Ignition Compatibility on 150hp Blackmax

[scout-j-m]

My dad bought a 1992 Procraft 185 F&S a couple years back that came with a 92 model 150HP Blackmax, SN# 0D145256. I posted some about it on here a while back but long story short it had catastrophic faiure on the port side cylinders I think. He since found and bought a 1989 model of the same motor, SN# 0C184366. Motor had 120 psi across all cylinders and overall a pretty clean motor for the age. It's on his boat now and has worked well for a while it's just barely been used since he put it on. Last time out it wouldn't go over 3k rpms and wouldn't even try to get on plane.

I haven't done too much to investigate it nor water tested it since other than check compression again (still good) and checked spark. Spark seemed weak to me using a real spark gap tester. I truly doubt it's an ignition issue but, in the event it is, are the ignition parts from the 92 model interchangeable? There are a few obvious differences including having 2 rectifiers vs 1, 4 yellow stator leads vs 2, and the switchboxes having different part numbers. Just wondering if anything ignition-wise is cross compatible in the event I find an ignition problem on the current good motor.

I thought the two motors were almost identical but looking them both over the other day im seeing a lot of differences I wasnt aware of. Aside from ignition components the carbs are a different design and fuel pump a little different and different location.

 

[QBhoy]

One of them might be an xr model 150 perhaps.
Anyway. Did the 150 on your friends boat ever run as it should, since putting it on ? If it hasn’t…have we thought about the prop being too much pitch, being the reason ?
Perhaps it’s a stator or regulator issue and not producing and sustaining voltage

 

[scout-j-m]

One of them might be an xr model 150 perhaps.
Anyway. Did the 150 on your friends boat ever run as it should, since putting it on ? If it hasn’t…have we thought about the prop being too much pitch, being the reason ?
Perhaps it’s a stator or regulator issue and not producing and sustaining voltage

It ran pretty well at first. It was a little slower than the the previous motor but they had different props on them as he never swapped them out. I can't remember exact speeds or revs but it probably ran in the low 40's at a little above 5k rpms....so while maybe not propped ideally, it was good enough to say the prop is "close enough" for now.

I feel like more often than not peoples issues are fuel related. And I'm not ruling it out, but in my experiences fuel issues cause sputtering, surging, bogging etc and this was still running smooth but with no power. Almost like a bank of cylinders wasn't working. I actually have it in a barrel right now and it's at least firing on all 6 as it idles because I can pull the plug boots off one by one and hear and feel the engine respond with a dip in revs. I do have a DVA adapter for my multimeter so I can hopefully eventually do a full resistance and voltage test.

 

[Chris1956]

Mercs have windings on the stator for low speed operation and separate windings for high speed operation. You might check your high speed winding.

The stator from the older motor should fit the newer motor, but you should check the part numbers on a site like crowleymarine.

 

[scout-j-m]

I just did static test of the stator and trigger on the 89 model that's giving me fits. I got 4100 and 3800 ohms on the stator low speed leads and then 120 ohms on both of the high speed ones. That's in spec for the 40 amp stator like the 92 model motor has (with 4 yellow rectifier leads). I can't find an exact spec for this older motors stator though with the 2 wire yellow leads. The chart on CDI electronics page says that one should be 5-7k ohms though.

The trigger leads were all 1200 ohms which is in spec. Didn't have time to check the coils nor could I find any info on checking the switchboxes themselves.

 

[Chris1956]

I don't have a spec for the older high speed windings (2 yellow wire stator), but would think they should be the same as the newer stators with the 4 yellow wires.

You might get on the CDIElectonics web site and see if they have a spec or a test for the switchboxes.

 

[Dukedog]

tha '89 is a 2.4 200 with a single water cooled reg/rec (very expensive) and matching stator.. tha '92 is a 2.0 motor with tha two reg/rec. and matching stator.. they will not interchange.. i think cdi makes a kit to mix n match tha different chargin' systems though.. never did any of that myself.. would be better off ta change to tha 4 yellow wire stator and two reg/rec system..
they only built tha water cooled junk for 3 years....

idle ok and run smooth up to 2800/3000 then jus quit pullin'?.. if so its probably stator.. switch box numbers don't really mater.. 'bout tha only thing thats changed with them since 1976 is tha part number.....

 

[scout-j-m]

tha '89 is a 2.4 200 with a single water cooled reg/rec (very expensive) and matching stator.. tha '92 is a 2.0 motor with tha two reg/rec. and matching stator.. they will not interchange.. i think cdi makes a kit to mix n match tha different chargin' systems though.. never did any of that myself.. would be better off ta change to tha 4 yellow wire stator and two reg/rec system..
they only built tha water cooled junk for 3 years....

idle ok and run smooth up to 2800/3000 then jus quit pullin'?.. if so its probably stator.. switch box numbers don't really mater.. 'bout tha only thing thats changed with them since 1976 is tha part number.....

Yeah it idles about perfect. Punch the throttle down all the way and it goes up smooth and quickly to about 3000 rpms and just hits a wall. Boat nose just lifts up and stern plows water. Engine, despite not going up in revs, sounds smooth and there is no miss, hesitation, surging, etc.

