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Discussion Starter · #1 ·
I am interested in altering the ignition curves and rev limit in a carburated R6. Does anyone flash or otherwise alter these ignition boxes? I am interested in running methanol in one of these engines and re-jetting and tuning the ignition curves as required. The box seems to be made by mitsubishi and the numbers are the box are as follows:

F8T362
71 5EB-30 9212
Exterior >PBT<
Interior >PUR<

Can someone help? Thanks!
 

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You don't want to raise the rev limit unless you are planning on rebuilding at least the top-end of the motor to take the added strain. 15k not high enough?

I would look into stroking the motor and keeping the stock rev limit.
 

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I'm assuming your going to do so for drag racing. Methanol is an awesome fuel to make some impressive HP #'s from.

A little more info for what your going to or plan on running it for will help. But I would start with doing some porting, either shaving the head or using a smaller gasket, running some fairly long duration cam set-ups, and most likely running a little hotter plug (but you'll wanna trial and error til you work with hotter plugs..

Base line, you'll wanna start basically doubling the amount of fuel. Double main jets, raise the needle, open fuel screws. Can be a big pain in the ass dialing in jetting, but it is very important with methanol.

And if you have experience with methanol, you know you should basically run the whole fuel system dry of the fuel when not running or used....it LOVES to eat aluminum and especially fuel lines.

Also know that if you are running temperatures below 60 degrees or so is going to require alternate fuel for getting the engine started easily.

Also, start with timing curve stock, get jetting figured out, then you will know how rich or lean you are in places and how much room you have, then you can start playing with timing.......which advancing with methanol will give signifcant gains.
 

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Discussion Starter · #5 ·
The application is circle track mini sprints. Already have the engines running on methanol no problem. I am just interested in how to now fine tune them by flashing or programming the ignition box. Thank you all very much for the replies and for the mechanical advice. What I'm trying to ask is solely electronic. Is there a hack or programming method for these black boxes?
 

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Ah yes, never think about the mini-sprint side of these engines. YOu know what i mean about drag racing, the application in mini-sprint is very similar, just not quite the duration of cam etc...


If you're running methanol already and you have jetting figured out, you're in good shape. If you haven't, you need to have it dynoed (at crank) to find hp/trq curve.

Have you tried any aftermarket ignition advance rotors? That could be a possibility that would be worth a try.


Otherwise, contact yamaha directly to ask about reprogramming.



what all engine mods have you done, and what all are you allowed to do?

Not clear on your rules/regs for mini-sprint.
 

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ProfessorSpeed said:
I didnt say raise the rev limit, did I? Thanks for the reply, but for this class, displacement is strictly controlled.
Sorry about that. Why would you want to lower the rev limit, never heard of anyone wanting to do that before.
 

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he's not wanting to lower the rev limit. he's just looking for reprogramming the ignition cdi. something that is more effective and useful for their mini-sprints.

this is done alot for drag racing and the like..
 

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Re: Altering the ignition curves and rev limit in carburated

ProfessorSpeed said:
I am interested in altering the ignition curves and rev limit in a carburated R6.
Sorry I was looking at this...
 

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Out of curiosity Professor, where are you from? There is a guy in southern Illinois that works on motors for the modifieds. My dad had a cbr600f2 motor on his a few years back. He was running hilborne F/I on his. He had Bonner,the guy in Ill, recam, port/polish the heads, stainless valves, etc. He also took gears 4-6 out since he didn't need them on the 8th mile tracks he ran. I can get you the number if interested. What chassis do you run?
 
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