Forward/Reverse switching directions vs. RPM

I

imspacemancraig

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Wasn't sure how to title this one. I checked through my manual and haven't found anything on this, but talking to another old boater about my transmission problems and he said some boat engines you aren't supposed to switch gears with the engine running above 1000 RPM and some have a warning light to warn against it.

I have an 86 Mariner 3297. I don't see anything about that anywhere but thought I would ask. My engines are tuned to idle at about 700 RPM. In a no wake area I am just under 1000 RPM to keep control, but barely.

Thoughts? Almost sounds like a rookie question, but I haven't heard this before. Obviously you wouldn't change gears while revving really high.
 
I never like to change gears at anything more than idle speed.
 
700 rpm. Never change gears above that unless you have to.
 
nothing above idle you'll break things at worst at best you'll shorten the life of your trannies..
 
and you know you can use the props to turn the boat at low speeds ? We have small channels here that it takes rudder and prop changes to stay in them..
 
It was more of a hypothetical situation for the control part. The original conversation came up because I did blow a transmission. Now in search of a replacement. I am told that both of the transmission and the gear case need to be replaced. Not sure exactly how I did this, but guessing this isn't going to be cheap. We were riding along without any issues on plane when it felt like the port engine dropped out of gear. I looked down and no power on the port side. So brought the engines down and the port engined stalled and limped back on one.
 
On my older boat the Walter V-Drive warning light comes on at something like 1200 RPM and below. I try to switch gears well below 1000 RPM, however on those rare occasions when its really windy I might be tempted to idle just a wee bit higher, right around that 1000 mark. Its not the healthiest thing to do for the V-Drives but it hasnt cost me anything in all these years.

My older boat (the '75) didnt respond to the changes in direction of the twin screws when maneuvering as well as my '80 does. The hull was the same so I dont know why - maybe different props. Or maybe the skipper just got better at it! But I'm told by others who have taken a turn at the helm on my boat that it does indeed handle very nimbly in docking maneuvers. I can even reverse with a teeeeeny bit of directional control on one screw!!!!!!
 
did you find water in the trans oil? that is the most common cause of trans failure.
 
PBardunias - I think that is what I have as well attached to Velvet drives.

pdecat - I did not remove the transmission myself. Had a mechanic do it and take it to be looked at. They didn't say anything about water in it, but did say the oil was burnt and when I heard back from the trany place they said the insides were blue so they could tell it heated way up.

The mechanic I had remove it said his theory is that the water intake hose was crimped and therefore not enough water was getting into the system to cool things down and then the trany began to heat up, burn oil, and eventually locked up. They believe the engine itself is OK, but looks like the trany is a goner... So the hunt begins for replacements now...
 
he likely means "transmission oil cooler", a "radiator" for the tranny.
 
I'm late to this thread, but my manual says not to shift over 1000 RPM (454ci Crusader model 350s w/...dang, don't remember what model tranny). If maneuvering in low wind (inland lake, no tides, currents, etc.) I stay around idle at 700 RPM. If more than about 5mph winds and backing into my narrow slip, then I increase to about 900 RPM to give more control authority. Else my 3607 can be slow to respond to directional inputs using the transmissions (ie. rudders straight, steering with the transmissions only).
Good hunting!
Jeff
 
Just did that last year, had to replace the v-drive case the inner bearing support race was cracked.
Entire job by the marina about $8,200 ouch.
Good Luck
 
Ya, looking like that much for me. Waiting to hear if the case is OK or not and if it can be rebuilt. Looks like the tranny can be rebuilt, but not sure on the v-drive yet. Month of August is shot, hope to have it back for Labor Day to get a couple weekends more before winterizing... :(
 
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