Just purchased boat with mercury blue band 115 hp motor

[michael4124]

I purchased a 1983 Procraft 1650 V with a Mercury Blue Band 115Hp engine, serial number is 6200563. The boat had been sitting outside for at least a year and a half. When purchased engine would only turn over. After replacing head gasket, carburator gaskets and new floats. the engine will run but has a bad idle. I checked compression last night and all 6 cylinders were at 120. The engine will run roughly with a hose hooked up to it, forward and reverse both work. When i took the boat to the lake (wish i hadnt) the engine fired right up but wen i put it to gear it boggled down and quit. I have noticed from the bottom carburator that it is dripping gas when under pressure. I know very little about outboard motors and was wondering if anyone had any advice. I have read thru multiple posts about my issues and the majority check compression and spark. Has good compression i would assume with it being 120 and good spark. I am having trouble finding a service manual as most i am finding are for four cylinders and this one in particular is a inline 6. Any help would be nice?

 

[79Merc80]

Re: Just purchased boat with mercury blue band 115 hp motor

Hello and welcome to iboats.

First off, I'm curious how you changed a head gasket on an engine that doesn't have one. You might have changed the water jacket gasket, but no head gaskets on the inline 6's.

Secondly, change the water pump inpeller FIRST!!!

Thirdly, search the boatd for the "Link and Sync" and do that before trying to run it.

 

[michael4124]

Re: Just purchased boat with mercury blue band 115 hp motor

Can you tell i know alot about boats, i have looked at the lower unit and for the life of me cannot figure out how to get the lower unit off. I will search for link and sync. thanks

 

[Bamaman1]

Re: Just purchased boat with mercury blue band 115 hp motor

Congratulations on getting your later model Stack Six Merc. You cannot kill those engines. I still see the old 85 hp Mercs painted white from the early 60's on the lake.

You said you put new gaskets and floats in the carbs, but did you take carb cleaner and clean out every orifice? The drip, drip, drip is usually a stuck needle valve--due to dirty carbs. That'll make'em run rough every time.

As far as the lower unit, I don't remember exactly the setup on this engine. Look for a plug on top of the trim tab, and possibly a bolt or allen head nut underneath the plug. The trim tab will drop out, and there is probably a stainless steel nut underneath the tab. Possibly under the cavitation plate you'll find some stainless steel nuts to remove. Once you figure it out, it's a 5 minute job to drop the bottom end. Oh, yea--drop the plug and the air vent screw to get the fluids out of the lower unit first.

I have found that replacing the lower unit with the stick in neutral and the lower unit in neutral works best when you have someone kick it in forward--as you're pushing up on the lower unit. My lower unit slipped right in last time I changed the impeller.

Good luck. These are just minor aggravations that you'll figure out. If need be, check your local library reference section for a engine manual. These issues are also often addressed on UTube.

 

[michael4124]

Re: Just purchased boat with mercury blue band 115 hp motor

I took all three carbs off today and clean the heck out of them. Put back on and now the middle is dripping not the bottom, progress i guess, engine ran a little smoother. Will do it again tomorrow.
I ran out of daylight and will try the lower unit tomorrow as well. will keep you posted.

 

[79Merc80]

Re: Just purchased boat with mercury blue band 115 hp motor

The lower unit has one nut at the front (Above the lower unit) One on each side a little further back, one on each side under the cavitation plate and above the prop, and one under the trim tab. The trim tab is either an allen or a socket bolt through the hole above the trim tab.

Craig

 

[michael4124]

Re: Just purchased boat with mercury blue band 115 hp motor

Success I removed the lower unit now i just sit and wait for water pump gasket set and impeller to arrive. Anything i should be doing while waiting for the parts. Can i work on the carbs and such with out a lower unit attached, probably not since no water will be circulating thru engine to keep it cool. I did notice when i removed the lower unit that abvoe the propeller was an open hole it looked like something should have been there. it is about 3 inches in diameter i would say and it is empty. From researching that i guess that is where the captivation plate goes (whatever that is) am i correct on that.

 

[Bamaman1]

Re: Just purchased boat with mercury blue band 115 hp motor

The 3" hole should be where the sacraficial anode/trim tab goes. It adjusts your steering so the pressure is equal right and left. The cavitation plate is on top of your prop--with sharp edges. It's part of the lower unit.

You can rebuild your carbs without the lower unit mounted. Just don't run the engine until it's re-installed.

 

[michael4124]

Re: Just purchased boat with mercury blue band 115 hp motor

Just curious where you all buy your marine outboard parts? I ordered the water pump gasket kit from NAPA online but it seems to be taking forever for them to ship it. Just was curious since i do not have any local marine shops that i know off.

