How to adjust idle 150hp

[maxturbo]

I have a 2001 merc. 150 hp saltwater Carb.Motor. Problem im having is when it starts cold or hot the idle is really low worse when its hot. I have to put it in gear when Im out fishing so it wont stall. Once it starts and I run it for say 5 min. moving to my next fishing spot. It will idle fine in neutral until i shut it down. Once I shut it down and fish for about 30 to one hour. And try to start it takes about 5 min. to get it to start. And there I go again putting it gear as soon as it barely starts.

Are there any Cert. Merc. Mechanics in NJ willing to do some side work for me? Want my whole motor looked at. I've been to several marinas where they say they work on mercs. But when you see these guys you wouldnt want them near your boat.

 

[maxturbo]

Re: How to adjust idle 150hp

any ideas?

 

[Alvarez]

Re: How to adjust idle 150hp

Basically is hard to start and when it does it stalls on low idle then you press the neutral to get some rpm's then it runs good on low idle until it shut's back down for 30 min or more.Are you priming the primer bulb?Also are you pressing in the key and using the choke.What i see is that the carbs are getting flooded with gas.Do you have the mercury model 150xl swb.I have one a 2003 and i know many people with the same motor and starting problems.First of they are good engines.I recommend new spark plugs a primer bulb and fuel filters on engine and water seperator.Tell me how you start it the steps you do.Before I can determine if you have the carbs with sludge from old gas but i doubt it because once it burns the gas it runs fine.Or another problem with the choke system .But do a spark plug change and filters and that there will cure most problems...

 

[hkeiner]

Re: How to adjust idle 150hp

You might try performing a few things yourself to possibly narrow down or eliminate some possible causes. If you report the results of these tests on this forum, you may also get some more helpful advice. Some tests include:

1) Performing a compression test on all cylinders.
2) Test the strength of the spark at idle using an in-line spark tester.
3) Squeezing the fuel bulb while cranking to see if it helps with starting.
4) Check the link and settings according to the shop manual.

Cleaning the carbs and adjusting the floats is also a good idea if you don't know that it has been done recently or correctly.

Also, when my 150HP Merc is warm, I usually start it with the throttle a little forward of neutral (but out of gear) to allow a bit more air into the carbs when cranking. Once it starts, I can return the throttle back to neutral to keep it running. If I try to start the motor in neutral when it is warm, it will easily flood.

Just my thoughts...

 

[maxturbo]

Re: How to adjust idle 150hp

Basically is hard to start and when it does it stalls on low idle then you press the neutral to get some rpm's then it runs good on low idle until it shut's back down for 30 min or more.Are you priming the primer bulb?Also are you pressing in the key and using the choke.What i see is that the carbs are getting flooded with gas.Do you have the mercury model 150xl swb.I have one a 2003 and i know many people with the same motor and starting problems.First of they are good engines.I recommend new spark plugs a primer bulb and fuel filters on engine and water seperator.Tell me how you start it the steps you do.Before I can determine if you have the carbs with sludge from old gas but i doubt it because once it burns the gas it runs fine.Or another problem with the choke system .But do a spark plug change and filters and that there will cure most problems...

Thanks for the response. But this is what I have replaced before season started. The fuel filter, water seperator, plugs, batteries, water pump impeller kit, lower gear oil. I run 93 octane fuel also. Before I start in the am I prime the bulb till it gets hard. Than I try to start. Takes a while to get started. I do press down for the choke in the am. But the idle stays in the low range when cold or warm. Worse when warm thats when i have to put it in gear as soon as the motor starts before itll stall. Than Im fine.
Do you press down on the choke once or do you hold it down while cranking? Till it starts.

 

[maxturbo]

Re: How to adjust idle 150hp

You might try performing a few things yourself to possibly narrow down or eliminate some possible causes. If you report the results of these tests on this forum, you may also get some more helpful advice. Some tests include:

1) Performing a compression test on all cylinders.
2) Test the strength of the spark at idle using an in-line spark tester.
3) Squeezing the fuel bulb while cranking to see if it helps with starting.
4) Check the link and settings according to the shop manual.

Cleaning the carbs and adjusting the floats is also a good idea if you don't know that it has been done recently or correctly.

Also, when my 150HP Merc is warm, I usually start it with the throttle a little forward of neutral (but out of gear) to allow a bit more air into the carbs when cranking. Once it starts, I can return the throttle back to neutral to keep it running. If I try to start the motor in neutral when it is warm, it will easily flood.

