a little while.

 

[tashasdaddy]

Re: surging between 2/3 and full throttle

Re: surging between 2/3 and full throttle

worked on it all days, exhausted my resources, took it to the shop, hopefully they can get it right, by Friday. the first one to ever beat me.

 

[iwombat]

Re: surging between 2/3 and full throttle, Gave up went to the shop.

You can sometimes find manifold leaks by squirting premix around the carb while running. If it picks, up you've found a problem. Not so common in outboards, but boy is that a useful technique in bikes.

 

[tashasdaddy]

Re: surging between 2/3 and full throttle, Gave up went to the shop.

i have no idea what the previous owner did, i've done timing, link n sinc, redid fuel lines, carbs again, you name it i did it. now won't idle long enough to shift into gear. we'll, see what Jeff says at the shop.

 

[iwombat]

Re: surging between 2/3 and full throttle, Gave up went to the shop.

Sometimes they just need to harvest blood from two sets of knuckles before a proper sacrifice to the outboard god has been made. You gotta hate when that happens.

 

[Tim Frank]

Re: surging between 2/3 and full throttle, Gave up went to the shop.

TD, I notice that it's a 2006, and first one ever to win against you.
Is it the newest that you've tackled?
They aren;t getting easier with all the electronics that are getting crammed in these days.

I suspect that Bill Gates is probably at the root of this somehow.

 

[jbjennings]

Re: surging between 2/3 and full throttle, Gave up went to the shop.

I'm going to guess a weak or intermittent coil.
Good luck and I hope your pocket doesn't get too light!
JBJ

 

[tashasdaddy]

Re: surging between 2/3 and full throttle, Gave up went to the shop.

JB, me too, yes it is the newest i've ever tackled. it is not like it is electrical, more like starving for fuel. it has me totally baffled. and of course i have the OEM manual.

 

[Tim Frank]

Re: surging between 2/3 and full throttle, Gave up went to the shop.

Don't the new ones have a fuel cut off solenoid? wonder if those can go wonky and what symptoms would show?

When you say surges from 2/3 to WOT do you mean you only get surging in that range or that when it surges it goes from 2/3 to full throttle?

FWIW the two fuel problems that were the nastiest for me to find were :
1) Erratic revs above 1/2 throttle.....I had replaced the fuel pump and internal fuel lines but did not know about a spring in the vacuum line to CCase. Hose was colla[psing. Bought the manual after that
2) After I rebuilt all carbs opened up to WOT ran beautifully and then revs would drop off then cut back in. Figured fuel, opened carbs back up one at a time. Found a fly in the float bowl of first one. (got lucky, at least luckier than the fly )

 

[seaswirl71]

Re: surging between 2/3 and full throttle, Gave up went to the shop.

I know this thread is old but what was the outcome