evinrude 25hp jerky throttle at speed??

[Commando C2]

my 1985 25hp Evinrude 2cylinder 2 stroke is a bit difficult to gradually reduce speed .
It accelerates very well but when trying to gently reduce speed to match the speed of waves as i come down the face of them nothing happens as i decelerate then suddenly the power drops right off and i have to crank it back on quickly.

it makes slowing gently very tricky and this is vital for where i use it.
(on a tidal river wave/bore, where getting through the after waves/swell requires fine adjustments in speed)

It starts first pull and runs allday no probs. Doesnt like trawling at low speeds but i am told that is normal for this engine.

Just wondering if there are any things i can adjust, a friend mentioned the float height in the carb?

thoughts??

thanks

 

[Cofe]

Re: evinrude 25hp jerky throttle at speed??

Sounds like the throttle cable or motor linkage is binding somewhere.
With the motor off, and the cover removed, place in forward gear. Test the motor throttle control to WOT and back down again. Look at where the binding could be. If this is a tiller handle, the dogs inside the handle may need cleaned and lubed with silicone spray. The dogs ride in a curved path inside a plastic housing. Sometimes that housing gets damaged. Hope this helps ya.

 

[Commando C2]

Re: evinrude 25hp jerky throttle at speed??

thanks for that will look into the throttle housing.
it accelerates ok but then most of the time i crank it straight up.
would the air mixture screw make alot of difference here or is it mainly for low speed idling?

thanks

 

[Cofe]

Re: evinrude 25hp jerky throttle at speed??

The needle valve is used to adjust flow for a smooth idle mixture. You're throttle cable may be wore, causing it to bind. Check out the tiller control, it is a good place to start. Good luck.

 

[tashasdaddy]

Re: evinrude 25hp jerky throttle at speed??

link n sinc.

 

[Commando C2]

Re: evinrude 25hp jerky throttle at speed??

checked the throttle from the tiller to the carb and it moves the butterfly valve when the twist grip is turned.
Maybe its a jets thing or the engines are like that just because the way the carbs are made??