Thank you for your response as well.
One time while my boat was docked i was flushing motor after a day of fishing. When the idle was low and it looked like it was goin to stall. I squeezed the primer to giv it more gas and see if that was the issue. Boy was i wrong. It flooded, stalled out motor. I had to hold down throttle plates wide open to get it to start than feathered throttle linkages to clear out gas. Boy did it smoke.
As far as cleaning carbs all that Ive done was spray carb cleaner or that foam stuff when I winterize the motor. I know the floats never been adjusted. Is that something easy to do?
I think if i had a compression issue I would have the problem all the time right?
I do believe i need a starter too cause sum times all it does is make a hum noise from the starter n doesnt seem to hav enough power to engage the flywheel thats what it seems like. Even tho I see the gear move up.
But the starter doesnt have anything to do with the low idle .

 

[Alvarez]

Re: How to adjust idle 150hp

You prime until it feels a little hard not too much it will flood.Then you turn the key and start while pushing the choke until it starts.If it don;t work the first time wait 10 seconds and hit the key again but no more priming and no choke..

 

[maxturbo]

Re: How to adjust idle 150hp

You prime until it feels a little hard not too much it will flood.Then you turn the key and start while pushing the choke until it starts.If it don;t work the first time wait 10 seconds and hit the key again but no more priming and no choke..

Thanks I will give that a shot in the am when i first start it. But what about when its already warm? I dont prime it nor use the choke and i still have a hard time starting it. Just doesnt seem to want to start n idle.

 

[gss036]

Re: How to adjust idle 150hp

I had a 200 hp Merc it required a short prime push on the key and it would fire right up, you get the hang of it after a bit.
You are wasting your money on 93 octane gas, just don't need it.

 

[j_martin]

Re: How to adjust idle 150hp

I had a 200 hp Merc it required a short prime push on the key and it would fire right up, you get the hang of it after a bit.
You are wasting your money on 93 octane gas, just don't need it.

I beg to differ,
You don't need the octane, but it's worth real gold to get rid of the alcohol.

A friend of mine just had a nice day wrecked by phase separation in the fuel for his toon. Family was pretty disappointed that the thing wouldn't go.

I fought fuel problems for half a summer when I first got my XR4. Since I cleaned it all out and have run 92 octane, I have no problems. The gas I'm burning now I put in drums in February, with a little StaBil. I'm having no problems at all.

hope it helps
John

 

[maxturbo]

Re: How to adjust idle 150hp

I beg to differ,
You don't need the octane, but it's worth real gold to get rid of the alcohol.

A friend of mine just had a nice day wrecked by phase separation in the fuel for his toon. Family was pretty disappointed that the thing wouldn't go.

I fought fuel problems for half a summer when I first got my XR4. Since I cleaned it all out and have run 92 octane, I have no problems. The gas I'm burning now I put in drums in February, with a little StaBil. I'm having no problems at all.

hope it helps
John

Thats exactly why i use 93. Ive heard alot of nightmare stories down at the marina from people using 87.
the higher the oct the cleaner the burn.

 

[j_martin]

Re: How to adjust idle 150hp

Thats exactly why i use 93. Ive heard alot of nightmare stories down at the marina from people using 87.
the higher the oct the cleaner the burn.

Actually, the higher the octane is over what's needed, the dirtier the burn is likely to be.

That's not the point. With ethanol in the fuel, it will attract water. When it does, the alcohol and water will tend to combine and drop out. The crap that drops out has too much water to burn, and the fuel that's left will have a much lowered octane, possibly causing other problems. Thus a fuel/water seperator is only part of the solution. Avoiding alcohol like the plague is the other part.

 

[hkeiner]

Re: How to adjust idle 150hp

Getting back to the original problem... You said:

"When the idle was low and it looked like it was goin to stall. I squeezed the primer to giv it more gas and see if that was the issue. Boy was i wrong. It flooded, stalled out motor. I had to hold down throttle plates wide open to get it to start than feathered throttle linkages to clear out gas. Boy did it smoke"

The motor should not respond to squeezing the bulb like that, unless you squeezed it really hard. Gently squeezing the bulb normally should only help the moter run better and only if the fuel pump is weak. Otherwise, there should be no noticable effect. Since the motor did respond as you describe, I would suspect that a float inside one or more carbs is leaking fuel, due to either the float level being set too high or a float needle being worn. Of course, the difference between a too hard squeeze and a gentle squeeze is hard to describe.

As far as cleaning carbs all that Ive done was spray carb cleaner or that foam stuff when I winterize the motor. I know the floats never been adjusted.

