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Old 12-30-2008, 10:40 AM   #1
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Default Pullstart/Shaft Start/Bump Box? - Ofna Hyper 7

I just bought a Hyper 7 PBS, which comes with a pullstart on the mac .28 engine. This is my first nitro car (been running electric and 1/5th scale gas, and nitro airplanes), but I know enough to know that pullstarts are lame.

Is there any use in converting this thing to a shaft start, or is the bump box the way to go? Ofna has about 15 different boxes and I have no idea which to get, or if I should just get another brand. I would like to run the box off a single 12v battery, since I have one on hand.

Thanks!
Dominic
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Old 12-30-2008, 10:46 AM   #2
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One more (dumb) question - if I were to get a bump box, could I use it right off with the pullstart still on the motor, or would I have to change it out for something else? My guess is that since the bump box engages the flywheel, the pull start wouldn't matter.
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Old 12-30-2008, 08:53 PM   #3
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Hey mate a starter box is definitely the way to go I have got a hpi hellfire and a mugen mbx5r buggy and they both fit on the big black hyper starter box. The hyper starter box takes a 12 volt battery so it is nice and powerful. You dont need to listen to me rabble on, but hey each to their own.


Hope i have helped you

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Old 12-30-2008, 08:54 PM   #4
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And the pull start shouldn't effect using a starter box. I would suggest getting a back plate instead of the pull start though.


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Old 12-30-2008, 10:13 PM   #5
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alright
im going to guess that it is a dynamite mach. i am going to suggest that you go with bump box, i suggest the ofna truggy starter box...
your going to want to get a plate for the back of the motor... you can keep that pull on it, but they rob horsepower... lol just go to amainhobbies.com and you will be able to find everything there for it you need?????
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Old 12-30-2008, 10:17 PM   #6
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ofna bump box+lipo&never look back..whatever it takes, you get them youll be set. just be patient to get the right stuff so you dont run into other issues choosing gear
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Old 12-31-2008, 04:09 AM   #7
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Default Da Bump

On the cheep? Get the OFNA black box last two #'s 45 and run your 12 volt. Will work with bugs and truggs plus some 10th scale. Had mine three years and works every time. You don't have to change the back plate 'till your looking for more power. But you need to get in there and clean things if you want the motor to last so change it then.
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Old 03-09-2009, 01:47 PM   #8
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umm yes it actually does matter if you have a pullstart on the engine. It has a one way bearing on it and if the bump box spins the opposite way, the engine rotation will pull the pullstart cord in and it won't work. So make sure the bumstart rotates the right way...
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Old 03-09-2009, 07:16 PM   #9
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Quote:
Originally Posted by screamin' eagle View Post
I just bought a Hyper 7 PBS, which comes with a pullstart on the mac .28 engine. This is my first nitro car (been running electric and 1/5th scale gas, and nitro airplanes), but I know enough to know that pullstarts are lame.

Is there any use in converting this thing to a shaft start, or is the bump box the way to go? Ofna has about 15 different boxes and I have no idea which to get, or if I should just get another brand. I would like to run the box off a single 12v battery, since I have one on hand.

Thanks!
Dominic
Dont go shaft start. The pull start is fine for now in my opinion. I made the mistake of putting on a shaft start and nothing but problems. As Jaz would say the shaft start is way to powerful for the engine.

The shaft start puts way to much lubrication on the internal parts and slips when trying to start. I always had to pull apart the back plate and clean the shaft so that it would grab. It will also wear out the one way bearing.

Once I put the pullstart on it now starts with one pull. Obviously the starter box is the way to go but if you want to save some cash for now use the pull start until it breaks.
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Old 03-09-2009, 08:59 PM   #10
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You may have to grind the crank with a dremel if you put in a backing plate.

I wouldn't use bump box with pull start because it will have extra mass rotating anyway, so if its there just use it, otherwise convert it the right way
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Old 03-10-2009, 11:32 AM   #11
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I should update the thread -

I went with a regular backplate (no grinding necessary, direct fit). I sealed it with blue RTV gasket maker and got an Ofna bump box, which I am running off 2 6 cell nimh packs. Works great, no more air leaks, no more problems for the past month or so.

Thanks for all the input.

Dominic
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Old 03-10-2009, 03:21 PM   #12
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Thumbs up bum box forever

hey man, i just wanted to let u know that if i were u i would convert all my nitro's to bump box, i currently have a rc10gt with a os max .12 cv motor and a ofna ultra mbx with a axial .28RR motor and both are bump box, the reason i say bump box is because it lightens up the car a little bit and plus it is less expensive because pull starts break and roto starts just add weight. so whether it be for bashin or racing i say go with bump box. less weight and less money loss
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