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Keep The Oil Injection or Remove It???

G

gflattmann

Member
Right at the end of the summer, around august or so, I realized my merc XR6 was leaking some fluid from what appeared to be the lower unit. I called the merc techinal support people and the guy had told me it could possibly be the oil injection going bad...I think he said maybe the oil injection pump was going bad and it was allowing access oil into the cylinders, so Im guessing maybe that would cause the gas and oil rich mixture to sit in the cylinders until I go crank the engine up in my driveway and notice some really thick thick black oil in the water running down the driveway.

Does this sound like the oil pump or lower unit? the few people Ive asked seem to think it was not oil leaking from the lower unit.

Anyhow, the engine is a 1994 merc XR6 that runs really good...and I want it to stay like that. I was thinking about removing the entire oil injection system if that was the reason for the really thick black oil substance Ive continued to notice.

So, does this sound like it is the anything to do with the oil injection? Or, is it the lower unit leaking fluid?

If there is nothing wrong with the oil injection, I was thinking of removing it anyway..... Comment????
 
Comment???

Injection is nice but can really go bad if it stops working. Mixing is more work but the piece of mind is worth it. my.02

If I had an older motor i would mix it. Actually I'd start mixing as soon as the warrenty is up!
 
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Dump it. Block it off. Premix is a little more work but not as much as paddling home for a major rebuild.
 
I would say if you have noticed black oil, it is likely coming from the injection system. The lower unit oil it typically blueish in color, and when you have a leak, it turns a milky white color.

I have done a lot of reading on the oil injection, come the spring time, I will be running premix.

Spencer
 
Have you checked the oil level in the lower unit to rule it out as a source of the leak? If the oil injection pump is allowing a large amount of oil to the rest of the system, then you should notice a higher consumption rate from the oil resevoir. If the oil injection pump were out of adjustment, you might see a rich with oil mixture at lower rpm, but maybe not as noticeable at higher rpm.
 
gflattmann said:
Right at the end of the summer, around august or so, I realized my merc XR6 was leaking some fluid from what appeared to be the lower unit. I called the merc techinal support people and the guy had told me it could possibly be the oil injection going bad...I think he said maybe the oil injection pump was going bad and it was allowing access oil into the cylinders, so Im guessing maybe that would cause the gas and oil rich mixture to sit in the cylinders until I go crank the engine up in my driveway and notice some really thick thick black oil in the water running down the driveway.

Does this sound like the oil pump or lower unit? the few people Ive asked seem to think it was not oil leaking from the lower unit.

Anyhow, the engine is a 1994 merc XR6 that runs really good...and I want it to stay like that. I was thinking about removing the entire oil injection system if that was the reason for the really thick black oil substance Ive continued to notice.

So, does this sound like it is the anything to do with the oil injection? Or, is it the lower unit leaking fluid?

If there is nothing wrong with the oil injection, I was thinking of removing it anyway..... Comment????
Click to expand...

I'm not buying it. If there is a seal leak in your lower end then exhaust can get in the gearcase and turn the oil black. It then leaks out the same way. You need to pull the plug and see what color the oil is. Also if the injection was pumping too much oil (unlikely) the motor would smoke like the dickens. You need to have someone who knows what they are doing actually look at it.

Personally I would not remove the oil injection unless there was clearly something wrong with it. I have been running them on many motors for 25 years and never had a failure.
 
last time I had a lot of black oily gunk 'near' my lower unit it turned out I had a stuck float in one of the carbs, allowing a super-rich mixture in two cylinders. Pull the cowl off, remove the carb cover, and fire that XR6 up on the hose and let it run. See any fuel pouring out the front of the carb? That's what I had.
 
JW said:
last time I had a lot of black oily gunk 'near' my lower unit it turned out I had a stuck float in one of the carbs, allowing a super-rich mixture in two cylinders. Pull the cowl off, remove the carb cover, and fire that XR6 up on the hose and let it run. See any fuel pouring out the front of the carb? That's what I had.
Click to expand...
had a customers boat was doing the same thing...float sticking,there was rubber from the fuel lines in the bowl
 
“Parts left out cost nothing and cause few service problems.” Charles Kettering. I'd keep it simple...
 
On my 1990 200s I removed it. The say if you turn them anywhere near 6000 rpms the gear will break.
 
I think the 6,000 rpm limit for the oil injection is a little low. My '95 225 Promax was a 6400 rpm motor with that same oil injection system, and it had the same factory warranty as any standard motor. I'd believe 6500 rpms was the safe limit for that plastic gear though :thumb:
I did worry about that system in all my Mercs, and some of my outboards were switched to pre-mix and some I left factory injected.
 
jw, i think your motor has a differnet gear than mine did. i had a plastic gear and i think the promax motors had a steel or aluminum gear because of the higher rpm limit. my 200 is only 56 to 5800 limit.
 
No, it was definitely plastic, as I pulled it and made sure it was OK the same time I had the reeds out for replacement. I didn't have the oil block-off kit at the time, otherwise I would have removed that system.
The race motors had no oil injection system from the factory, they were pre-mix from the get-go. Merc never made a 'better' oil injection system for different motors back then.

The Mercury specified RPM limits are actually the rpms Merc recommends for propping for best power, not necessarily the motor 'redline'. A standard motor has intake and exhaust port heights and exhaust tuners that are tuned for best power between 5400 and 5800 rpms whereas the Promax motors had larger and higher port openings and a shorter exhaust tuner, so they made best power near 6400 rpms. The engine internals were all the same otherwise, until you got to the race motors.
 
I wasn't sure on it, it just scared me with the plastic gear so would rather have a litter reassurance. Did the same thing on all my jet skis. I know my luck, if it wasnt for bad luck i wouldnt have any at all. Plus my motors are on the old side so probably more prone to breaking.
 
Used to be really easy to get the proper oil block-off kit from Rickracers online, but after that business folded years ago I wouldn't know where to find it.
 
I've never had any problems with the oil injection on any of my motors.

My wife drives the boat a lot in the summer when I'm on the road and I think the chances of her forgetting to put oil in the gas are better than the system failing.
 
JW said:
Used to be really easy to get the proper oil block-off kit from Rickracers online, but after that business folded years ago I wouldn't know where to find it.
Click to expand...

I ordered mine from ProMarine. Hopefully this link works.

http://www.promarineusaonline.com/retail/items.asp?c=1&page=2&sub=1-810&man=MER

I was having alarm modual problems on my XR2, and it was quite the expensive part to replace, even used, so I went ahead and ordered the delete kit. Honestly, its one of the best things I've done to my boat. I have a measuring funnel for the oil. So I run a tad bit rich, I use just under 3oz per gal of fuel, my fuel gauge is fairly accurate when the boat is on the trailer, so I figure out how many gallons I want to put in, then dump the oil in, and put that amt of gallons in. Perfect mix!

I also had decals made for the boat, one on the dash, and one next to the fill.

0716101529.jpg
 
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