 

[scout-j-m]

tha '89 is a 2.4 200 with a single water cooled reg/rec (very expensive) and matching stator.. tha '92 is a 2.0 motor with tha two reg/rec. and matching stator.. they will not interchange.. i think cdi makes a kit to mix n match tha different chargin' systems though.. never did any of that myself.. would be better off ta change to tha 4 yellow wire stator and two reg/rec system..
they only built tha water cooled junk for 3 years....

idle ok and run smooth up to 2800/3000 then jus quit pullin'?.. if so its probably stator.. switch box numbers don't really mater.. 'bout tha only thing thats changed with them since 1976 is tha part number.....

Swapping the two reg/rec and stator seems like a good idea then. If I read the manual right, that newer stator is a 40amp one too.

Also, I was unaware they were different displacement blocks. What all models did they build off the 2.4l block? 150, 175, and 200? Is the difference the carbs and/or carb jetting? The V6 mercurys are still pretty confusing to me as someone who is pretty unfamiliar with them.

 

[scout-j-m]

Just adding a couple pics for clarity. BTW, the carb stamping reads WH-29 (hard to read).

 

[Dukedog]

tha # 0C184366 shows ta be a '89 2.4 200 on Mercnet site.. that one is not a 200 for sure.. looks like ya have a hodge podge (jus chargin' system maybe?) of a powerhead??? where did you get tha 0C184366 number?.. tha one in your pictures looks ta be no newer than '86.. could be a 2.0 150 or 2.4 175? don't remember what tha WH 29 came on.. tha 40 amp stuff didn't come out till '89 either..

merc blocks/horse power:
first generation blocks... non oiler/premix
'76 ta '79.. all 2.0's 150 ta 175 hp (think they did make a version of tha 2.0 with a 200 rating in '79 maybe?
'80 ta '82:
2.0 150 and 2.4 175, 200, 225 ('81 and 2).. most of the above had a 9 amp system on 'em

'83 second generation blocks. non oilers/premix
2.0, 150 and 2.4 175, 200
some 16 amp started showing up

'84 ta '90 second gen. oiler blocks/horsepower:
2.0 150 and 2.4 175, 200... 16 and 40 amp ('89/'90) stuff

there is some 2.0 135's all thru tha years also.. they were basically 150's with a coupla different things...
ALL 2.4's are chrome bore motors with tha exception of one.. tha XR4 had steel.. only steel 2.4 motor merc built..

this is what i can remember.. comin' from an OLD coffee and smoke stained head of mine.. sure i got some wrong and/or left some out (i'm sure i'll get corrected on here) but its all i got right now... maybe help a little.

 

[Chris1956]

The way I understand it, Merc made 2.0L blocks for the 135HP, 150HP, 200HP in the 80's. The 150HP and 200HP blocks became 2.4/2.5L blocks, and the 135HPV6 stayed with the 2.0L block. Just a bit of history.

The 135HPV6 is a very good motor, IMO. I had a '77 1500 IL6, which was a beast at midrange RPMs, but lacking at hole shot. However, skiers would get yanked out of their skis, if I did not cut the throttle when she reached 3000RPM.

At 3000RPM the speed would build really, really fast, a few seconds and the boat would hit 50MPH. 3000RPM was 30+ MPH, which is normally skiing speed.

The 135V6 is 100# heavier, but is as fast at top end as the 1500, and has the same power at midrange, and gives a lot more low end power.

This allows you to drive at more speeds. The 1500 had idle speed or planning speed of about 30MPH, but little in between. The V6 allows 20MPH at the lower limit, which helps limit rough water, and 60+MPH at the high end with the same prop.

My opinion is that the 2.0L blocks that made the 135/150/200HP motors were a bit low on torque, for the larger heavier boats. They are great for the light fast bass boats, and their high performance needs.

No help to your ign issue, I know.

 

[scout-j-m]

tha # 0C184366 shows ta be a '89 2.4 200 on Mercnet site.. that one is not a 200 for sure.. looks like ya have a hodge podge (jus chargin' system maybe?) of a powerhead??? where did you get tha 0C184366 number?.. tha one in your pictures looks ta be no newer than '86.. could be a 2.0 150 or 2.4 175? don't remember what tha WH 29 came on.. tha 40 amp stuff didn't come out till '89 either..

merc blocks/horse power:
first generation blocks... non oiler/premix
'76 ta '79.. all 2.0's 150 ta 175 hp (think they did make a version of tha 2.0 with a 200 rating in '79 maybe?
'80 ta '82:
2.0 150 and 2.4 175, 200, 225 ('81 and 2).. most of the above had a 9 amp system on 'em

'83 second generation blocks. non oilers/premix
2.0, 150 and 2.4 175, 200
some 16 amp started showing up

'84 ta '90 second gen. oiler blocks/horsepower:
2.0 150 and 2.4 175, 200... 16 and 40 amp ('89/'90) stuff

there is some 2.0 135's all thru tha years also.. they were basically 150's with a coupla different things...
ALL 2.4's are chrome bore motors with tha exception of one.. tha XR4 had steel.. only steel 2.4 motor merc built..

this is what i can remember.. comin' from an OLD coffee and smoke stained head of mine.. sure i got some wrong and/or left some out (i'm sure i'll get corrected on here) but its all i got right now... maybe help a little.

