Max trim up at idle speed?

[noclutch]

SX-A drive
When in the shallows at idle speed, how high can I have her trimmed up for bottom clearance without damaging anything? (U- joint or gimbal?)
I have a pretty good ear for things, so might the sounds of things back there whilst trimmed way up tell me if I'm OK? Will I hear gravley or rumbling sounds if too far up?

 

[aerobat]

Re: Max trim up at idle speed?

afaik you can go up to the redline on the gauge. anything above it is only for transport with engine off.

when it goes ugly shallow i would shut off the engine and row the last bit instead of concentrating on the point where you hear the u-joint rumble.

 

[noclutch]

Re: Max trim up at idle speed?

Hmm. I don't think I have a red line on my Farina gauge. Now I have started it a couple of times with the drive fully up and I think I heard sounds I didn't like and promptly trimmed down :/

 

[skydiveD30571]

Re: Max trim up at idle speed?

I have an sx-a and no lines on my gauge either. I have accidentally started it fully up before and you can tell the u-joints don't enjoy that.

The sx-a manual says running at 0?-6? trim and idle at 6?-29? trim is ok. According to Volvo drawings, max tilt angle is 52?. So if your gauge goes full up to full down, halfway should put you at 26? which is in the safe zone for idle speed. Now if you have an extended swim platform you might have trim limiters inside the trim cylinders that stop the drive at either 42? or 32? so the drive will not hit the platform. I have that but not sure which one. In that case, halfway on the gauge will be a little conservative. Better safe than sorry I figure. I've gotten into the habit of, whenever I sit down and put the key in and turn it to "on", I check that the trim needle is atleast halfway down before cranking it over.

When you want to speed up over idle speed, chances are you are in adequate water to do so, so trimming down won't be an issue.

 

[noclutch]

Re: Max trim up at idle speed?

Thanks skydive. Only up to 6* up- that's interesting- would have guessed much more.
Yea that start up rumble might also be aggravated because at cold start up it does seems to spring up over a regular idle speed for a couple of seconds. I do have an extended platform fwiw. I think I'll throw an angel finder on it while up in the garage, maybe check that against the gauge for the 6-29* points.

 

[Don S]

Re: Max trim up at idle speed?

You don't need a gauge or a trim limit switch. They both could be out of adjustment. The gauge, well you don't need one, they tell you nothing of importance.
You trim up until your speed slows down and your rpm's start going up. That means you are trimmed up too high so you need to trim down some for best rpm and speed. If the boat porpoises, you are still trimmed to high and need to come down some.

 

[noclutch]

Re: Max trim up at idle speed?

Thanks Don. So you're saying that underway with the engine idling I can trim up until the prop cavitates?

 

[Don S]

Re: Max trim up at idle speed?

Thanks Don. So you're saying that underway with the engine idling I can trim up until the prop cavitates?

Yes, that will be fine. No real reason to run higher if the props out of the water.

 

[noclutch]

Re: Max trim up at idle speed?

Ha, yea. No my prop would be far from out of the water- at full up angle it is well below the swim deck, which is just a few inches above the waterline. Maybe I'll post a pic or two tomorrow.