85 VIP Performance????

[steve147]

Last fall I bought an 18' '85 VIP and completely re-did the interior, and metalflaked and clear-coated it. I took it out on the water for the first time this week, and discovered a few small problems which are an easy fix, my question concerns performance.<br />The 140 horse inboard Merc seems hard to start, idles rough, dies occasionally on throttle shut-down. The plugs are clean, fuel filter good, wires not bad, but it DOES have points, maybe need filed???<br />I know it's a heavy boat, but is 42mph an acceptable top speed for this rig? <br />Thanks to anyone for any info you can give me, I'm just 'moving-up' from a little 14 footer with a 60hp outboard....<br />Steve W.

 

[DJ]

Re: 85 VIP Performance????

steve147,<br /><br />42 MPH is an excellent turn of speed for that 4-cylinder.<br /><br />I wouldn't file the points, I would replace them. Condensers too.

 

[steve147]

Re: 85 VIP Performance????

Thanks, DJ, I'll try replacing the points/condensor and see if it smooths-out and starts easier. I guess I'm just comparing the top-speed issue to the little 14-footer with the 60 hp outboard, it tops at 33 mph and feels like a go-cart, comparatively, the new boat feels like I'm driving my living room around the lake!!!<br />Any idea what pitch prop I should be running? I plan on using mainly for pulling wakeboards/tubes.<br />Thanks again, Steve W.

 

[DJ]

Re: 85 VIP Performance????

Prop it to turn around 4600 rpm at wide open throttle-light load. THat should be best for all around.<br /><br />Start with that as a base point. You can drop an inch or two in pitch if you are going to be dragging a lot of things around with a loaded boat.<br /><br />One inch in pitch generally relates to 200 rpm-up or down.

 

[steve147]

Re: 85 VIP Performance????

That would make sense.......while I'm running 42 mph wide open (no load, just me), I'm only turning about 4300 rpm, and it doesn't feel like it really pulls from a stop (the prop has an old motorcycle sprocket as a washer, so I KNOW it's NOT stock.....).<br />So you think maybe an inch smaller pitch I'll have more "umph" but a lower top speed???

 

[DJ]

Re: 85 VIP Performance????

steve147,<br /><br />You can probably drop a couple of inches. You may be surprised that your top speed may remain pretty close.<br /><br />Get the right hardware on there too.

 

[steve147]

Re: 85 VIP Performance????

Wow, you were absolutely right.....I checked the numbers on the current prop, and it's a 21 pitch, so a 19 should put me at ideal rpm. Thanks again, Steve W.