69 55hp running Rich top end

[partsranger]

I got this boat as a fathers day gift last year. Hasn't ran right since I got it. I put plugs in it last year and set points but ran like a bag when under load, seemed like a carb prob. Runs worse once it warms up. I did the carbs and filed the points and reset. Still the same. I have however noticed that the spark seems good to me but when I pull the wires 1 at a time,the top one does nothing. Quick little burp when I put it back on but that is it. When I put my hand over carbs, bottom 2 stall engine with just a little restriction(just waving my hand past) but the top 1 I can plug. Doesn't make a difference and also doesn't have near as much suction. When I plug it, it actually blows fuel on my hand. New fuel tank and hose, bulb is hard. What would cause this? Been on this for 2 weeks - waiting for service manual to arrive.

 

[partsranger]

Re: Running rich

Re: Running rich

So I figured out the running on 2 thing. Carb linkage outta wack. Now it runs on all 3 but 1st test run bombed. Running rich bad even after re-sync carbs. At high end you can here it boggy and unresponsive. Pull the fuel line and after a couple min. when the fuel starts to run out power like no tomorrow. Chkd fuel pump diaphragm, can fuel pumps make to much pressure?
float valves and float levels seemed good to me when I cleaned the carbs? No fuel in pulse line from crankcase to pump either.

 

[R.Johnson]

Re: 69 55hp running on 2 cyl

Re: 69 55hp running on 2 cyl

Check the compression.

 

[kenmyfam]

Re: 69 55hp running on 2 cyl

Re: 69 55hp running on 2 cyl

Agree, do a basic health check on the motor. Compression and spark.

 

[partsranger]

Re: 69 55hp running on 2 cyl

Re: 69 55hp running on 2 cyl

compression 110 across, spark seems good to me, jumps a good 1/4"
runs good low end, it's when i throttle up to the point where the carb flaps start opening. It revs up but sluggish in top end and rough. When I unhook fuel pump pulse line it, it runs smoother and revs nicely, but only after it runs for 1/2 a minute to burn float bowls empty. There are no jets in these carbs that I can find, only hi-speed nozzles. The fuel flow at this point only depends on venturi vacuum, as far as I can tell. So what can make this run rich at top end? I pulled the fuel line on the lake at full throttle and after about 20 seconds it revs up and pulls nice. Also when running in a barrel I find I get a biuld up of black sludge oil/exhaust in barrel.

 

[R.Johnson]

Re: 69 55hp running on 2 cyl

Re: 69 55hp running on 2 cyl

There are high speed jet's in those carbs'. They could well need a cleaning. At the bottom of the float bowl is a hex head screw, under this, but internal where you can't see it is the jet. It takes a special screw driver to remove it. You need a manual here. Every thing has to be put back in sync. after carbs' are removed.

 

[partsranger]

Re: 69 55hp running on 2 cyl

Re: 69 55hp running on 2 cyl

Found the jets, cleaned them. Still running rich. Don't know where to go next. Nobody will work on this thing because they say to many parts are obsolete.

 

[R.Johnson]

Re: 69 55hp running on 2 cyl

Re: 69 55hp running on 2 cyl

are the carb's in sync, or opening at the same time? Is the ignition stator plate going to full advance?

 

[partsranger]

Re: 69 55hp running on 2 cyl

Re: 69 55hp running on 2 cyl

Carbs are synced but not sure how to tell timing. My manual says my outboard may or may not have timing marks on flywheel guard. I don't see any.

 

[R.Johnson]

Re: 69 55hp running Rich top end

There are timing number's on the flywheel, and a timing pointer at the top of the manifold. I did'nt mean if it is in time. Is the stator plate going up against the timing stop screw at full throttle.

 

[partsranger]

Re: 69 55hp running Rich top end

yes it is, but what is to say the timing stop is positioned correctly. Is there a spec for setting this? Can't find anything in the manual. Says I shouls be at mark at 4500 rpm, and full throttle rpm should be 5000. Kinda hard to test this stuff in the driveway I'm thinking. Even with the barrel full of water

 

[R.Johnson]

Re: 69 55hp running Rich top end

I was wrong about the timing mark's. The manual shows a raised line on the flywheel, and a raised rectangle on the ring guard. They have to be brought into agreement. You can't do this on a hose, or in a barrel. I don't see how you could use Joe Reeves method in this case. With out a test tank, and test wheel, that leaves on the boat. I never liked doing that. It always looked, and felt like a circus act to me. You will have to use a bright paint on that flywheel line, or you won't be able to see it in the sunlight, even with the brightest timing light.

 

[partsranger]

Re: 69 55hp running Rich top end

to the lake we go tomorrow after work. Only 10 min away to the reservoir. Hope it's not windy.

 

[partsranger]

Re: 69 55hp running Rich top end

can someone tell me which marks I should be using?

 

[partsranger]

Re: 69 55hp running Rich top end

can someone tell me which marks I should be using?