eclozon

Bought a vegas, loved it , wanted more. I built a Hawk 3.5 outrigger with a new os .21vz-m. I put it in the water and it starts to take off and then just boggs.
It looks like it won't pull the prop. It will stay running if you don't open the throttle more the 1/4. I am using a MACS pipe with a 180 header. The pipe has not been cut, it's almost 11" fron center of piston to the weld at the widest part. The prop is a s230 pranther. I am guessing the pipe is too long but I don't know where to start from.

Anyone have any set up tips for this engine, pipe and hull and prop?
thanks
Ed

Dan S

Pipe is too long, start from 8 to 9 inches.

230 prop may be too much but since I don't know about riggers the prop may be ok for riggers.

Dan.

f16man

Yup 8 1/2 to 9 1/2 '' inches should be the length also how fat are you running the hs needle, I would start at about 3 turns out and go from there, maybe raise the prop a bit.

Jerry Dunlap

Prop is WAY TOO BIG. On my Sp 20 w/O.S. VZM I'm running a X-437/3.

JD

f16man

O boy I blew it with the hs needle setting os says 1 1/2 turns out to start with, sorry about that.

eclozon

Thank you Jerry.
The kit instructions list several props, I was able to find a 1455, x548 and the s230 at the local hobby shop. Do you think any of these will do. I set up the outrigger for oval, with the rear sponsons on.

The motor only has about 5 minutes on it so far.
thanks
Ed

piper_chuck

My Feedback: (12)

Those props still sound big. I run a 1455 on my sport 40. The Octura prop chart suggests the following for a .21 rigger: 1450, 1650, 1945, X447 X447/3, X448. On the Prather side, they suggest 220, 225, and 230 for a .21 rigger. If you have everything setup perfectly (engine broken in, mixture right, pipe length correct, and a good launch), you might be able to run with a prop at the high end of the size range. When you are just starting out, go with one on the lower end and work your way up as you get the other factors dialed in.

If you haven't already done so, it would be well worth calling Gary Preusse (G&M Hobbies). Here's some info from them on your boat: http://home.earthlink.net/~jpreusse/hawk/setup.html . Their number is at the bottom of the page.

gooycheese

1455 and 1457 I run on a Hawk 7.5 . Try something like a 1450 cut down or maybe a 220 prop I heard those are good for a start.


Paul

Ron Olson

My Feedback: (1)

Mac pipes out of the package are always too long. A tubing cutter does a great job of shortening them. Generally pipes are shorter on 'riggers than they are on other hull types but start out with it a little long.

misshydro

cut off about a 1/8 at a time until you find that sweet spot! then you motor will go like a rocket!![8D]

eclozon

Thanks all

I cut the pipe and tried the s230 and the x548. I tried the high speed needle everywhere between 1 and 2 turns out. The boat takes off slow does about 10 mph and dies after a few hundred feet. I have tested the plumbing, no air in the fuel line. Runs fine out of the water. We launched the boat about 20 times and pulled the prop up to about 1/2 inch. Still end up with the 10 mph top speed and no revs. I will have to make a drive to try to find one of the props you suggested. I am kind surprized it won't run at all though. Although I am new to boats, I have tons of experience with nitro engines. I am running 30% nitro, it sure feels like something strange is wrong.

thanks again for everyone's help
Ed

mopartybob

I can't believe that the tech notes and manual(pg.20) call for a setting of 1 1/2 turns out only....[:-],open it up to 3 turns out,(per F-16 guyz rec.)keep the igniter on it till you can blip it to mid-throttle...have you tried that...? [:-]

eclozon

Yes, I know it supposed to be on the fat side out of water but after about two turns out you can't get it to clear up enough to take any throttle at all. I am starting to think maybe the motor just doesn't like water. I also took off the water feed to try and get some heat into the motor, it never got more than warm to the touch ~100 deg, of course it never ran for more than a few hundred feet either.

I sure hope a new prop does something. The 39mph I get out of my vegas is looking better by the minute. My brother was able to squeeze 42 out of his vegas. He has the older version 1. I think the smaller cable atnd stuffing box on the earlier version account for the speed difference. (that's my story and I am sticking to it) We both run OS .18's with MACS pipe and use radar for tuning. I have run 7 gallons through the OS without too much problems and I thought I had a clue on how to make these water thingies at least go forward.

