Begging...help on 73' Johnson 65 HP.

[imported_KLR]

I need some advice as I am new to boats and outboards. If anyone could point me in the right direction I would SOOOO appreciate it.

-- please forgive terminology mistakes, Im learning --

From the beginning.....
I just bought a 1973 Thunderbird Trihull with a 1973 Johnson 65 HP outboard (original engine?)

Engine's history as I know it......
Last owner used the boat quite alot and had trouble last fall with the cooling system. He found out on the lower drive part of the outboard there is a tube (about 3/4" x 4") that I assume routes the water from the inlets up to the engine(?) had come loose and water was leaking into the lower drive unit and there was a loss of cooling, the engine suffered damage to #2 cyl.

A marine shop did the repairs last October which included.....
Bored cylinders .020 over and rebuilt the whole head unit,
rebuilt the carbs,
tuned the whole engine,
checked the ingnition system, fuel system & everything else.

The boat ran BEAUTIFUL for 4 months till the lower unit went out one day and the boat lost forward & reverse.

The lower unit was replaced and now I bought the boat and cant get it to start.

It will fire up soon as you hit the key but dies in about 3 sec.
If I stay at the engine while someone cranks it and play with the choke & hold the throttle about 1/2 way open it will start and run rough for about 20-30 sec. It appears to be flooding real bad and gas does run out the opening of the caburators. When it does start and run for the 20 seconds it bogs bad and barely runs till it dies.
I thought the floats might be bad or adjusted wrong but they were new and set right. I ran a compression test today and all 3 cyl were EXACTLY 100psi.

Timing is perfect
compression is good
spark is good
carbs are SUPER clean & float is set right
fuel pressure is good

What am I missing?
What would make the carbs leak gas out of the venturis?

Any help would be appreciated

Mike

 

[billfranki]

Re: Begging...help on 73' Johnson 65 HP.

I had very similar symptoms on my '65 Evinrude Starflite-90. My problem turned out to be my carb's low speed idle setting was out of adjuslment.

To check this, you'll need to find proper service documentation, either the specific service manual or a third party manual from Clymer or Seloc and look up the procedure. Usually it's pretty simple to set the adjustment by gently closing (fully seating) the valve screw and then backing it off by a prescribed amount (3/4 turn, for example). This will get you to a base setting that may eliminate the problem without further adjustment. The service doc will also include a procedure to optimize this adjustment.

Good luck!

-Bill

 

[tashasdaddy]

Re: Begging...help on 73' Johnson 65 HP.

check out the post : Joe Reeve can you post your slow peed idle set" gives you all the directions there are 2 sets 1 for slow only and 2 for slow and fast.

 

[imported_KLR]

Re: Begging...help on 73' Johnson 65 HP.

As I understand it there isnt any needles to adjust. This carb has the low speed orafice & high speed orafice, thats all. I know of no way to adjust them.

I have never had an engine that had good compression, fuel, good spark and perfect timing that just wouldnt start.

NOW, on top of that problem it wouldnt crank over today. I checked every fuse I could find and they were all good. I am getting very frustrated with this boat. I just bought it and now I cant get it running.
I have an appointment Friday to take it to a marine mechanic but had hoped to get it running myself..oh well.