OS .21 vz-m won't rev
11-18-2007, 03:20 PM
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RE: OS .21 vz-m won't rev
ORIGINAL: 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 (on a sport 20),, 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
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 (on a sport 20),, 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
11-18-2007, 04:06 PM
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RE: OS .21 vz-m won't rev
Nice Boat! I noticed some collars or something next to the sponsons? I got a new handful of new props and I am out to give it another shot. I am feeling lucky, I'll bring the radar gun out to the lake and let you know how it goes.
Ed
Ed
11-18-2007, 05:08 PM
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RE: OS .21 vz-m won't rev
Yes it does have collars on the sponsons, makes them adjustable in and out and also easy to replace a sponson (I have an extra set).
Thanks
Ralph
Thanks
Ralph
11-18-2007, 05:38 PM
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RE: OS .21 vz-m won't rev
I have just installed a .21 VZ-M into a vegas and I had the same problems you having and in fact the engine was rather tight and sweaked when I turned it over a bit worrying but got better once it had loosend up a bit after about two tanks, the 1 1/2 turns did not work I had to lean it about 1/4 turn from the 1 1/2 before it would respond.
11-19-2007, 05:47 AM
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RE: OS .21 vz-m won't rev
Can any-one tell me what is involved in Changing the VZ-M carb with the OB Carb
AS I dont have a OS outboard carb to compare mounting Dia is there any bushing required ect
Peter T
11-19-2007, 10:40 AM
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RE: OS .21 vz-m won't rev
The XM o/b carb is the "20J", sells @ Tower for $67. The carb neck is the same as the one that comes
in the VZ-M (15mm) ,, But, the carb neck on the 20J is far shorter than the VZ-M case. I don't know
how well it will work with as a straight swap,, I made an extender (on my lathe) for the 20J to fit in the
deeper case throat. It delivered enough fuel to my VZ-M converted to O/B use for heat racing easy.
If I could figure out how to get a pic on here, I'd show it to ya[
]
Jerry
in the VZ-M (15mm) ,, But, the carb neck on the 20J is far shorter than the VZ-M case. I don't know
how well it will work with as a straight swap,, I made an extender (on my lathe) for the 20J to fit in the
deeper case throat. It delivered enough fuel to my VZ-M converted to O/B use for heat racing easy.
If I could figure out how to get a pic on here, I'd show it to ya[
]Jerry
11-19-2007, 10:47 AM
#33
RE: OS .21 vz-m won't rev
Jerry, there are 2 ways to upload a shot in here. One is to use the "Reply" button above ^ as that takes you to another screen. In the lower left corner you can upload files from your computer. The other is to use the "Image" button if you taking it from a picture hosting site and insert the link between the "][".
11-19-2007, 02:54 PM
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RE: OS .21 vz-m won't rev
Well, you were right. I put the smaller prop you suggested, put it the water and it took off. Made two laps at about 35 MPH, running rich went to turn back about 75 yards out and no response. The boat just kept going until it was out of sight. I turned the radio on and off, hoping to get the failsafe to kick in, nothing. We took the full scale boat and found it about 15 minutes later. It had traveled several miles and ended up on a rocky shoreline. The hull is crushed back to the gas tank, one sponson broke and the prop didn't make it. I was glad to see it run and all and I did manage to get a tank of gas through it but I don't think this boat likes me. I wish I knew what went wrong. The radio is a brand new Futaba 3 pm fasst, brand new zero time batteries. The steering and throttle failed, I thought the radio had a fail safe but I wasn't using digital servo's so maybe not. It has an antenna about 5 inches long on the reciever. I ran the antenna inside the side of the boat, maybe I should not have done that.... When I picked up the boat the throttle was open and it was out of gas. (transmitter long since off) I don't have any idea how long it ran. The motor still has compression and seems to be OK. The radio also worked fine, no water in the reciever baloon, no linkage problems???
I am sure I can fix the boat, the radio concerns me. Any reports of range problems or antenna issues?
thanks
I never give up, I just wish the boat knew that...
Ed
I am sure I can fix the boat, the radio concerns me. Any reports of range problems or antenna issues?
thanks
I never give up, I just wish the boat knew that...
Ed
11-19-2007, 03:57 PM
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RE: OS .21 vz-m won't rev
Your 3PM FASST system is equipped with a built in Failsafe for both low voltage and loss of signal, you must however program them for them to work (in case you didn't) and if you did it is always a good habit to test it before you launch.
Also I have heard and read in another thread that the system won't work if you add an external failsafe (conflict I believe).
Sorry for your boat.
Dan.
