1997 75 hp carb adjust question

[jerryjerry05]

Re: 1997 75 hp carb adjust question

Get a FACTORY manual.Profile??You might be close to someone who can help.Start with a compression/spark tests.
That rod is for initial set up.The towershaft is for adjusting the idle.Go the begining of the Force section and do the linc and sinc by FrankA.
Turn the air screws GENTLY in to the bottom and out 1 and 1/16th out.Then leave them.
The idle is 750-800 in gear and motor warm in the water.
The holes in the side of the carb is for overflow when the needles sticks or the floats stick.
The more stuff you put in the fuel line the harder it's gonna be to get fuel to the carbs.I run a straight hose NO CONNECTORS.
When you squeeze the bulb and the diaphram is good and the floats aren't stuck it should pump up and stay firm.Not firm then figure out what's wrong.
After you start the ball should go soft as the pressure is relieved.Then the pump should take over and supply all the fuel.The bulb is just for inital fuel supply to the carb.J

 

[danb303]

Re: 1997 75 hp carb adjust question

It pumps up to firm but I wouldn't say it gets real tight. I haven't checked to see if it stays firm. I'll check it today.

Also going to try to correct my linkage adjustment. I have noticed that the flapper opens PAST horizontal. it causes it to bog a little at WOT. I usually just pull it back a bit

 

[danb303]

Re: 1997 75 hp carb adjust question

OK, I carried the boat over to the lake today and went thru the carb adjustment procedure and corrected the idle adjustment. I cut it off and put the cowl back on for a test drive. Untied it and cranked it back up... Then it went dead. Cranked it back and it went dead again. I pulled the cowl back off and it was full of smoke. I am now thinking that my exhaust tube gasket is leaking exhaust gases back up into the cowl.

any thoughts?

 

[kywings]

Re: 1997 75 hp carb adjust question

If ya'll don't mind I'd like to get in on this thread. I'm running a 75 force 1998 with very similar issues. Last week kept stalling even at 3000 rpm. When I pulled the cowl I found the middle spark plug wire boot cut (may of been hit with the cowl) and the center plug so loose oil was all around. Fixed the boot and just bought new plugs. Then very hard to start and ran but then would not idle or stall in gear at slow speeds. This week I rebuilt the fuel pump. Noticed paint on the diaphragms so I'm thinking this is the first time. One of the Check valves in the fuel pump was chewed up and the outside diaphragm had fuel on both sides. Started up at the dock and still started the same but ran and idled awesome. So much so I let it idle a while and sat on the dock and watched. When I tilted the motor back to run it away from the dock it missed and stalled. I took it for a run and it ran ok for about 1/4 mile then died. Primed it and it ran back to the dock. I replaced the fuel filter for kicks with one from Napa and it was clear. I could see air so I bled the air and restarted. Ran away from the dock and took off great and then died. I put the old filter back on since I was thinking the Napa one was not allowing enough fuel and also found the fitting from the engine to the fuel pump was loose so I thought I could be loosing vacuum. Now it runs and is back to where it was. Misses at idle and will stall. However I would like to think it runs smoother at higher speeds and I'm able to run at slow speeds now without stalling. The strange thing is in neutral,(throttle fwd) I can set it at 1200 rpms with the throttle and it purrs. Pull back the throttle to center and it drops to 1000 for a few seconds and then drops to 800 then lower and stalls when it misses. Tomorrow I'm going to try tuning the carb per the sticky. It does run well at higher speeds so I'm starting with the fuel system.

TwoFish, you said something about an incorrect breather tube. could you elaborate? And I can pump the primer till it gets relatively hard but can see fuel leak from a small hole on the right side of the carb. Does that mean anything?

 

[TwoFish]

Re: 1997 75 hp carb adjust question

Hi kywings

The short answer is Yes & Yes but you will need to start another thread. It gets a bit confusing sorting out two people?s problems in the one thread. I did the same thing when I started on this forum. People here are very good to deal with and will help you sort out the problem.

 

[kywings]

Re: 1997 75 hp carb adjust question

Will do