So far I have spent two days at the lake on this boat alone. I have managed to burn almost 4 oz's of fuel, pretty sad.

thanks agian
Ed

misshydro

The manual might be wright?[&:] My thundertiger MX-R pro.21 manual said 2 1/2 turns out and man that motor was flooding out on me.[:@] So I looked at the O.S setting 1 1/2-2 turns out and it worked on my motor.My.21 was the same thing 1 1/2 turns out[8D].Do like Mopartybod said then start to turn in the screw until you get it to run wright. Plus remember were in the cold seasion and nitro motors need to run more richer with cold weather. If that stuff dont work get another carb!! I heard from acouple of guys that that carb is pain in the but to dial in.[&:]

TheRealDeal

Ed,
You might want to try getting a full tank thru the motor on the bench before going out again,,,Are you useing a Hot plug?

Where are you at in Ca.?



Joe

mtruex

i had the same problem running this engine in a cat until i went smaller on the prop..it does not like to turn a lot of prop..

Ron Olson

My Feedback: (1)

Go with a 37-40mm prop, what you have there is way too much.
Carb settings will vary according to the manufacturer as the threading can have different pitches and diameters on the needles.

Mike Nowicki

I would try a octura 1445. You need a lifting prop to get the rears up asap.

eclozon

No, it's a medium P7. Some bench time sounds like a good idea, I'll fix up a water bottle and get some fuel through it.
I am in Castaic, by Magic Mountain. As soon as the hobby shop in van nuys opens, I am going to try and find a smaller prop. Are you a member of the Pond Rats? My buddies and I want to join that club. We wanted to go see the club races yesterday but elected to take the boat to Castaic Lake, bad choice.

Ed

JWMods

That big 10mm carb on that engine can make ya nuts too,, especially with a large prop. Large bore carbs
work well with racing applications but for sport use they can be a nightmare.

I haven't ran the VZ-M in a hydro, I adapted it for O/B use on the Thunder Tiger lower unit.
Even after sending the 10mm carb to a friend in Australia to have it reworked it still gave me fits.

I modded the O.S.21XM O/B carb to fit the VZ's deeper case throat and I still use it to this day, in an O/B.

The VZ-M is a "race timed" engine right outa the box and usually those type engines require smaller/pitchier
props,, JD runs a 437-3,, I run a 640 cut down to 37.5mm in my o/b engine,, I think most of your solution
is in that area.
also, I don't think bench running is going to help much, these engines run so differently between the bench
and the water that it makes that exercise moot.
JW

topfuel4430

My suggestions would be go to 8.5 inches on the pipe, get roughly a 42 mm prop, good fuel of around 50% and a cold plug (MC-9 or equiv)and find your needle with that. The world of riggers can be much more difficult, especially if you starting from scratch. The smallest amount of adjustment on your strut and sponsons will make or break you. You said you raised the prop a half an inch (???) thats a LOT, and unless you were completely off on the set-up, you should never have to move anything that much. How is the boat set up right now?

~James

Ron Olson

My Feedback: (1)

Getting confused? Me too. I know Mike Nowicki personally (Hi Mike and welcome to the site!) and Mike knows 'riggers. Jerry knows OS engines as well as anyone else in here. Sometimes you just have to try different props to see what your boat likes. I go through that every time that I throw another boat together.

eclozon

Hi James
I have the strut depth set at 3/4" bottom of the boat to centerline of shaft, with neg 1 degree (back down). The pipe is sitting at 9 inches, I was going to fine tune after break in. (may be a while) The sponsons have one shim in the back and none in the front. I moved the prop all the way up just to see if I could get the motor to spin.
Ed

TheRealDeal

Hi ED,
I think the O.S. motors tend to like hotter plugs then most others,a hotter plug will help with a fatter needle and lower nitro%,,A smaller prop will be necessary too,the general rule of thum is to start small

I'm going to renew my membership in Camarillo next month,It's a great club and perfect weather year round and you gota love the covered pits in the summer!,,I like to run during week,weekends can get pretty busy in the summer,I drive a White Tahoe on Boggers (can't miss it!)if you see it there say Hi,

Joe

ralph289

Everybody is going to have a different answer to your question. what works for one boat may not work for another.
This is my set-up on my 3.5 Hawk and it WORKS for ME but maybe not for you. HSN 3 turns out (remote needle), strut 1" down from the tub, FLAT prop angle, 60% nitro, ABC H-5 (reworked by Mark Sholund Props4U), Jim Irwin Quiet Pipe, OS .21 RZ-M. Will also pull a ABC H-7 prop, MC-9 plug.
Handles like a dream and FLYS !!
Ralph