97 force 75 wont start unless throttle wide open and cranks for too long

alweb57

Recruit
Joined
Aug 13, 2014
Messages
2
i installed new plugs and wires , fuel filter . Also new fuel line from tank. once it starts it seems to run fine, any advice would be helpful
 

Jiggz

Captain
Joined
Oct 23, 2009
Messages
3,817
Double check the carb's idle mixture screws are set properly, 1~1 1/2 turn out from slightly seated. Then double check the floats to make sure they are not stuck in the up position. While in there, clean them and the needles with carb cleaner. If problem persists, you need to check for spark on all cylinders. Or when it is running check to make sure none of the carbs is blowing back indicating faulty reeds.
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,657
Welcome to iboats alweb57.


Is this boat new to you?
Is this a new problem that just popped up?

Are you using the "choke".

Review your starting procedure and compare to this one:



Open fuel tank vent

Check the kill switch, place in "run" position

Squeeze fuel primer bulb till firm.

Advance the throttle 3/4 way or more , without putting it in gear. -- This is done by either pushing a button in the center of the controls, or pulling the shift handle toward the driver, or raising the fast idle lever, all depending on what control unit you have.

Turn the key to the on/run position.

Activate the choke (fuel enrichment valve) by pushing in on the key. The valve is only open while the key is being pushed in.

Turn the key to start while continuing to hold the key in.

Release the key and choke when it starts.

3-5 seconds of "choke", is usually enough.

Be ready to pull the throttle back toward the idle/neutral position, when the engine starts and the revs increase.

Continue to pull the throttle back as the engine warms up.

You should not have to use the choke much, if at all, once the engine has warmed up.

Engine should start within 10 seconds of turning the key.
 

MickLovin

Master Chief Petty Officer
Joined
Feb 18, 2013
Messages
822
Compression, spark and fuel, check them in that order, but as Roscoe mentions, do you choke it first start?
Easy check for spark is while you get it running, pull one spark plug lead off at a time and see if you notice any difference in how it runs.
With good compression, spark and fuel it should start up with choke alone and no throttle.
 

alweb57

Recruit
Joined
Aug 13, 2014
Messages
2
thankyou for your responses
yes this boat and engine is new to me
i will be using all the advice this weekend
i will post my results

one question is : how do i know if the fuel enrichment valve is operating
thanks
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,657
You would have to pull the fuel line off of the valve, then have someone push in the key while you listen for a click, and watch to see if the valve opens and fuel flows out.
 
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