Have about had it with this motor!

[PrinceValium]

I have a 1975 Mercury 150 hp outboard on my 1983 Malibu skier.

I have rebuilt the carbs and taken the motor to SEVERAL different mechanics in hopes of getting this motor to run right. All the electronics to include the distributor, coil, rectifier, switchbox, and plugs were replaced with stock parts since the ones that were on the were aftermarket and did not work properly. The stator was not replaced as the mechanic did not feel it was not working properly.

The last time the mechanic had it he stated that the bottom carb was flooding the bottom two cylinders with fuel and he said he took care of that problem and that the motor runs great and put out 145 hp the prop. (skeptical whether he actually did put it on a dyno)

When I took it to the delta yesterday it would flat out die when trying to give it any throttle. I was throughly disgusted once again and decided to try and set the air fuel mixtures there on the water. I put the boat in neutral and brought the idle up to about 1500 rpm and adjusted the screws all the way in till lightly seated then back out 2 turns.

After doing that the motor did not want to die but still had no real power and refused to go over 25 mph at WOT. The mechanic did set the timing and did a link and sync etc. The perplexing part was that the carb, that he stopped from flooding, did not have any effect when turning the idle screw all the way in! It did not want to make the motor die like the rest. Could he have adjusted the float level too low and that is why? The fuel bulb stays relatively hard even when running and I also tried squeezing it while running which had no effect. I have had no luck bringing this motor to mechanics them actually making it RUN so we could get some type of enjoyment out of it and I am about at my last straw with it.

Any suggestions would be greatly appreciated. I just have no clue what could be keeping this motor from running well.

Rob

 

[Dave1027]

Re: Have about had it with this motor!

Delta? What was the name of the shop? Was it Paradise Point?
It's funny your story sounds just like mine from years back. I also boat on the delta. Demand your money back and rebuild your own carbs. If they refuse sue 'em. Don't let these crooks get away with this stuff.

 

[Faztbullet]

Re: Have about had it with this motor!

Doubt he has a dyno that show hp but more likely pressures.. Sounds like bottom carb is not getting fuel and the old distributer are picky in their set-ups.

 

[merc850]

Re: Have about had it with this motor!

Well you said that you adjusted the low speed needles in neutral, it should be running in FWD at about 900 rpm after warming up - turn needle counterclockwise until running poorly, then turn in until running smoothly. This should be approx 1.25 turns out.
Also if your engine has carbs like the attachment, check the screens if you can. I found a "hairball" in my lower one!

 

[Gomer50]

Re: Have about had it with this motor!

If you can screw in the Idle mix screw and it has no affect on your motor then you do have a problem there.Start from there.I do know that if these carbs and timing are not in sync, that motor will not run worth a damn.I am sure the Merc. Wizards will chime in but I would guess those carbs need to come off (inspected maybe cleaned again) make sure your fuel pump is working properly,all fuel lines are in good shape.If all your igniton parts are new and working properly,good compression then its all about good fuel delivery and link and sync.This can be a real ball buster been there done that.I have a smaller motor (80hp)same kind of setup and it has given a run for my money since day one (a year ago).I havent given up yet.The guy's here will for sure guide you in the right direction.Dont give up (GOOD LUCK).

 

[PrinceValium]

Re: Have about had it with this motor!

Well after writing that...I went out determined to look at the bottom carburetor and see just how much fuel was in the bowl after pumping the bulb. I pumped the bulb until it was firm and then took off the top for the fuel bowl and found NO FUEL in the bowl!! The float was sitting in the bottom of the carb bowl! I bent the arms back up some and put it back in. It took forever and a day to get the motor started and then once it started it sounded good. It revved up well on the muffs after adjusting the idle screws again. I would shut it off and it would immediately fire right back up again.

The carb was still not leaking fuel but I did not have time to take the lid off and see how much fuel was in the barb after doing all that. At least after doing that adjusting the idle screw did have an effect on the motor.

I rebuilt these carbs myself and cleaned the carbs as good as I could spraying cleaner through all the fuel holes etc. The floats in the carbs are brand new as well. How much fuel should they hold? At least half of the bowl?

