Johnson 35EL78R Problems - Please help

Hi,
I recently purchased a Track V16 boat with a Johnson 35 HP electric start motor. WHen running the motor, it idles fine and then when I throttle up, there's very little power and then after a minute or so, the throttle just kicks in and winds out. I am getting about 24 mph at WOT. Does this speed seem reasonable? Boat is 16 ft, 72" beam and weights about 600 lbs + gear and motor.

Here's what I have done so far.

1. New gas tank, primer bulb and new lines from tank to primer bulb and from primer bulb to motor.

2. I just removed the spark plugs and they were pretty fouled. I haven't had the boat out yet since replacing the plugs.

3. THe choke assembly seems to be functioning properly, althought when chocked, the valve is not completely closed, but pretty close.

As anyone seen this issue? I have been researching this tonight and it sounds like it could be a dirty carb, power pack etc.

Any help would be great.
Thanks,
Greg

Re: Johnson 35EL78R Problems - Please help

First you need to do the three main checks.
Compression, fuel and spark.
Get those results and more people can help you out.
I had a similar problem with my old 70hp Johnny and it turned out to be dirty carbs and fuel filter.
Cleaned them up two times and now she runs great!


Here is a link to my thread with some great info
http://forums.iboats.com/showthread.php?t=402604
Good-luck!

Re: Johnson 35EL78R Problems - Please help

Thanks for the tips. I am going to get a compression gauge tomorrow. One question, can I rebuild the carb myself? Is it very difficult? I am pretty mechanically inclined. In looking at it, it looks like there are 3 bolts holding it on. The linkages seem to be the area that I would be most concerned about. I was planning on taking digital pictures before removing. Also, how long do you soak the carb? I have heard 1 hour and I have heard 24 hours?

Thanks for the help.
Greg

Re: Johnson 35EL78R Problems - Please help

Well I soaked mine for 30mins - 1hr and compressed air through the jets (the little hollow needles) and it worked fine for me but my carbs were somewhat clean.
You should be able to do it on your own.
Good luck and keep us updated

Re: Johnson 35EL78R Problems - Please help

pay particular attention to the linkage from the carb to the timing plate...at start and at wot...if you'll go to shop2.evinrude.com...select..johnson...then 1978..35hp..your model no...you'll find diagrams of all components...the timing plate cam I'm referring to is #34 under magneto...the carb diagram may help you on reassembly as well