Need help

Hi, I have a mercury 175hp blackmax that I have some questions on. Not sure if there is an issue or if this is how these old motors are.

Its takes several tries to start it. I prime the bulb, turn the key and let it go for a little bit. Stop, and then do it again. After a few tries it will start. The bulb seems to always be little firm. It seems to run fine, starts right up after its warmed up.

When I take a run, say 10 - 20 min run, and slow down to get to the dock, it sometimes dies, then it takes a bit to get it started again. I have to put in neutral a have the throttle at least half way to get it to start again. Im not sure where to start diagnosing this, or if this is a common characteristics with the older motors?

Any tips or help is greatly appreciated.

Let's just cover some recommendations- and you can look through them, and decide where you're needing attention:

-FUEL LINES: Read this post, and compare it against your boat/engine. DON'T overlook this one! http://www.bbcboards.net/zerot...first

-ALWAYS have engine at LEVEL TRIM when starting or idling (not trimmed up, or tucked in).

-ALWAYS pump primer bulb FIRM <u>before EVERY SINGLE</u> engine start.

-COLD STARTS ONLY: Throttle at IDLE POSITION. Key on- push "IN" for 10 seconds (one thousand one, one thousand two... you get the picture). THEN start.

-WARM STARTS (engine ran within last hour or two): IDLE position, NO CHOKE... just turn key. Apply throttle ONLY if engine seems to be flooded.

Thanks for the reply, I checked the hoses, the ones going to the bulb are the grey with blue label on them. I took the cowling off and they are black hoses in there. Should I change those ones also to the grey with blue label? I also noticed that the carbs have some gas on them, maybe a carb leak. Should I take it to a shop to have the carbs cleaned and new gaskets for that? Or is this something a novice can handle? If I take to a shop, what might I expect to pay?

Thanks again for your suggestions. I really appreciate it.

I would encourage you to replace the line between the BULB and the FUEL PUMP INSIDE THE COWLING.

As per the referenced post, also upgrade the PRIMER BULB, Rebuild the Pulse Fuel Pump (quite simple, actually), and REPLACE FUEL FILTER.

Then see where you're at.

One important note: IF the engine is not running right at that point- SHUT IT DOWN. On your 2-stroke engine (regardless of whether it's oil injected, or pre-mixed): Oil is delivered WITH the fuel.

So- if you have a FUEL DELIVERY PROBLEM.... you also have an OIL DELIVERY PROBLEM. http://www.bassboatcentral.com/smileys/eek.gif

Great! I'll give that a shot, Can you tell me what parts I need? The motors serial # is 0D007475


Thank you for all your help!

You'll need:

-816296Q03 Filter
-816311T Radius Head Tie-Wraps (10-12 of them)
-3/8" Fuel Line (EPA Approved, low permeation- YOU specify length from tank to bulb)
-Primer Bulb (Epa approved, low permeation)
-5/16" Fuel Line (Epa approved, low permeation- YOU specify length from bulb to engine)
-857005A1 Fuel Pump Kit

Sherm @ Sherm's Marine (or I) would be happy to assist you with parts.

Email or Phone are the BEST means of contacting the Parts Department(s). http://www.bassboatcentral.com/smileys/thumbsup2.gif

Thank you so much, I really apprciate you taking out time to help me out. I sent an email for prices. Thanks again. I'll post back once I get it all installed.

I do have a remote water seperator? Should I also replace the filter on that?

hello adams,all the advice you have gotten so far is excellent and right on the money,its in my belief however that the problem you are having is located in your "switch boxes" I have had the same exact problem with my 1985 tower of power inline 6 and beat the heck out of myself for weeks trying to figure the problem out to no avail, I was then told to check the switch boxes and sure enuff thats what the problem was, go here and order them,this place is very reasonable,should cost $150 or less at best.....http://www.outboardexchange.com/ I hope this helps you out...

mike

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by adamsj13 &raquo;</td></tr><tr><td class="quote">I do have a remote water seperator? Should I also replace the filter on that?</td></tr></table>

ABSOLUTELY. Mercury doesn't recommend "additional filters"- but they can be utilized (if replaced AT LEAST annually).

