NC30 Mods
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- Settled in member
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- Joined: Tue Mar 24, 2009 6:18 pm
- Bike owned: NC30
- Location: Durham, UK
Re: NC30 Mods
Hello All,
Main reason for using a Version 3 Megasquirt standard board is first, I already had it, and second, the standard board is easy to modify, Microsquirt will be extremely difficult to do any mods to. There is loads of room in the tail of an NC30, so there is no issue of finding a place to fit it. A V3 MS I think is cheaper than a Microsquirt.
How much time does an NC30 engine spend below 3000 rpm? I don't think the software will do semi-sequential
injection on an NC30 engine, because the injection intervals are not evenly spaced. The software will do semi-
sequential on an inline 4. I needed to build a small circuit to drive the CBR600 tacho from the ECU and I have the
ignition drivers on the main heatsink, these are the most likely components to fail, so I made them easy to change if necessary.
Just ask if I haven't answered anything.
Dave.
Main reason for using a Version 3 Megasquirt standard board is first, I already had it, and second, the standard board is easy to modify, Microsquirt will be extremely difficult to do any mods to. There is loads of room in the tail of an NC30, so there is no issue of finding a place to fit it. A V3 MS I think is cheaper than a Microsquirt.
How much time does an NC30 engine spend below 3000 rpm? I don't think the software will do semi-sequential
injection on an NC30 engine, because the injection intervals are not evenly spaced. The software will do semi-
sequential on an inline 4. I needed to build a small circuit to drive the CBR600 tacho from the ECU and I have the
ignition drivers on the main heatsink, these are the most likely components to fail, so I made them easy to change if necessary.
Just ask if I haven't answered anything.
Dave.
- Cammo
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- Bike owned: NC30
- Location: Melbourne, Australia
Re: NC30 Mods
whizzo944 wrote:I just posted 2 new photos here
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Nice work, those throttle bodies look fantastic!
"It's just a ride" Bill Hicks
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Re: NC30 Mods
I've got another question!
Sorry
I've noticed on your throttle body's that it looks like the taper starts much earlier than the standard carbs, for the bell mouths, is this something you've calculated or is it a guess on what would work well with fuel injection? As you have in theory at least reduced the length of the inlet port.
Thanks for some great info Dave

Sorry
I've noticed on your throttle body's that it looks like the taper starts much earlier than the standard carbs, for the bell mouths, is this something you've calculated or is it a guess on what would work well with fuel injection? As you have in theory at least reduced the length of the inlet port.
Thanks for some great info Dave

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- Bike owned: NC30
- Location: Durham, UK
Re: NC30 Mods
Hello,
The taper is a total guess, we ( my friend who actually made the TB's for me) just drew them and decided that the taper "looked about right". I don't know if the inlet tract is shorter, it may be a little bit, but at least it's
straight now
Just keep asking questions, it's no problem.
Dave.
The taper is a total guess, we ( my friend who actually made the TB's for me) just drew them and decided that the taper "looked about right". I don't know if the inlet tract is shorter, it may be a little bit, but at least it's
straight now

