Merc 170 Problems. Please Help.

[fireplayer95]

I have a Mercruiser 170 in a Searay Seviile 5.6. I have been having some issues with a few things that some may know the solution to. First issue is when I turn the key to start then engine, the starter keeps tring to start. Good thing I have a kill switch on my battery. Second thing is it will not start with the throttle lever in idle. I have to push the throttle only button, give it tons of gas and then maybe it will start. Third, when out on the water it runs good in WOT, but when I bring it down to the neutral position the engine dies and will not restart. I have done done anything, so it is as it reads. Any help, tips, suggestions would be awsome.

 

[ErieRon]

Re: Merc 170 Problems. Please Help.

I have a Mercruiser 170 in a Searay Seviile 5.6. I have been having some issues with a few things that some may know the solution to. First issue is when I turn the key to start then engine, the starter keeps tring to start. Good thing I have a kill switch on my battery. Second thing is it will not start with the throttle lever in idle. I have to push the throttle only button, give it tons of gas and then maybe it will start. Third, when out on the water it runs good in WOT, but when I bring it down to the neutral position the engine dies and will not restart. I have done done anything, so it is as it reads. Any help, tips, suggestions would be awsome.

If you could post a year and serial number it would help...and what drive. Also, you can download the service manual here at iboats for free at this link; http://forums.iboats.com/showthread.php?t=288430 (probably #8)

It sounds like you have a problem with your ignition switch, starter solenoid, shift interrupter...or all of them. I would start by reading item 2 & 3 at the above link to troubleshoot your starting system and interrupter switch, then after you have a better grasp on things repost.

 

[Alpheus]

Re: Merc 170 Problems. Please Help.

the starter keeps tring to start.

Do you mean that the engine is spitting and sputtering and is amost starting in that manner or it just turns over with no signs of life?

. I have to push the throttle only button, give it tons of gas and then maybe it will start.

Again is it spitting and sputtering and almost starting but when you give WOT it starts and slowly revs up?

When out on the water it runs good in WOT, but when I bring it down to the neutral position the engine dies and will not restart.

When you bring the boat down from WOT does the boat take a few seconds to quit or is it just shut off immediately as if you turned off the key?

If you answered yes to the first part of either question it could be the idle circuit in your carb is plugged up, spark plugs are bad or your bottom end is running way to rich.

If you answered yes to the second part of either question, it sounds as if your shift/ignition interrupt switch is out of adjustment.

I hope this helps

 

[Bondo]

Re: Merc 170 Problems. Please Help.

Ayuh,... Welcome Aboard fireplayer95,... It sounds like you've got Several things going on...

1st off,... I'm guessing the starter solenoid is about to bite the dust,...
When the spring gets old,+ the contacts get carboned up,...
The Starter just don't wanta give up when you let go of the key...

The Rest of your Problems I believe are from a need of a complete Tune-up, with extra special attention given to the Carb...
The low-speed circuit, the choke,+ the idle circuit are in Bad shape...
Probably otta check,+ change the fuel filters too...

 

[Don S]

Re: Merc 170 Problems. Please Help.

The 170 is a model number for a 470 engine and was actually out for only 2 years, 85 and 86.

Up in the Adults only thread at the top of this forum is links to the manuals. You need to download #8 for your engine. It will have all the info you will be needing.
#6 is for your outdrive.

 

[fireplayer95]

Re: Merc 170 Problems. Please Help.

If you could post a year and serial number it would help...and what drive. Also, you can download the service manual here at iboats for free at this link; http://forums.iboats.com/showthread.php?t=288430 (probably #8)

It sounds like you have a problem with your ignition switch, starter solenoid, shift interrupter...or all of them. I would start by reading item 2 & 3 at the above link to troubleshoot your starting system and interrupter switch, then after you have a better grasp on things repost.

It is a 1986 and the Serial No. is B405956 for the engine. Drive Unit is 0A620882. Transom Assembly is a699837.

 

[45Auto]

Re: Merc 170 Problems. Please Help.

Third, when out on the water it runs good in WOT

Running WOT out of the water (no load on the engine) could be the cause of a lot of your problems .......

 

[Fishermark]

Re: Merc 170 Problems. Please Help.

Running WOT out of the water (no load on the engine) could be the cause of a lot of your problems .......

If I understand the original post correctly, (and I may not be correct), he is saying he runs good in WOT "on the water" - not "out of the water." But you do bring up a good point that he should not run it in WOT on muffs out of the water.

 

[fireplayer95]

Re: Merc 170 Problems. Please Help.

I have not been able to do some testing yet or parts replacements, but this is what I did do. I invested in Salt Away and ran it through the system for about 20 minutes. I was able to get it start right up after that. Maybe it just needed a good flushing. Now just when I thought things were looking better I noticed the cap to my cooling system had a large amount of steam escaping from with a little antifreeze seeping out. Is this a faulty thermostat. I still plan on replacing a few things and getting a good tune up for it. I also noticed that it idles at about 1000 rpm, seems a little high.

 

[Don S]

Re: Merc 170 Problems. Please Help.

Flushing the raw water system with Saltaway, has nothing to do with the starting system of an engine with a Closed cooling system.
Carbed engines also requier pumping of the throttle to get fuel to the engine from a carburator, unlike EFI in your car. If your carb leaks fuel out of the bowl after a few days, that will cause you to have to crank the engine a long time to fill the bowl up so it will start.
Flushing has nothing to do with your problem.

 

[Bondo]

Re: Merc 170 Problems. Please Help.

Maybe it just needed a good flushing.

Nope,... A snowball's chance in 'ell...

Is this a faulty thermostat.

How Hot was it,..??
Again, Doubtful...

I also noticed that it idles at about 1000 rpm, seems a little high.

You're Right,... 650/ 750rpms is where it Should be....
Which relates back to the Bad carb,+ Need of a Tune Up....