Shifting in Gear with Motor Off or On? - 2.5 Merc Sportmaster

Hey Guys,

Do you shift in gear or turn off, shift and restart the motor in gear? I have been turning off and starting in gear. Seems to be so much easier on the lower. How about you guys? Is there any harm in starting in gear?

It's the only way to do it. Gear case will live longer.

Rock

I generally do not reply to post, I just read and learn and make my own decisions, but this one I think I can help a little with.

Yes, no doubt the gear case will live longer that way, but not always needed to be done that way.

I had a "STOCK" 2.5 - 200hp SuperMag with the SportMaster case. 20 years and 500+ hours on it, on my GrandSprort Ski. We skied with this for many years, and you know the in and out of gear it takes getting the slack out of the ski rope, and starting and stopping for hours while skiing. Never had a problem with the gears shifting while motor was running.

Then, the last year or two, I had to have the motor rebuilt. So, like many, I wanted more performance and had JSRE build me an AWESOME motor!!!!
That's when the problem started with shifting into gear with motor running. The motor would no longer idle at the low stock setting and stay running when put into gear with my 30" prop. Maybe it just needed a little adjusting, but I am not a motor guy, so the easy way was I turned the idle up to about 900 rpms and that worked. That worked, but I could really tell that it slammed into gear with higher than stock rpms. Most that I see doing the shifting with motor off, then re-crank in gear, seem to be at high rpm idle.

So I can see why the "turned up" motors would need this, but on a STOCK motor, I do not think it is needed. And of-course it is a safety issue, as I am sure some will point out. But if you are the only one running your boat, or have others know about it, then fine, its your boat.

Keep shifting them with the motor running please :D

The main reason for the starting in gear is the hi pitch props we run to go fast. A ski boat with a 17p prop would not have the same shifting stress as a 30p prop puts on the internals.

I’ve never chunked one in gear with motor running , I always start in gear !!!

The mechanical action of shifting into gear does not know what size the prop is on the motor. The prop is not turning and when it does turn, then it is already in gear.

After it is shifted into gear, then it is directly dependent on the RPM's of the motor to stay running or stall / kill the motor. Small prop, does fine. Large pitch prop, the motor on STOCK idle setting can bog down the motor and sometimes stall it. My 2.5 was like this. My 300xs motors do not have a problem at all staying running when shifting into gear at idle with very large props on it, and 1.62 gears. Maybe cause of the higher torque on the 300xs.

I ran 32" props on my 2.5 motor on my Allison, and right after shifting into gear, I would tap the throttle some to keep it running at idle. Much easier and safer than starting and stopping the motor all the time. I am sure it is something that you get used to doing after awhile. Just like I got used to adding a little throttle after shifting into gear. It is nice to be able to pull up somewhere and idle and then if needed, shift back into gear. With STOCK motors, I do not see where it is a problem. Yes, I am sure they would last much longer and when the gears do fail, it would be told that it was not from shifting in gear.

"RACE" motors with high RPM idle, then of course you need to crank in gear.

I'm no expert. Only been into hi po boats since 1976. Have had more boats than I can remember. The big props shift harder.

Up to about 24 or 26 pitch thru-hub props I will shift at idle. Over hub props I usually kill it regardless of pitch. The greater blade area and pitch do increase the load on the lower when shifting at idle...

When shifting your lower you have the pinion, forward, and reverse gear all spinning and the shift dog sitting still attached to the prop shaft. When you move the dog you are basically putting a square peg in a square hole. Common sense should tell you shifting with nothing moving will be much easier on the case than shifting at 500 rpm. And as stated above big props DO shift harder.

Rock

Nope, don't shift unless its an emergency. Start in gear, like anything else if you do it enough, docking and moving around other boats isn't really a problem you get used to it. First thing I checked on this Euro, was the neutral safety switch to see if I had to disconnect it.

Mercury Hi-Performance didn't start them in gear when they tested them, they shifted the hell out of them with the engines running... like 40,000 "engine running" shifts on a sportmaster with absolutely no issues. They're designed to be shifted with the engine running. :thumbsup:

A mercury dealer/master tech/factory sponsored racer is the one that got me doing it......Nothing that says you can't....Personal choice as usual.

I'll print off the report on some of our crabbers that I can pull shift counts. Guys that go 50 feet, shift to R to stop N to pull F to next pot repeat for hours a day every day. One guy has 14,000 hours on his 150 doing this. We just had to reseal his case. Everything else looked great. I didnt even think to look at the shift count


Now hi performance large pitch props. Sure.

Just make sure you use your trailer transom saver.