 

[merc850]

Re: Just purchased boat with mercury blue band 115 hp motor

I buy mine from a Mercury dealer - a lot of '70s parts are still available; and if you want to keep it going for a long time buy any critical parts you can find on ebay - carbs ignition etc. and the missing trim tab that fits in the large hole.

 

[michael4124]

Re: Just purchased boat with mercury blue band 115 hp motor

Do i need a trim tab with the fin on it or one that is flat?

 

[WinnipegBoatMan]

Re: Just purchased boat with mercury blue band 115 hp motor

Im just in the middle of doing a link and sync to my 88 Mariner 115HP inline 6, I finished last year fully rebuilding mine, from top to bottom. These powerheads are build strong, and are super easy to work on. For your fuel leakage, when you opened up your carbs, and put the new floats in, did you put in new needles and seats? If you did, you have to adjust the 2 float arms that are attaced to top of the carb float housing. If the adjustment is out, your going to have a chance that the floats won't press against the arms, and then seat the needle to stop the fuel. When I rebuilt my carbs, I put in a full kit, gaskets needles, ect.. and I used the wrong measurements, and I was always leaking fuel out of the bottom 2 carbs, because all the fuel is coming from the #1 carb on the top. I readjusted it, and no more fuel leaking.
Once you get the leaking stopped, and your LU back on, time to Link your carbs up. There is a really good post on here, that gives you step by step instructions on how to link them. It is basically making sure that all 3 carbs are exactly postioned the same, and have the same movement. The next step is the sync the carbs, and you get to do that on the water with a helper.. and its just adjusting your idle mixture, so she can purrr
Quick and easy!! as long as your do your PM work on these inline 6's, water pump, fuel filter, water seperator, and use good quality oil and she will last for a long time

 

[carholme]

Re: Just purchased boat with mercury blue band 115 hp motor

Michael;

Your s/n comes up as:

115 115 6-cyl 6006834 6262960 1982 USA

From here:

http://www.marinshopen.se/Motorer/O...cury2taktR66cyl80150hp/tabid/489/Default.aspx

It is a model:

1115622 MERCURY 1982 115

Parts listing:

http://www.crowleymarine.com/mercury-outboard/683.cfm

Service Manual P/N: 90-86134--4

http://kingston.kijiji.ca/c-cars-ve...utboard-OEM-Service-Manual-W0QQAdIdZ285464523

Gerry

 

[michael4124]

Re: Just purchased boat with mercury blue band 115 hp motor

Thanks for the Great Info Gerry and winnepegboatman. I sent the service manual guy a message trying to buy it hopefully he still has it.
I recieved my water pump gasket set today FINALLY!!!! anyways have a fun time getting new impeller and housing together. actually came on here to search for what people use as lubrication for doing this. I read dishwasher soap or KY was good since it will wash away once in the water. Is that okay?

 

[WinnipegBoatMan]

Re: Just purchased boat with mercury blue band 115 hp motor

When installing my impeller kit, I actually did mine dry. The trick is to rotate the drive shaft in the Correct direction when inserting it into the housing. I'm sure putting some soap on it will help with installing it, and won't affect the impeller, it should wash away almost instantly. The only problem i see is that the soapy water will then travel into the powerhead for a few minutes. Also when the impeller is out, visually check the lower oil seal, I had a bad oil seal under the impeller when I did mine, and its one of those seals that doesn't come with the kit. It prevents water from getting into the LU gear box, if it looks perfect , go right into installing the impeller and gaskets.
If you don't know the direction the drive shaft needs to turn, i'll let you know tonight when I get my manual out

 

[michael4124]

Re: Just purchased boat with mercury blue band 115 hp motor

I received my anode/trim tab plate yesterday. I went to put it on and noticed the propeller was hitting the tab. Must be an aftermarket prop. I emailed the supplier and he told me i could sand it down but my question is how far do i sand it? waht is the distance supposed to be between fin of trim palte and prop?

 

[bktheking]

Re: Just purchased boat with mercury blue band 115 hp motor

Probably a high rake prop, when I went to a Stainless on mine I had to switch tabs. On mine, the PO cut the fin off so just the plate it there now. Don't let go of the wheel when at speed is all I have to say!

 

[Chris1956]

Re: Just purchased boat with mercury blue band 115 hp motor

There are three types of zinc anode for behind the prop. One has the full fin, one has a smaller fin which will work with most high-raked props and the flat style. I recommend the one with the smaller fin. It works with my Rapture Prop, which has some extra rake.

 

[bktheking]

Re: Just purchased boat with mercury blue band 115 hp motor

I'll have to see if I can get one as well, thanks Chris.

 

[michael4124]

Re: Just purchased boat with mercury blue band 115 hp motor

I have a band saw and can cut the trim tab fin down i just need to know what the gap between the fin and propeller should be