My 115 hp Evinrude on jet will only go about 10mph....Please tell me why?

[Huntleybill]

I have a 1995 Four Winns 14" with an evinrude 115 v4 on a jet. I'm not sure I have a jet problem or an engine problem. This is the dilemma: It starts fine, idles fine but when accelerating to WOT, it gets to about 5-10 mph only. The motor does not seem like it is at full throttle.

This is what I have done so far. I replaced the spark plugs as I thought it might be bad gas as the boat has been sitting for over a year. Along with that, I took my 6 gallon mixed fuel from my other boat as it has fresh gas/oil mix. I hooked that directly to the fuel line in the boat bypassing the boats tank and primer diaphragm. ( VRO has been disconnected previously).

I took the boat back out and it does exactly the same thing...the get up and go got up and went!! In each instance we drove around for at least 30 min. There was no over heating alarms. This boat is new to me so I don't have any history on it. Why won't it go faster?

Here is a youtube video of the engine running on the lake. My phone camera is a piece of crap so you may not be able to tell anything from it.

http://www.youtube.com/watch?v=uNqgdZt_QW8

Any suggestions would be appreciated.
Thank you
Bill

 

[Big Bubba]

Re: My 115 hp Evinrude on jet will only go about 10mph....Please tell me why?

Huntley bill,
You need to remove the engine cowling or engine cover and take the front black carbuerator cover plate off and with the engine not running advance the throttle on the remote control to wide open throttle and look down the carb throats and see if the butterflies are horizontal and also look at the timing advance arm that moves underneath the flywheel and see if it is moving its full travel and is stopping against the black rubber stopper at full throttle position or wide open throttle. What I want to see if the carb butterflies are opening to full open position or full horizontal position and the timing advance arm under the flywheel is moving full movement when the throttle is placed in wide open throttle. Let us know if it is working or not or if your having a throttle shift cable issue.

 

[Huntleybill]

Re: My 115 hp Evinrude on jet will only go about 10mph....Please tell me why?

Thank you Bubba. Here is what I could do so far. I took a picture of of the lever under the flywheel at WOT. It appears to stop just short of a bolt head that may be the stop position for the plate. There is no rubber stop that I saw...maybe it fell off. Either case, it looks like a gap of about 1/4". Not sure if that makes a big deal or not.



This motor is in a Four Winns boat and the way the motor sits in the boat it is difficult to remove the cover from the carburetors and look down the throat at the butterflies. However, with the throttle set to wide open, I can reach in and continue to rotate the shafts for the butterflies. So, I think.....and by no means take my thinking as gospel... it looks like the carb throttle is not opening all the way but in the Service Manual, it states that the shaft should only turn until the roll pins are vertical and NO FURTHER and it does exactly that. When I was out on the lake, I physically pushed those shafts open further but got little response from the engine when I did it,

If I really need to physically see the butterflies, I can try using a mirror and let you know what I found. Also, the plate the the remote control connects to seems to be traveling its full length as it goes all the way back to the stops.

I also checked spark and compression. I get a hot, strong spark on all 4 cylinders. I get compression of 120 on 3 and 105 on the 4th. I squirted some oil in that calendar, and then got 120. Now I'm scared to death this motor is #$%ed!!