Be sure to report back when you've had a chance to go through the fuel side of the system. http://www.bassboatcentral.com/smileys/wink.gif

I ended up taking it in to have them look at it. They found a crack in the exhaust plate. This is the part they said
http://www.mercurypartsexpress...77298

A little water comes and he said that the cawling is probably filling up with exhaust and thats why it dies at idle coming in from a run. He said my fuel lines look good and the carbs seem to be in synch. To fix the exhaust plate he gave an estimate of about 850 and worst case would be 1750 if there is more damage under the plate. He advised it would be fine to run it this way, just eventually the crack will get bigger and will need to be replaced. Would this crack cause all the issues?

I did as you recommended on pressing the key in for 10 seconds, making sure the primer bulb is firm and the motor is level. It did start alot easier following that. The fuel line the plugs into the motor, can I use a metal hose clamp for that. It currently has a ziptie and if I press the bulb to much, some leaks out of there.

With the 175 Blackmax, its on a Ranger 363 17'10" boat. I have a 23p laser II prop on it and seems to take a while to get on plane, How long should it take to get on plane?

If the fuel bulb leaks when you pressurize it, air can leak in when it is under a suction from the fuel pump.

My 1993 372 has a 150hp 1991 Mariner engine that has low hours on a rebuild. With my Laser ii 23 Pitch it planes immediately with partial throttle. With my 25 pitch Laser ii on it planes out very quickly. I don't think it should take more than half throttle, well maybe a little more, for a 175hp engine with a 23 pitch prop to put your boat on plane.

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by adamsj13 &raquo;</td></tr><tr><td class="quote">He said my fuel lines look good and the carbs seem to be in synch. </td></tr></table>

Read through the following post, and compare it against your boat. Don't take someone's word (the odds of a boat of this age having approved lines are next to ZERO... and you've already determined you have a LEAK):

http://www.bbcboards.net/zerot...first

Cracked exhaust plate should be addressed ASAP. Engine's don't run well "breathing their own exhaust". http://www.bassboatcentral.com/smileys/eyes.gif

Not knocking anyone elses advice, but you seriously need to listen to Don. He's been an ace Merc. Tech for many years & knows his stuff & goes completely out of his way to help us out. He's absolutley as good as they come & if anyone was guessing about my engine problems I'd want it to be him although he doesn't do much guessing He'll get you through this if you work with him for sure. http://www.bassboatcentral.com/smileys/thumbsup2.gif

I really appreciate you taking time out to help me. I will replace the lines and have the exhaust plate replaced. Would you mind if I post some pictures of how the hoses are run? Im confused on how the water seperator will be because there is a coupling or somthing connecting 2 hoses together.

What should I expect as far as hrs to complete the exhaust plate? They have to remove the power head? Right? I'll make the appt today to have them replace it.

Powerhead does have to be removed... and time can vary depending on "fastner corrosion".

You're welcome to post pictures....

And... you have an IM. http://www.bassboatcentral.com/smileys/wink.gif

I just looked at the hoses from the tank to the water separator and they are black, then from the separator to the hull is a connection that goes though the hull and then they are grey with blue lettering.

How many feet do you think it will take to replace all?

I setup an appt to have the exhaust plate replaced. Thanks for your advise :)

You're going to have to MEASURE to determine fuel line length needed. Unfortunately, there's simply no accurate way for me to "guess". http://www.bassboatcentral.com/smileys/wink.gif

Thanks Don for all your advise.

I had them replace the exhaust plate and seems to be a world of differnece. It was a little pricey but is well worth it. I get up on plan a lot quicker now and think I need to get a 24p prop iinstead of the 23p laser II I have on there now. At WOT I'm getting higher RPMs close to 6k but I didnt let it go past 5700.

I still need to run the fuel lines from the tank to the motor. Thanks again for all your advise and help.