Johnson 87 48hp No high speed problem

[Highdog1]

Start up and idle is fine in the water but when give it more throttle it bogs down but doesn't stall out , won't go full speed. Have checked spark and all seems ok , the battery pack had proper reading other than a 6v diff on one of the cylinder than the other but was within the range it suppose to be. Stator tested fine as well, and checked and rechecked carbs, gas lines, fuel pump has been replaced recently. Pretty stumped on what's going on but recently had the water pump go out, replaced t-stat and water pump and engine did get hot and over heated but shut off immediately and compression is reading 150psi on both cylinders! Any other suggestions please? thanks

 

[rolmops]

It may be that your link&sync needs some adjustment. but in order to check if it is a carburetor problem, push on the switch or open the fuel enrichener manually while accelerating. This will supply more fuel. if that helps,you have a carburetor problem.

 

[Highdog1]

Thanks for response rolmops, got a chance to check out the linkage and carb while in the water and all checks good and rechecked the compression cold and warm and is good. The stator and trigger readings are as they should be, I"m thinking maybe power pack?? not sure about that cuz it gives me a reading on both of the orange wires as in the range it says is should be but are on the lower end. I don't know a lot about the power packs but if it puts out voltage and giving me spark on both cylinders i just assumed it's okay. It just acting like it's only running on one cylinder. Any other suggestions or something I'm overlooking? , would be appreciated.

 

[juno pierrat]

what happens when the key is pushed in while throttle advanced?

 

[lmuss53]

Pump the ball while it's at full throttle, if it picks up look to a carb or fuel pump issue, I would look to the fuel pump first. Hitting the primer won't tell you much if the pump isn't supplying fuel. Pumping the ball will give it a shot of fuel so you can see if the carb is OK.

 

[juno pierrat]

Had similar problem, would not go over 1800 but would not die, only bogg, Didn't have DVA voltmeter, measured some things, but decide to look under flywheel. Also had a weak spark, would not jump 7/16 gap, barely1/4. found charge coil had a black gooie discharge. you say you checked stator and trigger, how about the charge coil. the coil wires are the brown and brown/yellow wires going to the 5 wire plug from the p-pack. i have your same engine.

 

[rolmops]

what happens when the key is pushed in while throttle advanced?

When you push in the key,it activates the fuel enrichener. It supplies a bit more fuel to the engine.Sort of like as choke,but instead of cutting off the air supply,you increase the fuel supply. In both cases the fuel air mixture becomes richer.

 

[Highdog1]

greasmonkeyjmj highjacked the thread ... Problem not solved!!

 

[Highdog1]

When pushing the key in while throttling it up it just bogs , same with the manual choke, stalls out. Thanks for reply.

 

[GA_Boater]

It was not hijacked. It was a mis-post. Carry on.

What do you mean by "checked and rechecked the carbs"?

Do you have strong, blue spark on both cylinders? And the spark jumps about 7/16" on both? Have the plugs been changed since this all started. And did it run OK before the overheat? And the last question - A new motor to you?

 

[Highdog1]

Thanks GA Boater, jumps the gap and good blue spark. I also replaced the top ignition coil because it would run in idle really good off the bottom cylinder but the top on its own would fire up but not stay running. It ran really good before the overheat, put the water pump in and hasn't worked the same since. The boat is new to me, only had it about a month. Compression tested out good still

 

[Highdog1]

Apologies to greasemonkeyjmj if sees this, I'm new to this forum, thanks for the help.

 

[Highdog1]

Also when I purchased the boat and motor the carbs had been rebuilt. When i give it throttle it only reaches about about half throttle then just bogs out, like it just doesnt have the juice or umph to go past half throttle. Checked the throttle cable seems good. I had somebody check inside the carbs while trying to go faster but I can only get it up so high but gas is coming out of the jets. pumped the bulb no difference have new gas tank, bulb and hoses. Fuel is new as well. Carbs, linkage adjustments were working top shape prior to the water pump out/overheat.

 

[jakedaawg]

Couple simple things to try...

1. With engine off fully advance throttle in gear, check to make sure that timer base advances, also verify that throttle plates open completely.

2. Have you tried running with cover off? May be an air issue.

3. Have you verified that the arrow on the bulb points towards the motor?

 

[jakedaawg]

Couple simple things to try...

1. With engine off fully advance throttle in gear, check to make sure that timer base advances, also verify that throttle plates open completely.

2. Have you tried running with cover off? May be an air issue.

3. Have you verified that the arrow on the bulb points towards the motor?

 

[Highdog1]

Thx jakedaawg, Yes I have tried everything you have suggested. Now I noticed that my spark plugs are always WET with gas. I have the primer style choke (electric sol. valve) that blows gas into the motor just past the carbs. causing to much gas?

 

[Highdog1]

And yes, the trigger is giving a good reading in the ohms it says it should be at.

 

[Highdog1]

Well found water in both cylinders! changed 3 head gaskets, 2 heads!, and had 1-milled down, also over torque and 6 weeks later? Water .water everywhere! Took it in to sone local native's ? It took them 5 short days! but they said they had fixed the problem? Going to pick it up. More later

 

[Highdog1]

Well $%&*.00 later we took it out for a ride, Boat ran like crap! WOT! But no water in cylinders!

 

[juno pierrat]

thanks for the up date, sorry for no fix yet,what are symptoms now? with so much work on it now maybe you could give us new compression numbers, also please reread post #6, about the charge coil
also there is a cheap factory manual online ,
keep trying with good compression it got to be fuel or electrical

EDIT: Deleted link, copyright infringement. See rule #3..