The shop is in San Mateo and it is called American Star Marine. I was originally calling him to replace this motor with something newer and something I could still get parts for. The guys seems pretty straight forward and seems to know what he is doing. He did call me back later this afternoon and offered to come get the boat and figure it out.

He had the harness, the distributor, the rectifier, the coil, the switch box off another motor and installed it on mine. It is hard to come by parts for this motor and I paid him to put them on and get this motor running like it should.

I did however start the motor and put a timing light on it at idle and it looked to be set to a little over 10 degrees? I thought it should be lower than that more like 8 degrees.

I did replace the fuel diaphragm already and apparently this fuel pump works off of suction.

I will adjust the idle screws like you said Merc and see how it goes.

Another issue is my rpm gauge is mot working so it is hard for me to see what my rpm is right now. I have no idea why it is not working...it is almost like the needle is stuck.

One question I do have is...is it possible for the distributor to be 180deg. out? I know that is possible in a car and wondered if it can be the same for an outboard.

Thanks Guys for the replies and sorry for the long write ups.

 

[j_martin]

Re: Have about had it with this motor!

Well after writing that...I went out determined to look at the bottom carburetor and see just how much fuel was in the bowl after pumping the bulb. I pumped the bulb until it was firm and then took off the top for the fuel bowl and found NO FUEL in the bowl!! The float was sitting in the bottom of the carb bowl! I bent the arms back up some and put it back in. It took forever and a day to get the motor started and then once it started it sounded good. It revved up well on the muffs after adjusting the idle screws again. I would shut it off and it would immediately fire right back up again.

The carb was still not leaking fuel but I did not have time to take the lid off and see how much fuel was in the barb after doing all that. At least after doing that adjusting the idle screw did have an effect on the motor.

I rebuilt these carbs myself and cleaned the carbs as good as I could spraying cleaner through all the fuel holes etc. The floats in the carbs are brand new as well. How much fuel should they hold? At least half of the bowl?

The shop is in San Mateo and it is called American Star Marine. I was originally calling him to replace this motor with something newer and something I could still get parts for. The guys seems pretty straight forward and seems to know what he is doing. He did call me back later this afternoon and offered to come get the boat and figure it out.

He had the harness, the distributor, the rectifier, the coil, the switch box off another motor and installed it on mine. It is hard to come by parts for this motor and I paid him to put them on and get this motor running like it should.

I did however start the motor and put a timing light on it at idle and it looked to be set to a little over 10 degrees? I thought it should be lower than that more like 8 degrees.

I did replace the fuel diaphragm already and apparently this fuel pump works off of suction.

I will adjust the idle screws like you said Merc and see how it goes.

Another issue is my rpm gauge is mot working so it is hard for me to see what my rpm is right now. I have no idea why it is not working...it is almost like the needle is stuck.

One question I do have is...is it possible for the distributor to be 180deg. out? I know that is possible in a car and wondered if it can be the same for an outboard.

Thanks Guys for the replies and sorry for the long write ups.

Idle timing (link n sync) is a starting place. Final adjustment sets the actual idle speed.

Do yourself a favor and get the book and rebuild the carbs right, before you burn down a piston. Then go through the other setup items yourself so you know they're right.

 

[PrinceValium]

Re: Have about had it with this motor!

Idle timing (link n sync) is a starting place. Final adjustment sets the actual idle speed.

Do yourself a favor and get the book and rebuild the carbs right, before you burn down a piston. Then go through the other setup items yourself so you know they're right.

Martin...there has already been a link n sync done on this motor. I do have a book and have the carbs rebuilt correctly as far as I know. What would make the motor not want to run more than 25 mph at WOT?

 

[PrinceValium]

Re: Have about had it with this motor!

One thing I have noticed since I bought the boat is that the wires that go to the stator are green in color and the coating is flaking off of the wires. could this be a big part of my problem with this motor?

 

[CharlieB]

Re: Have about had it with this motor!

The stator on your system is for battery charging only, you could remove the stator and it would not make a bit of difference in how the motor runs, at least until the battery voltage dropped low enough the ignition began having problems.

Pay attention to what these guys have already told you.

Carb cleanliness, float settings are CRITICAL.