Just keep asking questions, it's no problem.
Dave.
Re: NC30 Mods
Hi Dave.
Im new to the site and live in New Zealand.I have a race NC30 that I am resurecting.I raced it for years in the UK and did a lot of development on the engine with RLR motorsport.We always talked about fuel injection but never did it.You article is interesting and I was wondering if you got the fuel injection running succesfully and did you get any gains over the carbs.
Do you have a drawing for the Throttle bodies you might be pursuaded to part with.
Thanks Gary
Im new to the site and live in New Zealand.I have a race NC30 that I am resurecting.I raced it for years in the UK and did a lot of development on the engine with RLR motorsport.We always talked about fuel injection but never did it.You article is interesting and I was wondering if you got the fuel injection running succesfully and did you get any gains over the carbs.
Do you have a drawing for the Throttle bodies you might be pursuaded to part with.
Thanks Gary
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- Settled in member
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- Bike owned: NC30
- Location: Durham, UK
Re: NC30 Mods
Hello Gary,
My friend with the engineering company drew the TB's on AlphaCAM. I don't know if he still has the drawings and what format they are in, but if he has, I don't see a problem letting you have a copy. There were 3
machining op's to make them, lathe and then 2 milling op's Only bit of tooling I needed to buy was a reamer for the throttle shafts, they are 5/16 in. !!!!! On a Jap motorcycle !!!! They started life as a round 90mm billet of HE30,
or similar. The project has unfortunately stalled a bit at the moment, mainly because I'm bone idle !!!!! I will get it running soon though, just don't know how long soon is.
Dave.
My friend with the engineering company drew the TB's on AlphaCAM. I don't know if he still has the drawings and what format they are in, but if he has, I don't see a problem letting you have a copy. There were 3
machining op's to make them, lathe and then 2 milling op's Only bit of tooling I needed to buy was a reamer for the throttle shafts, they are 5/16 in. !!!!! On a Jap motorcycle !!!! They started life as a round 90mm billet of HE30,
or similar. The project has unfortunately stalled a bit at the moment, mainly because I'm bone idle !!!!! I will get it running soon though, just don't know how long soon is.
Dave.
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- Bike owned: NC23, NC30
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Re: NC30 Mods
I'm trying to do EFI on my NC30 and came across this thread. Fitting the throttle bodies is the big challenge for me, too. Does anyone know if this bike ever ran?
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Re: NC30 Mods
Hello,
Yes, this bike has run on several occasions with a Megasquirt MS2 ecu. I have just ordered a different ecu
from Ignitech because Megasquirt 2 won't do fully sequential injection. I originally used injectors from a Honda
CBR600FS but they were too big, I am now using the primary injectors from a 2005 CBR1000RR. This bike is undergoing
major modification, ZXR400 forks and brakes, Tyga bodywork, VFR750 rear wheel and rear cylinders exhaust through
the seat, if I ever get it finished.
Dave.
Yes, this bike has run on several occasions with a Megasquirt MS2 ecu. I have just ordered a different ecu
from Ignitech because Megasquirt 2 won't do fully sequential injection. I originally used injectors from a Honda
CBR600FS but they were too big, I am now using the primary injectors from a 2005 CBR1000RR. This bike is undergoing
major modification, ZXR400 forks and brakes, Tyga bodywork, VFR750 rear wheel and rear cylinders exhaust through
the seat, if I ever get it finished.
Dave.
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- Settled in member
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- Joined: Sun Aug 12, 2012 10:51 pm
- Bike owned: NC23, NC30
- Location: The Island of Hawaii
Re: NC30 Mods
Cool. I sure hope my project won' take 4 years, that takes some serious persistence!
I'm going to try to use throttle bodies from the GPZ1100 (34mm) with a different of injectors. The trickiest thing is clearly going to be getting the TBs mounted properly to the airbox...
I saw you replaced the trigger wheel. Did you run into problems with the stock 8-1 pattern or did you just want to upgrade?

I'm going to try to use throttle bodies from the GPZ1100 (34mm) with a different of injectors. The trickiest thing is clearly going to be getting the TBs mounted properly to the airbox...
I saw you replaced the trigger wheel. Did you run into problems with the stock 8-1 pattern or did you just want to upgrade?
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- Settled in member
- Posts: 37
- Joined: Tue Mar 24, 2009 6:18 pm
- Bike owned: NC30
- Location: Durham, UK
Re: NC30 Mods
Hello,
I changed the trigger wheel because Megasquirt works well with a 36 - 1 wheel. The original wheel is just a thin
steel pressing around the starter clutch, I cut that off and press fitted the new wheel. You have to make the new wheel
similar to the original because it retains the rollers in the starter clutch
Any more questions, just ask :-)
Dave.
I changed the trigger wheel because Megasquirt works well with a 36 - 1 wheel. The original wheel is just a thin
steel pressing around the starter clutch, I cut that off and press fitted the new wheel. You have to make the new wheel
similar to the original because it retains the rollers in the starter clutch
Any more questions, just ask :-)
Dave.