Merc 125 1250

[zopperman]

Potential purchase...

Guy wants 400... comp is 100 across all 6 cyl, comes with controls... I will be doing a survey of sorts on it checking comp myself running it in a bucket ETC.

Sound like a good deal? He also said it's been sitting for a while so I'm anticipating a carb cleaning and stuff.. DO these have a powerpack or a distributor?

 

[79Merc80]

Re: Merc 125 1250

They have a distributor and a switch box. Also should have the water pump impeller changed. I think 400 is a good price if it runs.

HTH, Craig

 

[zopperman]

Re: Merc 125 1250

Thanks Craig. I'm definitely going to negotiate a little, hes had it up for a while without a sale and seems to know very little about it. It's gotta be a pretty heavy motor with the i-6, isn't it? What year could it be from?

Anything else to look out for? I've never dropped the LU on a merc before, is it easy? Similar to a chrysler?

 

[79Merc80]

Re: Merc 125 1250

The 1250 was only made in 68 and 69.

I have never taken the lower unit off of a Chrysler, so I don't know. There is one nut in the front above the Anti-Cavitation plate, 2 (One on each side) above the plate, 2 under the plate above the prop, and one under the trim tab.

The engine weighs about 385#'s. Not very heavy, but defiantely awkward, not bad with 2-3 people.

Craig

 

[gwukena]

Re: Merc 125 1250

The 1250 was only made in 68 and 69.

I have never taken the lower unit off of a Chrysler, so I don't know. There is one nut in the front above the Anti-Cavitation plate, 2 (One on each side) above the plate, 2 under the plate above the prop, and one under the trim tab.

The engine weighs about 385#'s. Not very heavy, but defiantely awkward, not bad with 2-3 people.

Craig

I think he may have meant 285 lbs, correct?

 

[zopperman]

Re: Merc 125 1250

Great, sounds easy enough.. I've never worked on a merc before, but I'm expecting to do the general stuff like carb cleaning and replacing fuel lines and all that. The guy doesn't have a key for the controls. I'm going to jump the starter and test for spark.. if it cranks and I have spark I'll get it (since im assuming gummed up carbs) and if I can a good comp. test...

He also said it has power steering... will my teleflex steering cable be compatible with that?

 

[zopperman]

Re: Merc 125 1250

and I heard this was a prototype corssflow engine... is that true? the first year that they stopped making loopers...?

 

[turtles11756]

Re: Merc 125 1250

use a different gauge the readings should be closer to 125psi. be careful taking the carbs off you can really mess things up.open the lower unit gear lube drain screw and check what the lube looks like and try and shift it thru gears up top

 

[zopperman]

Re: Merc 125 1250

yeah im gonna check for milky oil.. and yeah i wanna run the motor at various speeds and in reverse... im gonna bring a gas tank and some jumper cables to rig the starter

 

[mr 88]

Re: Merc 125 1250

As noted your comp should be in the 120+ range and each cylinder within 5lbs of each other. There is no power steering on these motors and yes the telefex is compatible you may have to buy a steering link.Do NOT run the motor at high rpms without a load.You may put it through the gears at a low rpm and give it a little bump with the throttle and that's about it.If it starts and has good compression I would not worry about it running fast,it will on the water after a carb rebuild.

 

[Faztbullet]

Re: Merc 125 1250

My $.02, if you can get it for $200 its worth fooling with but I would not give much more than that. Save your $$ and you can find a later 74-79 115hp for about the price owner is asking for the 125. Parts are to high and scarce to fool with the 125. Check craigslist as there are some deals out there below is one.....
http://nashville.craigslist.org/boa/2571210862.html

 

[zopperman]

Re: Merc 125 1250

http://newjersey.craigslist.org/boa/2563233142.html


Something like that? I have a chrysler now and parts are a nightmare. I also found a v4 johnnyrude 115 that's appealing because it'll be lighter..

My top speed is 28 right now with a 70 HP... think I'd see 40 from a 115??

 

[79Merc80]

Re: Merc 125 1250

Speed depends on a lot of factors, including type, weight, and length of boat, but 40 for a 115 is not out of the question.

Yes, the 1250 was an engine all to it's self and unique. It was the first 99 CID engine and a lot of parts are not interchangable with other inline 6's.

Keep in mind that in 82/83 Mercury changed from Crankshaft rating to propshaft rating. So the pre 1983 115 becomes the post 1983 90 and the older 140 becomes the newer 115.

The second picture looks like an 80 - 83. It's hard to tell as the cowlings from all of the inline 6's are interchangable. In 1979 the distributer went away in favor of the ADI ignition.

Craig

 

[zopperman]

Re: Merc 125 1250

Thats very interesting, big loss of HP. I actually found a 79 115 Johnson for 800 running with a bimini top and seats in good cond. I haggled him to 400... I want to post up in the johnnyrude forum and get some info on the 79 115... anybody happen to know offhand if they rated at the prop?

 

[79Merc80]

Re: Merc 125 1250

Not a loss of HP. The industry changed where the HP was rated. Prior to 83 the HP was rated at the crankshaft, now it's rated at the propshaft.

 

[Faztbullet]

Re: Merc 125 1250

The 1979 115 Johnrude is about 98hp at prop where as the 115 Merc you posted is 115hp at prop......

 

[zopperman]

Re: Merc 125 1250

would the weight of the extra two cyl negate the extra HP??

 

[zopperman]

Re: Merc 125 1250

also, according to Craig above, merc changed their rating location in 82/83 so the 76 should be rated at the crankshaft...?

 

[79Merc80]

Re: Merc 125 1250

Correct, 76 is crankshaft rated. A 76 115 would be comprable to a 83 and later 90HP.

The inline 6 even with 2 extra cylinders is surprisingly light, so no really an issue.

 

[zopperman]

Re: Merc 125 1250

SO would I see much of a difference form my 70 HP chrysler (rated at prop I believe) That merc is 500 but the guy says it has brand new carbs too...