1991 2.5 200 V6, 3rd times a charm?

[sangerbarefoot]

good morning gearheads!

After sitting on the bench 5 years (long story) my V6 is going back together. This is the 3rd time it has been apart. First overhaul by Dick Sherrer Marine in 1997, then again by Dick's under warranty after it seized a few hours after they overhauled it.... "we did not replace the thermostats at overhaul, so you have to pay for the thermostats" This taught me finding the cause of failure was not their strong point....

This time it lightly seized the top two port cylinders after a oil line for the injection broke under the cowling in 2011, ruining a week long Nacimiento lake trip.

I am toying with removing the Oil Injection, I have the factory Mercury 43453 block off shaft and O ring, the question is the pictured crank gear. I have read that removing it will cause the adjacent cylinder to run "Lean"... I don't know how leaving it will hurt anything... and I have not decided to junk the oil injection system just yet.... It's a family water ski boat and never sees the 6,000+ rpm problem zone (from what I have read).

Leave the gear or remove the gear??

[ChrisCarsonMarine]

Leave the gear,it helps keep the volumn in the crankcase on its cylinder closer...it's still somewhat bigger.Loose the oil mixer,This isn't oil injection unless you count injecting oil into fuel flow as injection.Be sure to use the blockoff factory part,it not only also takes up crankcase space but also keeps the brass bushing from falling out of the number 2 cylinder base...not a good thing to have happen,Chris

[sangerbarefoot]

thanks for the confirmation.... now a new problem. One of the eight (#3 in the book torque sequence) 3/8-16 bolts that hold the front half to the engine block (retains the crank to block) would not take the book torque of 35 lbs. it stripped / pulled the threads out of the block at 25 ft lbs. so I took the front half back off, cleaned off the loctite 518 and now am in search of a helicoil to fix the bad threads.... not the end of the world after 5 years of sitting, but I was on a roll!

fingers crossed no other bolt pulls it's threads at the second assembly after I helicoil the offending hole.

[sangerbarefoot]

I ended up using a helicoil in the block on #3, then installed 4 studs instead of 4 bolts for positions 1-4 to secure the front half... I just did not like the look of the threads in the block. McMaster Carr grade 8 hardware to the rescue! The head torque went fine, all at 40 per the book. I'm waiting for some air box screws, an impeller and the special mercury hose clamp / zip ties to finish it off. I reset the timing indicator with my JSRE dial indicator, it was off 2 degrees.