Mercury 1150 car tuning problem

[ippielb]

Giving the 1150 a tune up, and doing the link and sync. The boat smokes like crazy, and leaves quite the residue in the water. It’s very unappealing and I do not enjoy it. So that’s why I’m trying to tune it up, reading through the instructions on the forum here. But wandered around to other people’s threads and noticed their timing marks are totally different then mine.

this is my first time tuning the boat with this so I’ve never come across the issue before. I verified TDC on cylinder 1 lines up with the mark on the flywheel and the paper markings on the housing.

i went along with the instructions and a video done by cturboaddict on YouTube which helped tremendously to understand the terminology and visualize what was going on.

anyways, went through set the timing and the stops like dr.frankenmerc told cturboaddict to do, since I didn’t have anyone to help me turn over the engine so I could use my timing light.

all is fine and dandy until I get to the idling, I cannot for the life of me get the motor to idle. Adjusting the idle mixture screws the top carb when I screw the screw in it slightly goes down in RPM until it stumbles. So I back it off half a turn, then I go to the middle carb and when I screw the screw in the RPM greatly increases. Until it falls completely on its face and then I back off the screw half a turn, and then rpm stays way up there. The lowest carb I adjust and it does the same as the top carb slowly drops rpm a little and then starts to stumble so back half turn. The middle carb is the odd one out.

Why does it increase the rpm? I suspect a vacuum leak, so I sprayed brake clean around the mating surface and the engine bogs hard and stalls... ok, so I spray it around the mating surface of the lowest carb and it bogs hard and dies too... I don’t think it’s the mating surface that’s leaking, I feel it’s the vertical shafts that run through the butterflies connected by the plastic. Because there’s always a fuel drop on them.

Just wanted a little more experience to lend a hand on this one before I go through the not fun task of pulling the carbs on this motor.

 

[ippielb]

Also,I did a compression check and all 6 cylinders are 130-120psi. Engine ran fine above idle before this, but how much it dirties the water so fast it’s not good. And the amount of smoke is ridiculous, it’s 50:1 ratio and my sled that is 32:1 doesn’t smoke anywhere near this.

 

[Chris1956]

OK, it looks like you have an early 70's motor, with distributor ignition.

You can easily set the timing by yourself. Remove the prop and spark plugs 2-6 and install them into their wires and ground their bases.

Turn ignition on. Put timing light on #1 spark plug wire. Advance throttle in gear until carbs are about to open, but still closed.

Jumper starter solenoid to crank motor, and read timing light. It should show 4-6* BTDC. If it needs to be adjusted, you will need to loosen the 2 set screws on the brass collar about 1/2 way up distributor. They use a 5/16" wrench.

Advance throttle fully. Crank motor and read timing light. Max spark advance should be 21* BTDC. The set screw above the distributor will set max timing,.

 

[ippielb]

Well, I decided to pull the carbs and check for anything that wouldn’t promote a healthy tune. I remember how much I didn’t like pulling them off the first time I rebuilt them. So far it’s just little junk before the fuel filter screens, nothing in the bowls, nothing in the jets, but I’ve also only opened one carb so far and that was the bottom one.

I’ll finish up and check the timing that way.

 

[ippielb]

While I had the carbs apart I set the floats to proper heights, assembled it all. But didn’t have time to check timing. Heading out to the lake without it to get some more of it ready for the summer. We haven’t really had any nice days except today. Tomorrow I will check timing it will be too late to do it tonight.

 

[achris]

Lots of smoke and poor idle could also be the oil you're using. I've had more than one engine bought to me as 'will not run'. Used the customer's fuel tank and sure enough, 'will not run'. Drained the carbs, then supplied with our 'shop tank', and the engine ran perfectly. Switch back to the customer's tank, engine dies (once the fuel in the carbs and line was used from the shop tank.. And on quizzing the customer, he's just started using a different brand of oil. What brand of oil are you using?

Chris.......

 

[ippielb]

I am using ipone 2 stroke oil. I could try running different fuel. I’ll check timing tomorrow and then see how it goes.

While cleaning my carbs I did verify that the shaft that the butterfly screwed onto does in fact leak. I sprayed brake clean in the carb and let it rest against the butterfly and sure enough there was drops of it coming out the bottom.

is that normal?

 

[racerone]

Normal for them to drip a little bit at idle.-------Check fuel pump diaphragm for rupture / tears.

 

[Chris1956]

Fuel will only drip from butterfly shafts, if it is in liquid form in the carb throat. There should not be a lot of that. If you have a steady drip, it is likely the carbs are overflowing.

If that continues, rebuild the carbs with new gaskets, floats and inlet needles and seats.

I disagree with Chris. A different brand of 2 cycle oil, when mixed at 50::1, should not cause a lot different amount of smoke. Definitely check fuel pump diagram for tear or leakage past the gaskets. That will cause lots of smoke.