Link-n-synch is absolutely critical.

Those staked 6's are great engines, once everything is dialed in following the manual to the LETTER, it will make a believer of you, when all else fails, READ THE BOOK!.

 

[PrinceValium]

Re: Have about had it with this motor!

Well after the adjustments I made to the lower carb float and adjusting the idle mixture screws I was amazed that it performed awesome today! It took a bit to start cold but when it fired up it sounded good and was very responsive! It wanted to jump right out of the water and on to plane right away. Thanks for all the suggestions and replies on the thread. I need a little bit of fine tuning still but it is night and day better than it was.

I think this is the best it has run since buying the boat several months ago.

Anyway thanks everyone for the replies...it is nice to have this forum to be able to get help when you need it....especially for greenhorns like me.

 

[PrinceValium]

Re: Have about had it with this motor!

Well you said that you adjusted the low speed needles in neutral, it should be running in FWD at about 900 rpm after warming up - turn needle counterclockwise until running poorly, then turn in until running smoothly. This should be approx 1.25 turns out.
Also if your engine has carbs like the attachment, check the screens if you can. I found a "hairball" in my lower one!

Merc...mine are sort of like that...and after reading your post I did check the screen in the fuel pump just to make sure and it was surprisingly pretty clean. It was nice to know that there was not a lot of junk in the tank.

One thing I am confused about is that I was told by the mechanic I met today to turn the mixture screws in until it runs smooth and then back out 1/8 to 1/4 turn from there. He said if you adjust it to run smooth you could possibly run too lean and burn up a piston or two.

Anyone agree with this or is this incorrect?

 

[CharlieB]

Re: Have about had it with this motor!

Idle mixture alone will not burn a piston, a restricted fuel supply or dirty main jet WILL be lean at WOT and melt a piston.

The 2 stroke carbs do not have an accelerator pump to provide additional fuel necessary for a fattened mixture required for powerful acceleration.

The idle mixture is set to 'best idle' while under load in the water and in gear, then further richened anywhere from 1/8 to 1/4 turn additional for that additional fuel for great acceleration.

Not all engines require the same amount of additional fuel, careful adjustment then testing by rapid throttle opening is recommended til it responds quick and clean with absolutely NO hesitation. Done.

 

[CVX20SPRINT]

Re: Have about had it with this motor!

I have a 1975 Mercury 150 hp outboard on my 1983 Malibu skier.

I have rebuilt the carbs and taken the motor to SEVERAL different mechanics in hopes of getting this motor to run right. All the electronics to include the distributor, coil, rectifier, switchbox, and plugs were replaced with stock parts since the ones that were on the were aftermarket and did not work properly. The stator was not replaced as the mechanic did not feel it was not working properly.

The last time the mechanic had it he stated that the bottom carb was flooding the bottom two cylinders with fuel and he said he took care of that problem and that the motor runs great and put out 145 hp the prop. (skeptical whether he actually did put it on a dyno)

When I took it to the delta yesterday it would flat out die when trying to give it any throttle. I was throughly disgusted once again and decided to try and set the air fuel mixtures there on the water. I put the boat in neutral and brought the idle up to about 1500 rpm and adjusted the screws all the way in till lightly seated then back out 2 turns.

After doing that the motor did not want to die but still had no real power and refused to go over 25 mph at WOT. The mechanic did set the timing and did a link and sync etc. The perplexing part was that the carb, that he stopped from flooding, did not have any effect when turning the idle screw all the way in! It did not want to make the motor die like the rest. Could he have adjusted the float level too low and that is why? The fuel bulb stays relatively hard even when running and I also tried squeezing it while running which had no effect. I have had no luck bringing this motor to mechanics them actually making it RUN so we could get some type of enjoyment out of it and I am about at my last straw with it.

Any suggestions would be greatly appreciated. I just have no clue what could be keeping this motor from running well.

Rob

These motors didn't put out 145 hp at the prop when they were brand new.After a statement like that I'd have trouble believing anything he told me.JMHO.

 

[PrinceValium]

Re: Have about had it with this motor!

These motors didn't put out 145 hp at the prop when they were brand new.After a statement like that I'd have trouble believing anything he told me.JMHO.