That serial number is off of the transom bracket so I guess that is a bad one to go by. I need to find the one on the powerhead itself. I looked on the top and there is one welch plug and another spot where it looks like one is missing. The present one has the numbers " 6568786" so it doesn't real like a serial number.I took a few pics of some numbers on the heads but I didn't see much other identification on the block.

 

[scout-j-m]

The way I understand it, Merc made 2.0L blocks for the 135HP, 150HP, 200HP in the 80's. The 150HP and 200HP blocks became 2.4/2.5L blocks, and the 135HPV6 stayed with the 2.0L block. Just a bit of history.

The 135HPV6 is a very good motor, IMO. I had a '77 1500 IL6, which was a beast at midrange RPMs, but lacking at hole shot. However, skiers would get yanked out of their skis, if I did not cut the throttle when she reached 3000RPM.

At 3000RPM the speed would build really, really fast, a few seconds and the boat would hit 50MPH. 3000RPM was 30+ MPH, which is normally skiing speed.

The 135V6 is 100# heavier, but is as fast at top end as the 1500, and has the same power at midrange, and gives a lot more low end power.

This allows you to drive at more speeds. The 1500 had idle speed or planning speed of about 30MPH, but little in between. The V6 allows 20MPH at the lower limit, which helps limit rough water, and 60+MPH at the high end with the same prop.

My opinion is that the 2.0L blocks that made the 135/150/200HP motors were a bit low on torque, for the larger heavier boats. They are great for the light fast bass boats, and their high performance needs.

No help to your ign issue, I know.

No, that's still very informative information. Maybe will come in handy once I get this one back going. Can compare performance numbers to what you stated here.

 

[Dukedog]

6568786 is good number.. you have ta put a "0" in front of tha 6568786.. "06568786"... they added tha 0 to all existing and new serial numbers in '90/'91 i believe..... its a '84 2.0 150.. its has electrics from tha '89... mystery solved...
chris is close with his rendition of mercs.. they built one 2.0 200 and that was '79.. tha only 2.4 150's built are tha XR4 and an EFI.. tha only 2.5 150 was tha XR6 and an 150 EFI.. all tha other 150's with carbs were 2.0's...... all 135's are 2.0 motors..

look here for a build date... m/d/yr.. its on tha block kinda behind tha bend in tha timing arm.. may not be real easy ta see but its there....

 

[Dukedog]

this one is a little better...

 

[QBhoy]

Sorry to jump onto your post. Just very closely related to this though. Maybe help, given the incredible knowledge in responses. Any idea what this engine is ? It has been re re decaled from what it was originally for sure. Or had a more recent cowl on it to original. It’s different to any other mercury 150 I’ve seen. Carbs are different and few other things. It has the decals and clamshell from the mid to late 80’s on it now. But that’s been put on her in the last decade. She had a different cowl decal style originally for sure. It’s got serious power in it. I’ve had a few 150 2.0 mercs and known dozens of others over the years…and none of them were anything close to as powerful as this. It has a different gear ratio and lower unit style to any of the 150’s I’ve had too. Visually different externally and also different looking when removing for the impeller.

 

[Faztbullet]

1984/85 2 liter..starter date code is 1985 and WH-29 are150 carbs

 

[QBhoy]

1984/85 2 liter..starter date code is 1985 and WH-29 are150 carbs

Faztbullet. I know I shouldn’t have jumped on this thread. But couldn’t resist…considering the guys like yourself getting involved..and the knowledge available as a result…so with a quick look at my old engine (the last pics posted there) anything odd you think of that engine ? Is it a normal 150 look to you ? The carbs look different under that cover, to the 1990ish 150 I had..and the 97/98’ 150 I had. Also different from the 88/89 200 I had, but more familiar to it than the 150’s anyway.
I’d say it’s a 2.0 anyway. Can’t get to the engine for a while to check any numbers. But it’s definitely strange looking in parts under the cowl and certainly the ratio is I think different to other I’m familiar with. That or it’s way more powerful. It’s ridiculous for the power it has. Without messing too much with props, I’ve only tried two props on it, with that boat it’s on now (engine actually belongs on my cvx16. It’s on that 17ft deep v Fletcher just for a wee while). 23” tempest had it at 60 gps on the first go. Then went to a laser 2 25”. It’s still pushing high rpms quite easily even with that. If allowed, I’m sure it would see further into the 60’s with prop messing. Before a carb clean recently, it’s ran crap on the cvx16, but still saw 66 gps with rpms that were a little high I’d think. How would I tell if it’s an xr model perhaps. The carbs ? Serial number obviously,

 

[Dukedog]

QBhoy... tha orginal poster's motor is a '84 2.0 150 motor with '89 electrics like said....

your motor looks ta be at least a 2.0 135/150 ta at most a 2.4 175.. if heads are correct with year then at least '87.. it will have a build date in tha same place as described above... carb number (WH ?) will be able ta tell horsepower probably....