Blueband identification and trouble

[wrxcobra]

Hi to all great forum
I have 2 problems
First I need help to id the year of my dads blueband its missing the id plate (asked my dad about it and he said yea that fell of years ago. I didn’t think it was important)
Ok it’s an 85 HP 850 blueband with thunderbolt ignition, 4 cylinder, didn’t have tilt or trim until we put it on. Its been a great outboard owned it since 1980 its only needed a power head about 15 years ago a prop that we destroyed on the rocks and the do service and impeller.
It had to put up with us as kids and all our friends’ water skiing all summer every summer. And know its taking my dad, me and my son fishing.
I’m going to have a look at the carbies this weekend am hoping that they have some id numbers that will help to narrow it down a bit.
Is there anything else that will help to id the year of the motor, are the stickers on the cowling the same or do they change from year to year?
Can anyone help or has anyone got photos that will help id the engine?
Second problem it doesn’t run right when we are heading home (I guess it like fishing also...lol)
Its fine starting and on the way out, but once its been sitting fishing, some times over 6 hr it has a problem its fine at slow speed but as I increase the power it chokes and jerks, its like it inst getting air or fuel. If I give it max power it jerks a couple of time and takes off like a rocket, it seams to have the problem between 10% and 90% throttle range.
I have changed the fuel line and tank they needed replacing anyway, and am going to change the spark plugs (although they aren’t that old) and also put a carby kit in it as soon as I can id the year of the engine. The other thing I was going to look at was the wiring as a few years back one of the wires was severally corroded.
Has anyone had a problem like this or can anyone suggest what to look at?
thank you for your time, hope you can help.
Daniel

 

[Plainsman]

Re: Blueband identification and trouble

The serail # may be stamped on the engine block. Mine is and it's on the starboard side.

I'd check compression and spark. The carbs might need a rebuild as well.

 

[Chris1956]

Re: Blueband identification and trouble

Daniel, If it has a distributor, it is '73-74 or earlier.

 

[wrxcobra]

Re: Blueband identification and trouble

Thanks for your help so far, I will check the block for the serail number this weekend, and im almost sure it doesnt have a distributor so I have narrowed it down to 1975,1976 or 1977.
any more information would be great.
thanks again
Daniel

 

[wrxcobra]

Re: Blueband identification and trouble

Ok I have found on http://www.oldmercs.com/197476Merc850.htm
That a 1975 has a distributor also so if someone can confirm this, its either a 1976 or 1977 and from the same parts list they look like they have different starter motors again if someone can confirm this it would be great, or if anyone knows any other differences the help would be great.
Daniel

 

[wrxcobra]

Re: Blueband identification and trouble

ok I have found the The serail may stamped on the starboard side of the engine block. it reads 73321 and the carby model number is WM5. I got a carby kit for it today and put it in Sat I am also replacing (not sure what its called) the inner side plate (where the water goes thruogh the two plates) on the port side of the block, as the inner plate was starting to show signs of pitting and was getting thin in a few spots.
would still like to find out if its a 1976 or 1977 engine is there any difference?
should note its an Australian engine not sure were it was built?
has any one got any ideas on what to check next if this dosnt fix the problem?
thank you for your help so far its been great.
Daniel

 

[Chris1956]

Re: Blueband identification and trouble

Dan, The water jacket covers should be identical across those years, as are most of the non ignition parts. You should be able to find a part number on the block or transfer cover that you could match to a serial number range on www.dougrussel.com

 

[wrxcobra]

Re: Blueband identification and trouble

had a look on the side of block the number read 73321 with the number on the carby wm5. cant find eny refrence to the number on the block anywhere.
Still waiting to hear if anyone has any ideas on getting the problrm sorted.
Daniel...thanks

 

[Chris1956]

Re: Blueband identification and trouble

Dan, Look for a part number on the block or transfer cover. Go to www.dougrussell.com and browse the parts. If you methodically look at all the serial number ranges for the 850, you will find one or more serial ranges that contain the part number for your block and/or transfer cover. You will then know the serial range, which is important for getting the correct parts. You can check www.maxrules.com for info on year, using the serial range.

 

[TriadSteeler]

Re: Blueband identification and trouble

This might all be academic because the OP stated "Its been a great outboard owned it since 1980 its only needed a power head about 15..."

If the powerhead was replaced, then there probably wouldn't be a serial number on it. However, if it was a rebuild then you may have a chance.

On my '74, the serial number is stamped on a little flat area between the cylinder humps on the water jacket on the starboard side of the block about an inch or two in front of the rear cowl support and is 7 digits long (Aussie SN may be different). Those numbers are really small and if there is any grease in that area the number could be hidden.

Post a pic if you can of the stbd side of the motor and maybe we can help id it.

 

[wrxcobra]

Re: Blueband identification and trouble

I will try and get some photos on soon, although from what I can tell the 1976 and 1977 are the same, having a close look at the engine I noticed that the choke wire had no inoculation on it, and it was sitting on metal, as I followed the wire down the loom it was the same on the other side, as well as three other wires as I rubbed then with my fingers the insulation just crumbled away so I will have to replace these wires, and the thick red wire was squashed and seamed to have a break inside the insulation. All the other wires look ok although I will check to make sure the are ok when I change the others.
I am currently having a problem with the carbie and have posted in a different post if anyone can help it would be great.
Thanks for all your help so far.
Daniel
1977 850 merc carbie (wm5) question

http://forums.iboats.com/showthread.php?t=197456

 

[TriadSteeler]

Re: Blueband identification and trouble

If at all possible try and soak the carbs in the cleaner. This worked wonders for me. Those plastic butter containers with the lids work great. I got some liquid cleaner and soaked them for a few days while spraying out the passages during that time. This helped get all of the varnish out of the bowls.

If you are changing the needle and seat, remember that those things may tend to stick a little initially. This may cause a fuel starvation issue as the needle may not drop with the float. give it a little time to get some oil around the needle and it should begin to work properly.

About that wiring. I noticed the same thing on mine. Bad choke wire. The closer I looked, ALL of my Internal harness wiring was shot. The insulation was cracking and the wire was green and dusty. My advice is to replace it all. Odds are that if some of those wires are bad, they are all bad. Don't risk frying a switch box or a rectifier because of a few inches of wire.

If you are squeamish about replacing the entire harness because they are $$$, I built my own from a PVC Elbow, some marine wire, and some Epoxy.

http://forums.iboats.com/showthread.php?p=1235891#post1235891