 

[achris]

...I disagree with Chris. A different brand of 2 cycle oil, when mixed at 50::1, should not cause a lot different amount of smoke.....

Disagree all you like. When I had my boat shop, my business partner and I could pick, with a good degree of accuracy, which brand of oil was being used, just by the colour and quantity of the exhaust smoke. Now you call call as much BS on that as you like, but it was a fact...

Chris......

If fact, have a look at some of the boating magazines around. They are always running whatever comparison tests. One that runs regularly is the different oils, and yes 50:1, and one of the comments is always the different amounts of smoke each different oil produces.

 

[ippielb]

verified timing. Made and adjustment to get 4-6 degrees as mentioned right before the carbs open up. But I feel like I’m chasing my tail. I cannot get my boat to idle in gear it can idle nicely in neutral, but as soon as I put it into gear it putters out. I have it in a bucket with water. And within minutes the water has a dark murky film on the surface. Looks like used motor oil almost.

still the second carb(middle) when the idle screw goes inward the rpm increases drastically.

 

[ippielb]

Here’s a picture of the water in the tub, you can see the dirty film around the edge of the tub. That’s after I tried to scoop out the dirty surface.

there wasn’t nothing I could do to make the boat run right. So at my wits end I got the boat to idle, and I just let it idle and run the tank out of fuel since there wasn’t much left.

put some fresh 91 in with 50:1 ratio. Started it up, seemed to run better. So I went back and used this video https://youtu.be/eSk01fvCbec to get my boat set up. And sure enough, with the fresh gas, those instructions and slight slight adjustment from 1 and 3/4 turns out. It seems to run, and I can put it in gear and it will stay running.

 

[jimmbo]

What Rpm is it idling at Nicely in Neutral?

 

[ippielb]

I don’t have a tach, and my laser tach tool I accidentally left the batteries in it over winter and broke the tool. So I’ll have to go get another one. It’s a little higher then I would like, it use to idle lower. I took a video, I’ll upload it on YouTube and show the link.

 

[ippielb]

https://youtu.be/2XPGYM65Cs0

 

[jimmbo]

I’m impressed with the water pump, the water wasn’t high enough to ensure it was primed
1976 or 77
it sounds a little low on the rpms. 600 - 650 in gear, is usually what those engine are speced at

 

[ippielb]

I’m impressed with the water pump, the water wasn’t high enough to ensure it was primed
1976 or 77
it sounds a little low on the rpms. 600 - 650 in gear, is usually what those engine are speced at

When I get a tach I’ll set the rpm for that range when warm.

if I had the rpm any higher then this when I would put it into gear it would knock repeatedly and it just felt harsh on engagement.

 

[jimmbo]

Are you easing it into gear? If so, that's wrong. That motor is either Out of Gear or In Gear, shifts have to quick and smart.

When I said in gear, I meant on the boat, with the boat in the water, That way the Motor is in its Operating Environment, which is not always accurate in a test tank and impossible to create running on the garden hose. Same applies to carb Idle Mixture Adjustments

 

[ippielb]

Are you easing it into gear? If so, that's wrong. That motor is either Out of Gear or In Gear, shifts have to quick and smart.

When I said in gear, I meant on the boat, with the boat in the water, That way the Motor is in its Operating Environment, which is not always accurate in a test tank and impossible to create running on the garden hose. Same applies to carb Idle Mixture Adjustments

forgot to mention, I replaced the water pump when I bought the boat, greased it’s up nice when I put it together, and have made sure to never run the boat dry, so hopefully my efforts pay off and it lasts for as long as I use the boat.

I was absolutely trying to ease it into gear, figured it was like a transmission in a vehicle not a hard engagement. I use the boat for fishing, and with a 19p prop at my lowest speed I’m still going too fast.

have not gotten it into the water to do a final carb adjustment either. Can’t do a hole shot pull from idle to see if it bogs in a tub.

I have another couple things I need to do before I take it out in the water, remove the gas tank and fix the front hook, the backing for the hook must’ve rotted out and the hook is now loose, and the battery connections are quite poor, I forgot to unhook the battery in the fall when it went into storage because I had major back issues. And it’s not connecting well.

was thinking about getting rid of the primer bulb, and putting an inline fuel pump with a momentary switch so I could just hit the button to prime the system since I try to run the carbs low when I put it on the trailer so the fuel doesn’t drip down and make a mess like it always does when the engine is lifted.

also noticed one of the power trim cylinders has a slight leak. I’ll have to go get an oring to resell the end cap.

Have to change the oil in the gearbox, and then the trailer needs some new rollers.

hard to work on the boat for too long having back surgery over the winter. Not fun to lean to the side. But little by little getting it done.

 

[ippielb]

Here’s the boat.