Also I have heard and read in another thread that the system won't work if you add an external failsafe (conflict I believe).
Sorry for your boat.
Dan.
11-19-2007, 04:23 PM
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RE: OS .21 vz-m won't rev
I had problems with the connector that goes from the battery to the switch, if you lose power to your RX then you have NO failsafe. Make sure your connections are good, on battery to switch and switch to RX.
Paul
Paul
11-19-2007, 07:53 PM
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RE: OS .21 vz-m won't rev
I'm so sorry to here that,,has happened to me with a 1/4 scale tunnel,, full throttle clear across the lagoon.
First time that boat didn't blow off at full tilt across there,, sometimes you don't get lucky I guess.
Again, sorry about your loss,
JW
First time that boat didn't blow off at full tilt across there,, sometimes you don't get lucky I guess.
Again, sorry about your loss,
JW
11-20-2007, 08:28 AM
#42
RE: OS .21 vz-m won't rev
I don't know about that particular radio but 5 '' reciever antenna sounds very short to me, also I don't think I would hide it in the hull. Check out your power switch real good too. sorry about your boat man.
11-20-2007, 09:51 AM
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RE: OS .21 vz-m won't rev
The radio is a brand new Futaba 3 pm fasst, brand new zero time batteries. The steering and throttle failed, I thought the radio had a fail safe but I wasn't using digital servo's so maybe not. It has an antenna about 5 inches long on the reciever. I ran the antenna inside the side of the boat, maybe I should not have done that.... When I picked up the boat the throttle was open and it was out of gas. (transmitter long since off) I don't have any idea how long it ran. The motor still has compression and seems to be OK. The radio also worked fine, no water in the reciever baloon, no linkage problems???
I am sure I can fix the boat, the radio concerns me. Any reports of range problems or antenna issues?
I am sure I can fix the boat, the radio concerns me. Any reports of range problems or antenna issues?
11-20-2007, 08:55 PM
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RE: OS .21 vz-m won't rev
I am using dry cells (4x1.5) so I should be good on that front. I did mess with fail safe. I seems that if you do not use digital servos you have to program the fail position. Ok did that. After reading a bit closer it appears you have to re-program it every time you turn it on. I confirmed it, shut it off and back on, no fail safe. I still wonder about the range problem, 75 yards just isn't enough. I am trying to find out more about the antenna mounting and what other people are getting as far as range.
Oh yea, does anyone have a source for carbon or graphite tubes to replace the ones that hold the sponsons on.
Oh yea, does anyone have a source for carbon or graphite tubes to replace the ones that hold the sponsons on.
11-20-2007, 09:17 PM
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11-20-2007, 10:16 PM
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RE: OS .21 vz-m won't rev
eclozon, what Fail Safe are you using ??
I'm using a Ofna and never have to reset it, even after removing the battery pack to recharge the battery pack.
Seems to work fine.
http://www3.towerhobbies.com/cgi-bin...&I=LXEYG2&P=ML
I'm using a Ofna and never have to reset it, even after removing the battery pack to recharge the battery pack.
Seems to work fine.
http://www3.towerhobbies.com/cgi-bin...&I=LXEYG2&P=ML
11-20-2007, 11:35 PM
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RE: OS .21 vz-m won't rev
I have read on a thread somewhere here that adding an external Failsafe create a conflict with the built in Failsafe (maybe in PPM only or is it HRS??).
according to the manual antenna should be outside, and the maximum operating range is 80meters (optimum condition).
Power requirement for the transmitter NiCd or NiMh @ 9.6v or 12v dry cell,
Power requirement for the receiver is 6v NiCd or NiMh ONLY, no dry cell.
Dan.
according to the manual antenna should be outside, and the maximum operating range is 80meters (optimum condition).
Power requirement for the transmitter NiCd or NiMh @ 9.6v or 12v dry cell,
Power requirement for the receiver is 6v NiCd or NiMh ONLY, no dry cell.
Dan.
02-26-2008, 04:40 PM
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RE: OS .21 vz-m won't rev
I hav recently purchased a pre-assembled Dumas Hawk .21 outrigger. It came with no setup instructions at all. Is there anyone that can help me, perhaps a site that would explain the process of setup and adjustment.?
02-26-2008, 04:55 PM
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RE: OS .21 vz-m won't rev
This may help a little.
http://home.earthlink.net/~jpreusse/hawk/
If not explain any problems you are having. The Guys on this site are GREAT !
Ralph
http://home.earthlink.net/~jpreusse/hawk/
If not explain any problems you are having. The Guys on this site are GREAT !
Ralph