2004 Glastron Merc 350MPI I/O need holeshot

[robertsmau]

I went skiing for the first time with the new boat and it won't pull me up on one ski. Here's my details:
- 2004 Glastron GX205 w/ Merc 350 MPI 300hp I/O
- Bravo 1 outdrive
- RPM ?? tach not working
- Top speed untested because kids cry, I won't really ever go open throttle
- Quick silver 1920P23 Al 3 blade prop
- Previous police boat bought at auction but the prop was new, did they put some junk on for the sale?

Options?

 

[fossill]

Re: 2004 Glastron Merc 350MPI I/O need holeshot

Fix the tach, leave the kids at home during sea trials, get a gps to check top speed. I'd then get a suitable high 5 if your budget allows or a quality 4 blade.

 

[robertsmau]

Re: 2004 Glastron Merc 350MPI I/O need holeshot

It may be a while before I can get the time to fix the tach and get out on the water alone. One quick question in the mean time. Would a 23P prop not give a good hole shot because the motor can't turn it? My motor would spin the prop without a problem but start to cavitate. Will a 19P reduce cavitation? What other factors should I be considering?

 

[steelespike]

Re: 2004 Glastron Merc 350MPI I/O need holeshot

As suggested we really need a base line test with the max rpm and speed.Also the rated max rpm usually on a label on the motor.
While a 23" pitch may not be ideal for skiing I think it should get you up.
Ex police boat My first thought is it may have a zillion miles on it some of them rough.If you get us those test figures we can tell pretty easily.

 

[robertsmau]

Re: 2004 Glastron Merc 350MPI I/O need holeshot

It does have 740 hrs but I did a compression and leak down test and everything was within specs.

 

[jkust]

Re: 2004 Glastron Merc 350MPI I/O need holeshot

A 300hp Glastron should rip your arms off. It should turn a 23pitch with ease while yanking you and several friends up. That is a light boat with high hp. Any other symptoms? That GX is 125lbs lighter than my 18footer and I can't even imagine the effects of having 100 more hp. You should be able to access the data to see exactly how hard it was run being it is an mpi.

 

[fossill]

Re: 2004 Glastron Merc 350MPI I/O need holeshot

740 boat hours is a lot of hours, especially if it was a police boat.
I bet that engine is feeling tired.

 

[msojjo]

Re: 2004 Glastron Merc 350MPI I/O need holeshot

I have the same motor in my 20' boat, but my boat is heavy as hell, almost 3500 with fuel. I purchased the boat with a 22 pitch four blade and had a hard time getting out of the hole. My rpms were down around 4000 so i had 1000 rpms to make up for. I went down to a 17 pitch three blade, and my rpms are where they should be and i can pull up a skier with 8 people in the boat. But you do need to find out where your wot rpms are at before you start changing props.

 

[180shabah]

Re: 2004 Glastron Merc 350MPI I/O need holeshot

740 hours is not a lot for an I/O that has been maintained. It should easily run 2000+ before rebuild time.

As mentioned, we need WOT numbers to procede with any recomendations. You may never run wide open regularly, but you need to in order to get you boat dialed in. But first, comes the tach.

Yes a 23" prop is a lot of pitch for a single ski, but with out WOT numbers, we don't know what is safe to suggest.

 

[jkust]

Re: 2004 Glastron Merc 350MPI I/O need holeshot

740 hours is not a lot for an I/O that has been maintained. It should easily run 2000+ before rebuild time.

As mentioned, we need WOT numbers to procede with any recomendations. You may never run wide open regularly, but you need to in order to get you boat dialed in. But first, comes the tach.

Yes a 23" prop is a lot of pitch for a single ski, but with out WOT numbers, we don't know what is safe to suggest.

I'm suprised nobody besides shabah jumped on this earlier. 740 hours for an 04 my seem on the high side of average but for a patrol boat it seems low to me. As most will say on here, it's not how many hours but how well it was maintained. Because it is an mpi, you have the benefit of bringing it into a dealer and they hook it up and can print out some nifty info that is not available to carb engines. I know I shy'd away from newer boats with less than 200 hours that were MPI as I felt the price should have been lower. (our boats in MN generally have pretty low hours due to our insanely short season). A boat that size with a 350mpi would've changed my tune. Why don't you also post some pictures so we can get a good look at it.