7.5 outboard rigger
- Thread starter damien_au
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_laxmasta2039
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- Oct 15, 2002
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the only ones i know of are Mad Dog racing's one and the Prather Spitfire- are you thinking of getting one of these?
check out "OB hydro pics", that's my 3.5cc Pheonix OB rigger, being broken in and running on 25% fuel, probably around if not more than 40 mph already.
Joe
check out "OB hydro pics", that's my 3.5cc Pheonix OB rigger, being broken in and running on 25% fuel, probably around if not more than 40 mph already.
Joe
_laxmasta2039
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- Joined
- Oct 15, 2002
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- 817
yea,
the links on the home page [of intlwaters]
it's under commercial i think.
what engine are you using?
Joe
the links on the home page [of intlwaters]
it's under commercial i think.
what engine are you using?
Joe
Hi Damien,
Does your box have the model number on it? 8701 or 8702
Does it have an oiling hole in the top of the leg or where the top crank ballrace is?
I also have a 7.5cc outrigger hull (Prather Spitfire II) that i should do something about putting together to run for something different.
GT
Does your box have the model number on it? 8701 or 8702
Does it have an oiling hole in the top of the leg or where the top crank ballrace is?
I also have a 7.5cc outrigger hull (Prather Spitfire II) that i should do something about putting together to run for something different.
GT
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GTR,
I just sold my Prather spitfire 7.5. ****, it was fast. My advice, add a 1 to 1 1/2 inch spacer between the mount and the transom. Really makes a difference in spped and ride attitude. Three blade X-447 or 450 cut back and thined.
Sold it because as it stalled out in the lake the ass end with the engine being on the back was so heavy it would go under water only leaving the tips of the sponsons showing. Very hard to retrieve w/no retrieve boat! Not all of us have our personnal retrieve boat! LOL ;D
I just sold my Prather spitfire 7.5. ****, it was fast. My advice, add a 1 to 1 1/2 inch spacer between the mount and the transom. Really makes a difference in spped and ride attitude. Three blade X-447 or 450 cut back and thined.
Sold it because as it stalled out in the lake the ass end with the engine being on the back was so heavy it would go under water only leaving the tips of the sponsons showing. Very hard to retrieve w/no retrieve boat! Not all of us have our personnal retrieve boat! LOL ;D
Hi Damien,
You'd probably want an X450 prop if you going to run a 2 blade or a Prather 235. As a rule of thumb 3 bladers load up the engine more - like to run very surface piercing - and you would usually go down 1 size from a 2 blader.
What nitro are you planning on running?
8701 & 8702 are subtley different - 8702 flywheel held on by an allen bolt and usually lightened. 8702 uses long reach plugs - has a machined water jacket on top of a 6mm thick head button. Thats mostly it. You can drill an oiling hole for the lower end in the mounting plate below the PTO - I do this to all my OBs. You cannot do the oiling hole behind the from bearing. Don't worry about it just make sure you clean the motor at the end of the day and run some after-run oil through it. I like ATF myself - it seems to do a good job.
Enough waffle for now.
GT 8)
You'd probably want an X450 prop if you going to run a 2 blade or a Prather 235. As a rule of thumb 3 bladers load up the engine more - like to run very surface piercing - and you would usually go down 1 size from a 2 blader.
What nitro are you planning on running?
8701 & 8702 are subtley different - 8702 flywheel held on by an allen bolt and usually lightened. 8702 uses long reach plugs - has a machined water jacket on top of a 6mm thick head button. Thats mostly it. You can drill an oiling hole for the lower end in the mounting plate below the PTO - I do this to all my OBs. You cannot do the oiling hole behind the from bearing. Don't worry about it just make sure you clean the motor at the end of the day and run some after-run oil through it. I like ATF myself - it seems to do a good job.
Enough waffle for now.
GT 8)
Hi Damien,
If yours uses the long reach plugs great - they are much better than the short reach ones.
Why such high nitro - I'd suggest 40-50% no more. If you haven't run a lot of boats you could start out with 25% and work up. You will have oil mixing issues at the % you are talking about.
I will post the difference in weight between the 2 flywheels for you tonight. (have both) Your carb size will limit the amount of power you can get from it and if you really want to chase power go for a J pipe before trying to tip in that much Nitro.
GT
If yours uses the long reach plugs great - they are much better than the short reach ones.
Why such high nitro - I'd suggest 40-50% no more. If you haven't run a lot of boats you could start out with 25% and work up. You will have oil mixing issues at the % you are talking about.
I will post the difference in weight between the 2 flywheels for you tonight. (have both) Your carb size will limit the amount of power you can get from it and if you really want to chase power go for a J pipe before trying to tip in that much Nitro.
GT
Here are some pics of my rigger.
Just ran it for the first time, with a X445 2 blade, waiting for a 3 blade X447!
Sat the outboard as high as I could with the octura mount and tilted it down as far as possible.
The torque of the engine would lift the front left sponson a good 3-4 inches out of the water!!! and the tip of the turn fin on the right (facing from the rear of the boat) would just be in the water!
It is verry unpredictable as when you get on the throttle it would lift rather quickly.
The god news is that I only fliped it once! (paid a young kid 5 bucks to swim out and retreive it!!)
I also learned the value of a hopper tank, should be able to run an enduro with a 8oz & 4 oz hopper!
Any tips on how to improve on this un predictable thing ???
Just ran it for the first time, with a X445 2 blade, waiting for a 3 blade X447!
Sat the outboard as high as I could with the octura mount and tilted it down as far as possible.
The torque of the engine would lift the front left sponson a good 3-4 inches out of the water!!! and the tip of the turn fin on the right (facing from the rear of the boat) would just be in the water!
It is verry unpredictable as when you get on the throttle it would lift rather quickly.
The god news is that I only fliped it once! (paid a young kid 5 bucks to swim out and retreive it!!)
I also learned the value of a hopper tank, should be able to run an enduro with a 8oz & 4 oz hopper!
Any tips on how to improve on this un predictable thing ???
