Lower Unit Identification

[Gotfish?]

2012 ProXS 250 Serial# 1B861456 on 2012 Ranger Z521

i got the boat used a few years back and unfortunately don’t run many hours annually but have stayed on top of the suggested Mtc from this site, thanks for an awesome resource.

Last time out at WOT it made a loud clunk noise (not a bang) and came off plane and shutdown. It let me start right back up but couldn’t go over idle to get back to ramp, motor shook pretty bad too on ride back but made it. I don’t think I hit anything while on plane and was running along fine until it wasn’t.

It will go in forward and reverse but it is clunking some in either gear, not in neutral so I’m assuming lower unit gear issue. I changed lower unit oil and no metal shavings on magnet or any water intrusion, oil wasn’t milky.

I think the lower unit might not be original, maybe aftermarket so I want to make sure if I don’t have right lower unit that I get the right one to go back in it’s place.

Thanks for any thoughts.

Jason

[lpugh]

Compression test and borescope the motor

[bass.man65]

Post a pic, also where was the drain screw located?

[Gotfish?]

I’ll grab a pic later, drain screw is underneath the prop

[JOE54]

Compression test and borescope the motor

^^^^^+1 plugs and look for any metal or gray material on end start with number 6 port bottom

[Gotfish?]

Will schedule it in for compression check and borescope as recommended.

I can check plugs prior also, if I get a chance to take them out I’ll post pics later this week.

[JOE54]

when you pull plugs if you see metal or gray deposits on end dont worry about schedule , report back with pics good luck

[Gotfish?]

Will do and thanks for the input, sounds like maybe a top end issue instead of lower unit from your guys recommendations.

[JOE54]

check it out

[EuropeanAM]

Good idea to post a couple pictures of that gearcase.

[Gotfish?]

Thanks for input on this guys, taken longer to get around to this since got sick but back at it now. See pics of spark plugs, I did replace center starboard side plug due to porcelain/ceramic top broken around electrode when I took it out. I thought I saved it for picture but can’t find it after not being in my garage for a week, I have a new set so put new one in its place. Do you see any other concerns with plugs, all were replaced around 20 hours ago, also I verified gap is between 0.040(no touch) and 0.044 (touch).

8A867AB6-9240-4DF2-892E-DB50D5077F62.jpeg15C83E72-19A2-4CA1-BD90-7EC7A0C8FB69.jpeg

[Gotfish?]

2216DF00-2627-424D-859B-39F0A250531F.jpeg726E63BF-1B3A-4313-9A80-1B878CB973FD.jpegGearcase pictures also

[EuropeanAM]

Verado-Style gearcase, which is suitable for this engine. Running a bit low on skeg material, though.

Two of the upper plugs pictured appear to be heavily fouled. If you're going to keep these plugs in the engine, I'd pull them again for inspection after a nice long (10+ minute) run in the 3500-5000 RPM range.

[Gotfish?]

Went back to lake today to test after replacing all plugs, still idles rough and wouldn’t go over 1500 rpm trying to take off, very sluggish. Loaded it back up and took to service center they hooked up and said I had an overheat fault at 181 degrees 0.5 hour prior which makes sense that is when it bogged down last time and started all this. He said no faults showing though and cleared all codes/previous faults if I’m saying that right. He hooked up a set of gauges and said fuel and air pressures were good, said one was within 10% of the other as required. He did replace fuel filter because I haven’t previsouly but said old one looked good and didn’t have trash in the system there. They would have to schedule me back for further diagnosis but tech was very nice and said check coils because there are no faults but it just sounds like it has a miss. I unplug injector plug at each one and #3 didn’t change how engine was running when I disconnected it, all others did. I changed coil with another one and it was still number 3, did same for plug and fuel rail injector(red top) and all same just on #3. Does this mean #3 direct injector is bad?

[JOE54]

no it doesnt , swap direct inj 3 with number 5 see in problem follows #3 swap to #5 cyl and #3 starts working , hurry up im late for supper

[Gotfish?]

I was somewhat concerned on moving direct injectors, is it as easy as sliding back fuel rail and swapping the direct injectors, buttoning fuel rail back up and then seeing if problem moves like you’re saying?

and go eat your supper, I won’t get to doing this until tomorrow!

[JOE54]

yep pretty much be careful of orings on DI and dont overtighten rail , you did do a compression test didnt you ?????? on number #3

[JOE54]

I was somewhat concerned on moving direct injectors, is it as easy as sliding back fuel rail and swapping the direct injectors, buttoning fuel rail back up and then seeing if problem moves like you’re saying?

and go eat your supper, I won’t get to doing this until tomorrow!

i hate MUTON , BAAAAAAA

[Gotfish?]

Swapped direct injector 3 and 5; issue stayed on #3. I have not had compression test but looks like I’m at point it’s going to have to go in for compression check and borescope I’m assuming on cylinder 3. I’ll see what I can get scheduled to drop it off, I’ll see what recommendations I can get for service nearby.

[JOE54]

compression gages are cheap , might try it yourself , always check basics first