spittin' and spudderin'

[poolshark38759]

i have an older model Johnson (pre-1978??) that cranks and runs good til it warms up or try to run wide-open throttle...then it boggs down and will barely go..almost acts like the choke it coming on or the exhaust it clogged...when first cranked or taken out of gear you can open the throttle all way up and it will rev all the way up...any ideas on theis problem will be greatly appreciated...

 

[THE-TAZ]

Re: spittin' and spudderin'

Hey Poolshark, have the same problem with my Mariner and have read alot of other people have same problem with various motors. Alot of good knowledge here. Still haven't narrowed mine down. What part of Mississippi. Try punching in bogging down in the search and there is alot of info there.<br /><br />Taz

 

[ob]

Re: spittin' and spudderin'

poolshark,Your symptom could be one or more of several things.<br /><br />-Fouled carbs<br />-restricted exhaust ports<br />-Fuel line or filter restriction<br />-fuel line leaks<br />-Fuel tank not venting<br />-carb linkage out of adjustment<br />-fuel tank pickup restricted<br />-faulty anti-syphon valve on tank fitting<br />-failing fuel pump<br />-reed valves not seating<br /><br />Not advisable to rev engine past 2500 rpms out of gear and unloaded.Even if it would reach 6000 rpms out of gear is not an accurate indication of motors performance under load.If you are not familiar with checking out and eliminating these items as possibility of symptom I highly recommend obtaining a factory manual specific to your motor.

 

[Walker]

Re: spittin' and spudderin'

Could also be spark plugs.

 

[rickdb1boat]

Re: spittin' and spudderin'

Or overheating. See if you can hold your hand on the powerhead when this occurs to see if it's too hot.

 

[poolshark38759]

Re: spittin' and spudderin'

the spark plugs are usually black and gunky when i remove them... i can clean them up and it will do so-so for a minute...i can give a shot or two of carb cleaner and it will run better til burns the cleaner out.. what should the gap for the plugs be set at?? and where can i find a manual???

 

[papasage]

Re: spittin' and spudderin'

when my 50 hp johnson did that it was one of my carbs was not putting gas in that cylinder . the highspeed jet was clogged .or the plug was fouled . you cant hear a missing cylinder untilyou put it in the water and put preasure on it. when i have mine on a hose while idleing i will pull the plug wires off one at a time .you cantell if it is not firing . it will rev out of gear on one cylinder . my 55 evinrude was not runing on both cylinders untill i reved it up .when i pumped the primer it wouldnot git tight .gass was flowing out of the top carb .took it apare it was allright .with the carbs off with the gas line hooked up i pumped the primer bulb gass stillcame out of the enguin where the carb was bolted on guess what the fuelpumpdiafram leaking never had that probablem befor .first time foe every thing . live and learn. papasage

 

[alcan]

Re: spittin' and spudderin'

Hi Poolshark<br /> If you could post the mod# of this fine motor it would help. I looked at your profile and see a 25hp johnson as a motor you've run. I'll asume this is the one were talking about. We still won't know the year W/O mod.#. Please don't squirt or spray anything other than pre-mix fuel into the carb.Spraying carb cleaner does nothing for the carb, it just washes all the oil out of the engine. Since the engine seems to run better with a squirt of this stuff, my guess is there is a problem in the fuel system. If you need to clean your carb remove it, disassemble it, Then you can spray carb cleaner through all the holes. Manuals are available at the bottom of the page. You might find a copy at the library. I got a J.C.whitney catolog the other day they have them, Napa my have them also.

 

[poolshark38759]

Re: spittin' and spudderin'

i will try these ideas and get the model number posted asap...thanx for all your help...will let u know how i come out...

 

[poolshark38759]

Re: spittin' and spudderin'

here is the model number for my 25hp Johnson--> 25R75B serial number: E4234833... it is electric start... i am running champion J8C plugs...