Trust me when I don't see it myself I am VERY skeptical of someone telling me that. I had my reservations after having to bring it back to him two times after they replaced the ignition parts. I even asked his helper if that actually occurred and he promptly told me he was not the one that worked on the motor...of course.

He did offer to come get the boat a third time and work on it and bring it back to me but I got it working on my own. (much to my satisfaction!) His shop is 1 1/2 hours away from me so I would have to pay two bridge tolls and three hours of driving to just drop the boat off to him....multiply that times 4 and you can see how upset I was! I am just so freaking happy I got it to run well! It has been bothering me every single night for months. I am one to not be able to let something beat me so I had to find a way to get it fixed...lol

All we want it another couple years out of this boat and we will be buying a newer ski boat.

 

[monk-monk]

Re: Have about had it with this motor!

Yeah...don't blame the motor (or give up on the motor)...the problem is the lack of knowledge of the mechanic that's been working on it !! Get a manual, read it and learn ! I just experienced a similar situation...thankfully, i have a good working knowledge of these motors, but i just purchased a nice old '75 boat from a guy, it has a '75 1150 on it...he told me it had a bad cylinder and he said he just had a mechanic go over it the previous summer and he was frustrated because he spent so much money and now it has a bad cylinder...WELL, once i got it home i started my inspection...it didn't take long for me to realize that the person that worked on the motor didn't have a clue about any of it...timing, link-n-sync...the carbs were only opening about a third of the way...it was rediculous...the previous "mechanic" is to blame for what happened to this motor! If your really interested in these motors, get a manual, read it and learn! EDUCATE, PREPARE AND APPLY...

 

[PrinceValium]

Re: Have about had it with this motor!

Yeah...don't blame the motor (or give up on the motor)...the problem is the lack of knowledge of the mechanic that's been working on it !! Get a manual, read it and learn ! I just experienced a similar situation...thankfully, i have a good working knowledge of these motors, but i just purchased a nice old '75 boat from a guy, it has a '75 1150 on it...he told me it had a bad cylinder and he said he just had a mechanic go over it the previous summer and he was frustrated because he spent so much money and now it has a bad cylinder...WELL, once i got it home i started my inspection...it didn't take long for me to realize that the person that worked on the motor didn't have a clue about any of it...timing, link-n-sync...the carbs were only opening about a third of the way...it was rediculous...the previous "mechanic" is to blame for what happened to this motor! If your really interested in these motors, get a manual, read it and learn! EDUCATE, PREPARE AND APPLY...

I do have a manual for the motor and a PDF parts list. If I could do all the work myself I would. I am still learning how to work on this outboard...and you sure hope you can trust someone that supposedly is certified to work on an outboard! Your parts on your motor are interchangeable with mine. I got my ignition parts from a 1150.

I am going to take the boat out to the lake and run a tank of gas though it and see how it does all day on the water before I can really breathe a sigh of relief. She did about 40 at WOT today with a 4 blade prop. I would think that is pretty good...and it sure felt like it was effortless getting there. (like it should be!) I am fearing however that I am under propped. I wanted a 4 blade for punch out of the hole for the kids to wakeboard. I will know for sure when I purchase a tach and see what she is really turning.

 

[monk-monk]

Re: Have about had it with this motor!

Your first paragragh tells me you won't be needing that other "mechanic" anymore...LOL..BTW, be careful with the prop changing deal...boat weight, cargo weight, RPM and torque value of the motor...linking and sycing to those values...just keep that in mind..

 

[PrinceValium]

Re: Have about had it with this motor!

Your first paragragh tells me you won't be needing that other "mechanic" anymore...LOL..BTW, be careful with the prop changing deal...boat weight, cargo weight, RPM and torque value of the motor...linking and sycing to those values...just keep that in mind..

If I change the prop I have to link and since again?

 

[milehighboater]

Re: Have about had it with this motor!

If I change the prop I have to link and since again?

No you shouldn't have to do it again as long as it was the right prop set-up to begin with. The only thing you might run into is if you put a higher pitch prop on the motor and it slows down your idle-in-gear too much. As long as you are at the correct RPM at WOT you are just fine.