Cleaning the carbs requires taking them apart and soaking the parts in a can of parts and carb cleaner (see below link). Spraying cleaner into the throats of the carbs while the carbs are on the motor will not clean them. It is not very hard to clean carbs on an outboard, but a shop manual would be helpful if you have never done it before. At a minimum, you need a parts diagram for the carbs so you know what parts go where during reassembly.

If I were in your situation, I would not frustrate myself any further trying to diagnose the problem without first cleaning and adjusting the carbs and then doing a link and sync.

http://forums.iboats.com/attachment.php?attachmentid=24224&d=1236725519

 

[maxturbo]

Re: How to adjust idle 150hp

Getting back to the original problem... You said:



The motor should not respond to squeezing the bulb like that, unless you squeezed it really hard. Gently squeezing the bulb normally should only help the moter run better and only if the fuel pump is weak. Otherwise, there should be no noticable effect. Since the motor did respond as you describe, I would suspect that a float inside one or more carbs is leaking fuel, due to either the float level being set too high or a float needle being worn. Of course, the difference between a too hard squeeze and a gentle squeeze is hard to describe.



Cleaning the carbs requires taking them apart and soaking the parts in a can of parts and carb cleaner (see below link). Spraying cleaner into the throats of the carbs while the carbs are on the motor will not clean them. It is not very hard to clean carbs on an outboard, but a shop manual would be helpful if you have never done it before. At a minimum, you need a parts diagram for the carbs so you know what parts go where during reassembly.

If I were in your situation, I would not frustrate myself any further trying to diagnose the problem without first cleaning and adjusting the carbs and then doing a link and sync.

http://forums.iboats.com/attachment.php?attachmentid=24224&d=1236725519

Thank you for your input. What is the Link and sync? That you describe.
When the boating season is over which is mid Oct. I'll remove the carbs and get that can of cleaner like you have. Thanks again.

 

[hkeiner]

Re: How to adjust idle 150hp

What is the Link and sync?

Link and sync are the steps followed to adjust the carb and ignition linkages (and related components) to specs. If the link and sync is not done correctly, the motor will most likely not run correctly. The shop manual for your motor will describe the linc and sync procedures in detail.

 

[maxturbo]

Re: How to adjust idle 150hp

Link and sync are the steps followed to adjust the carb and ignition linkages (and related components) to specs. If the link and sync is not done correctly, the motor will most likely not run correctly. The shop manual for your motor will describe the linc and sync procedures in detail.

Thank you. Is that something easly done with the manual? Or should i just let the pros do it. Sounds expensive.

 

[hkeiner]

Re: How to adjust idle 150hp

As an owner of a 150hp outboard, you should have a shop manual for it. Read the sections on maintenance and link and sync to get an idea of what is involved. Only you can decide if you are up to the task of doing the work yourself. If there are steps in the manual that you don't quite understand, you can ask about them on this forum. It is not practical or possible, however, to try to learn everything on this forum only. A shop manual is a must have in my opinion.

Generally speaking, it is much more expensive to own an outboard motor if you have the "pros" do all the work for you. For some, that is not a problem. For others, it is. I belong to the second group.

 

[maxturbo]

Re: How to adjust idle 150hp

As an owner of a 150hp outboard, you should have a shop manual for it. Read the sections on maintenance and link and sync to get an idea of what is involved. Only you can decide if you are up to the task of doing the work yourself. If there are steps in the manual that you don't quite understand, you can ask about them on this forum. It is not practical or possible, however, to try to learn everything on this forum only. A shop manual is a must have in my opinion.

Generally speaking, it is much more expensive to own an outboard motor if you have the "pros" do all the work for you. For some, that is not a problem. For others, it is. I belong to the second group.

I hear you. Getting a shop manual tomorrow. I too belong in the second group.
You guys have been a great help. Thanks again.

 

[hkeiner]

Re: How to adjust idle 150hp

The Mercury OEM shop manual is considered by most as much better than those published by 3rd parties, such as Seloc. I happen to have both a Seloc and a Mercury manual for my motor, as each has something extra to offer the other does not. As a newbie, I liked to read both manuals on a new subject to get the best possible understanding. If you get only one manual though, I strongly suggest it be the Mercury one. Just my thoughts...

 

[maxturbo]

Re: How to adjust idle 150hp

The Mercury OEM shop manual is considered by most as much better than those published by 3rd parties, such as Seloc. I happen to have both a Seloc and a Mercury manual for my motor, as each has something extra to offer the other does not. As a newbie, I liked to read both manuals on a new subject to get the best possible understanding. If you get only one manual though, I strongly suggest it be the Mercury one. Just my thoughts...

Picked up the Mercury one this morning. Wow theres alot of info and diagrams. This is my bible