Vision 20 + OS motor set-up tips

[ozbryan]

Tim, Hate to see ya struggle buddy...........

Did have one idea thou,check your servo horn for stripping on the shaft splines.

I had one drove me nutz till I found it. Sometimes I had WOT, Other times I didnt.

Good Luck Man,

Gene

Interesting thought Gene.. I had been thinking maybe the throttle isn't opening correctly aswell as this thing sounds like it wants to go but just can't.

 

[Tim_Duggan]

We're on the same wavelength, Gener!

I had the same thought & checked that at the pond on the weekend. All good. I even swapped carbs thru the day and had to set linkages up again. Also thought maybe the mix servo was doing the same thing so flowed it. It's not too rich, I could lean it to the point where it would stop. The plug looked slightly pulled and had the gloss taken off the element ever so slightly. Could run it empty without the big increase in rpm just before it ran out of fuel. Longer pipe made no difference either.

 

[Tim_Duggan]

Hadn't thought of trying that Greg, so I just gave it a shot. Flowed the same when going into the pressure side of the tank & through the needle and carb, as what it flows through the needle on it's own.

 

[Tim_Duggan]

Checked the silicone tube and pipe fitting also, both ok

 

[David Moyle]

Tim... What are the details of the GO? What crank is in it?

 

[Tim_Duggan]

Lights crank and PTO Dave. Different engines with another Lights crank or Tecno Long stroke crank do the same on this boat.

 

[kesso2118]

Tim,

I know this is a "long shot" but have you checked whether the transom on the boat is perpendicular to the sponson ride surfaces?

When I was experimenting with packing the OS Mounting Plate to change the steering pin angle on the Breakthrough Tunnel I found that with the bottom of the plate packed out the nose of the boat was held down as soon as any rudder was applied.

To get the best straight line speed I needed to point the boat and then let it run. Even the slightest use of rudder to adjust the straight line direction would affect too end speed.

I don't know whether the Vision would behave the same way but it sounds like you have tried everything else??????

Good luck,

James

 

[Tim_Duggan]

Hi James,

I can confidently say that's not whats going on. It doesn't matter whether I drive at a gentle arc or go straight. In fact the boat does everything right handling wise - it's very nice to drive.

Switching over to a "Sport" OS set-up with it thru the week. Will tear the mod motor and lower part and have a good look while it's off.

 

[Tim_Duggan]

Fuel is ok. Definitely has nitro in it! Lol. Starts too easy!

 

[Ronald van Essen]

Tim,

going through very old topics I came across this:

seems you asked for setup a while ago as well:

http://www.intlwaters.com/index.php?showtopic=56707

some more info:

http://www.intlwaters.com/index.php?showtopic=57096

 

[Tim_Duggan]

Thanks Ron,

Yes, previously I asked for set up notes for a mod boat and got some great answers. That's why I thought I would ask for some notes for a sport / stock set up also. Saves lots of time at the pond, where I am usually busy running races etc.

The boat in question now has my OS on it for this coming weekend.

 

[Tim_Duggan]

Ready for testing this weekend. M440 prop, zero trim angle, CG @ 7 3/4", bullet 1/8" above board.

 

[Slideblues]

Lookin good Timbo,

Hey just for grins ya might try yer Zman 1440.

If that dont rev out the stars are outta line :lol:

Have fun,

Gene

 

[Tim_Duggan]

Ran well with the OS once I found a needle setting it liked. Bullet at 1/8" above worked well but tried it a bit lower and got better drive.

The OS was making that nice transition on throttle when you get them close, prop wise.

 

[Slideblues]

Any progress with the mod motor teardown and inspection ?

A head scratcher fer sure..........

Gene

 

[Tim_Duggan]

I ran it again today with the OS. I really like it as a Sport boat and am going to keep it in that configuration.

The timing numbers in the mod motor have some wild numbers. Haven't tested it yet after taming it down some.