1975 johson 115hp no wide open throttle

[tobefree]

Can some one helpi have my throttle cable disconnected at the motor and gear in nuetral when i move the throttle to wot the timing advance hits the timing stop adjuster but throttle are barely open.motor calls for 24 degree and shows 20 degrees when i check with timing light but the throttle lever wont move any further to open the carbs up.motor starts fine and idles nice,start lever works good. help

 

[bustermin]

Re: 1975 johson 115hp no wide open throttle

WOT in neutral is not the same as when in gear. It is a safety stop to avoid over-reving the engine while in neutral. Im sure somebody will correct me if this motor does not have this function.

 

[Joe Reeves]

Re: 1975 johson 115hp no wide open throttle

Bustermin.... You are correct.

To have a engine in neutral, then open the throttle to its full rpm function, is like pulling the pin on a grenade, then laying it on the ground in front of you to see if it actually does take 7 seconds to explode.

A engine free wheeling at 5000/6000 rpm is inviting a runaway engine. By the time one figures out how to stop it, connecting rods will be flying out the side of the crankcase.

 

[tobefree]

Re: 1975 johson 115hp no wide open throttle

im checking this with the motor no running,moving the throttle lever by hand at the engine with cable disconnected the carbs wont open fully even if the gear lever is foward,but the carbs open and close freely by hand.

 

[tobefree]

Re: 1975 johson 115hp no wide open throttle

WOT in neutral is not the same as when in gear. It is a safety stop to avoid over-reving the engine while in neutral. Im sure somebody will correct me if this motor does not have this function.

even if the gear lever is in foward position without the motor running the carbs wont open fully, the advance timing stop ,stops the throttle lever from moving

 

[Joe Reeves]

Re: 1975 johson 115hp no wide open throttle

It doesn't matter if the engine is running or not, the throttle butterflies on that 1975 115hp model should open fully. Sounds like the syncronization is wrong.

The throttle butterflies should just start to open when the scribe mark on the cam is aligned dead center with the throttle cam roller. Is this set as it should be? Also, that roller should be roughly about 3/8" in diameter. Is it?

 

[tobefree]

Re: 1975 johson 115hp no wide open throttle

It doesn't matter if the engine is running or not, the throttle butterflies on that 1975 115hp model should open fully. Sounds like the syncronization is wrong.

The throttle butterflies should just start to open when the scribe mark on the cam is aligned dead center with the throttle cam roller. Is this set as it should be? Also, that roller should be roughly about 3/8" in diameter. Is it?

the carbs start to open on the mark and stops at the next mark further down thats where my timing advance hits the stop screw and the the throttle lever wont move any further.

 

[Joe Reeves]

Re: 1975 johson 115hp no wide open throttle

Pertaining to the vertical throttle lever..... the bottom portion is connected to the throttle cable, the top portion connects to the timer base.

The vertical throttle lever is a two piece component with a fairly large spring within it. When the timer base reaches its limit (up against the spark advance stop screw cap), that's when the lower portion of the vertical throttle lever would continue to move (against that spring) to force the throttle butterflies open.

Sounds like you have something jammed, frozen, adjusted wrong, something of that nature.