 

[rickdb1boat]

Re: spittin' and spudderin'

That be a 1975 Model!<br />Oh Yeah, the Gap is .030 on the plugs.

 

[rickdb1boat]

Re: spittin' and spudderin'

poolshark38759 <br />You can get a Factory Manual at the links below or a Generic Manual at the bottom of this page.<br /><br /> Manual 1 <br /><br /> Manual 2

 

[poolshark38759]

Re: spittin' and spudderin'

getting a repair manual next sunday from a cousin who had similar problems out of a 15 hp John...his was a capcitor that was putting out insufficent voltage for the spark...when i get the manual i will start working on it..i am not to machinically inclined but can follow directions and pictures and figure it out..

 

[crazybear-uk]

Re: spittin' and spudderin'

hi <br />just a word of WARNING i would not advice pulling of one of the plug leads to see which one is not firing this engine has Cdi unit (powerpack) and using this proccess can damage the unit. something we were told in college dont know if it is stated in manual. <br />regards<br />mark

 

[poolshark38759]

Re: spittin' and spudderin'

thanks for tip crazy!!

 

[poolshark38759]

Re: spittin' and spudderin'

good news/bad news..<br /><br />was able to get out and run motor in a barrel...ran semi fine...does not get too hot to touch (can leave hand 4-5 seconds before starts to get warm)..still doesnt want to idle smooth....does for a couple of seconds then misses and repeats....water is spurting out of exhaust ports that is warm..dont see where water is peeing out of pee hole(should come out under motor and to the right of boat???) water in test barrel was really oily when i finished (8-10 min test)...<br /><br />i guess it would be the intake gasket is leaking...could see gas/oil bubbling right under flywheel on left side of motor when it would miss..plugs were extremely oily after run also...<br /><br />any ideas..<br /><br />thanx

 

[poolshark38759]

Re: spittin' and spudderin'

was able to work on motor..<br /><br />took carb off and removed the bowl and looked thru but didnt see anything looked good to me...there was a yellowish tint in bottom that would scrape off...looked kinda like cake crumbs...?????? <br /><br />know where i can get detail on the carb rebuild..my manual is a generic... <br /><br />thanx evryone for help so far...<br /><br />wish i was doing better but weather is rainy or cold...not many good hours to work

 

[poolshark38759]

Re: spittin' and spudderin'

thanx everyone for all your help....

 

[Boatist]

Re: spittin' and spudderin'

Poolshark<br />First I would do a compression check on engine. I do not think the 1975 had CDI ingition but either way I would check spark. Get a old spark plug and it does not mater what brand. Adjust gap to .045, Ground plug to power head. Move one of the spark plug wires to this plug and start motor and see if get a good spark, then shut it down and do same with other spark plug wire. While your doing the spark check note how the engine runs on other plug, this will give your big clue if one cylinder is weak.<br /><br />I would also make sure you are useing right oil mix since you got so much oil in tank, should be 50 to 1. It could be one cylinder is not fireing at all. Next I would decarb the engine.<br /><br />You said you have Champion J8C plugs. I do not belive that plug has been made for over 10 years so I would change the plugs. Need to change them anyway after do decarb.<br /><br />If you remove the Carb again make sure the float is not binding on the sides of the carb. Make sure the float actually floats in gas. With bowl off and carb up side down the float be level with the top of carb if adjusted right. Also probably a good idea to change needle valve and seat, there cheap.

 

[Gold Bear]

Re: spittin' and spudderin'

poolshark38759<br /><br />"i guess it would be the intake gasket is leaking...could see gas/oil bubbling right under flywheel on left side of motor when it would miss..plugs were extremely oily after run also..."<br /><br />This gasket leaking will affect the perfromance of your fuel pump. The fuel pump (diaphram)operates off crankcase vacume / pressure.<br /><br />There is a crankshaft seal right under the flywheel. Is that what is leaking?? Seal or gasket - you need to fix that problem then take it from there.<br /><br />Good Luck,<br /><br />Gold Bear