17 ft Glastron with a Volvo I/O

[Bill kubiak]

Got the small 4 cyl volvo and the boat will hit 40 MPH. but it feels bow low. if I trim the LU up to raise the bow the steering becomes scary and I have to hold on with all my might to make it go straight and when i do that the boat speeds up more, if I trim the LU down to where there is no pressure on the wheel the bow seems too low and the speed drops a little. What is happening?
This has a teleflex push pull steering system.

 

[jevery]

Re: 17 ft Glastron with a Volvo I/O

Sounds like you're trimming up a little too high, while a little faster due to less wetted surface on the bottom of the boat the top of the prop is probably starting to break the surface resulting in a lot of sidewise torque on the lower unit - thus increased feedback to steering. Trim down to where steering is more neutral - the "low bow" feeling shouldn't last long.

 

[Frank Acampora]

Re: 17 ft Glastron with a Volvo I/O

Did you try to adjust the trim tab on the lower unit? The amount of force it exerts at a particular setting is only good for a small range of lower unit in and out trim. SO if you are looking for the performance at the highest speed available from your hull, set the trim tab so that steering is neutral at the trim in or out (up) setting that gives maximum speed.

You should then notice that when trimmed in for hole shot, the steering will become very heavy and will improve as you trim out (up)

If the problem persists and money is no object, buy a no feedback steering helm. Or if you are really rich, buy a hydraulic steering system.

BTW: That's my little 1971 V153 Glastron in the avatar. 42 MPH with a Chrysler 90.

 

[thrasher]

Re: 17 ft Glastron with a Volvo I/O

I think you are doing really well to get 40mph from a 3.0L engine. I have a 19foot Glastron with the Mercruiser 4.3L and can only get 45mph (measured with GPS) from it (with 2 adults + 2 kids onboard). I don't know what your problem is, but it can't be too serious if you are getting that kind of speed.

Gary

 

[Texasmark]

Re: 17 ft Glastron with a Volvo I/O

I had 2 friends with Glastron/I4 Volvo packages. No offense, but didn't like either. For the name that Glastron carries, that parred with the Volvo engine/outdrive just didn't get it in my book.

In agreement with Frank's comments. My version:

Don't remember if that outdrive had a trim tab or not. I don't recall it having one. If you had one and adjusted it properly, you could better control your steering when trimmed out where you belong. I say "where you belong" because the only time you want your boat plowing (trim sucked in, bow down) is when that is the only way you can get a smooth ride. Because, just as you said, your speed suffers and your fuel gph does too.

The effect of propeller thrust on steering is trim (angle with the water of the prop) sensitive. Most of the time you (I) set the tab for the easiest steering where I do the most running. Some rigs have a broad range of control and others it's pretty narrow. Changing prop pitch can affect it also, with the higher pitches being the hardest to control.

A "no-feedback" steering system by Teleflex-Morse (different than standard systems they produced) would help the wheel to stay put when you are having to wrestle to hold it on course.

My 2c,

Mark

 

[Frank Acampora]

Re: 17 ft Glastron with a Volvo I/O

OH, Yeah! I was thinking Mercruiser. Volvo had that odd shaped exhaust snout--don't remember if it was adjustable or not though --and they had a real clumsy looking lower unit. But totally agree---In those days, Glastron/Volvo was not the best combo even though Volvo now has much improved their look (don't know about performance or longevity on the Duoprop)