Idling with i/o tilted way up - bad idea?

[uncleslam]

Hi All, I have an Alpha 1 / Merc 5.7 on my old Glastron cv-23. In order to get to the lake next to my home (St. Paul, MN) from the boat ramp, we have to pass under a bridge that has some rocks that like to ding my prop from time to time. If I tilt the i/o all the way up and idle through this short 100 ft section I don't have any problems hitting those few rocks. But somewhere I thought I heard that running, even at idle, with the tilt all the way up is bad for the u-joints and or bearings, etc? Is there any truth to that?

Thanks, Mark

 

[Haut Medoc]

Re: Idling with i/o tilted way up - bad idea?

Welcome to iboats......
Yes there is truth to that......
You should never run the engine with the drive tilted beyond the 'green' range on the gauge.....
If you are using the trailer switch to go higher than the limit switch allows, then you are in dangerous territory........
It puts excessive pressure on the bearings, & it will fail eventually, possibly catastophically....
When?
Only the wizard knows........​

 

[uncleslam]

Re: Idling with i/o tilted way up - bad idea?

Is it really that bad for the i/o, even if it's only at idle speed for a 100 ft? If so, that means I have to drive to another lake.

Thanks, Mark

 

[Coors]

Re: Idling with i/o tilted way up - bad idea?

If the drive is all the way up, isn't the prop out of the water?

 

[DHPMARINE]

Re: Idling with i/o tilted way up - bad idea?

Way bad idea.There is a shaft between the outdrive and your engine that has two u-joints to accomandate the trim angle.Look at your boat and the drive at trim limit.do you trust those u-joints at full tilt ?

Maybe let the boat drift thru.If a u-joint lets go,it can break an $700 bell housing.If more happens,just price a transom plate.

Wow that's a hard way to say NO

DHP

 

[dave68iou1]

Re: Idling with i/o tilted way up - bad idea?

Welcome to iboats......
Yes there is truth to that......
You should never run the engine with the drive tilted beyond the 'green' range on the gauge.....
If you are using the trailer switch to go higher than the limit switch allows, then you are in dangerous territory........
It puts excessive pressure on the bearings, & it will fail eventually, possibly catastophically....
When?
Only the wizard knows........​

Should I have a limit switch? The trim was relocated to above the dash and I'm not sure how high I can lift it while in shallow water.

 

[whywhyzed]

Re: Idling with i/o tilted way up - bad idea?

100 feet? that's about 5 boat lengths....could you not just aim for it about 10 mph and shut the engine off?