need more power for mc28

thanks in advance

phil


Last edited by PhiLLaY on Sat Jan 20, 2007 6:10 am; edited 1 time in total

The '28 is by far the hardest NSR to get power from;

The exhausts have restrictors in the headers (and weigh a ton), either replace the chambers (Tyga are good and cheap) or take the pipes off and spend some time with a dremel removing them.

Like all NSR's the airbox is restrictive, 4*1" holes in the lid seems to works best.

The ignition is retarded, a vaguely effective workaround is to use the flywheel from an MC21 but you're not going to get really good power (anything over 60bhp) out of a '28 on the standard card, the HRC card is the way forward.

As with all mods, check the jetting
_________________
Please do not PM me technical questions, if you can't find it on the Forum start a thread

thanks for the reply, im not after world record breaking power but something to give me a bit more G's from 0-140km.

Would i feel anything if i changed the end cans, drill some holes in the airbox?
_________________
Stock and really slow MC28SE Repsol Rep... =(

Cans do very little, removing the restriction in the pipes has to be done and is worth plenty of ponies. See here for the difference race pipes alone make to an MC28.
The airbox is a restriction but the '28 has far bigger problems, mainly the pipes and ignition.

Tyga did a bit of a '28 on a std card here
_________________
Please do not PM me technical questions, if you can't find it on the Forum start a thread

While not an MC28 here is some graphs of an MC18.

Purple trace is stock pipes and cans

Blue trace is stock pipes with swarbrick cans

A small increase all the way up, maybe not really worth it but every increase is a step forwards.


_________________
If I have to take the carbs off once more...

so it looks like i gotta take off the pipe and start the dremel. If i take the pipes off would the gaskets need to be replaced. Should i clean out the cans before buying new cans its probably filled with crap
_________________
Stock and really slow MC28SE Repsol Rep... =(

MC28 cans are more restrictive than the earlier models too. For a cheap fix, slip on some MC21 cans... they aren't the perfect answer, but they are both lighter and less restrictive.

Better still, buy some MFactoryWest cans from the Marketplace!
_________________
Andy.
NSR-WORLD.COM

Please keep all responses to Forum posts on the Forum so that others may benefit.

Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.

Check us out on Facebook! Please "like" our page!

Andy wrote:MC28 cans are more restrictive than the earlier models too. For a cheap fix, slip on some MC21 cans... they aren't the perfect answer, but they are both lighter and less restrictive.

Better still, buy some MFactoryWest cans from the Marketplace!

Are those cans a direct bolt-on to stock chambers?
_________________
james
Its not how fast you go...Its how you go fast.
MC21 Rothmans
RS250
RC31
CRF250X
748R
Porsche (many)
http://members.rennlist.com/j911brick/rennlist3_002.htm

hi guys,

jetting my bike... any competent bike mech with a dyno can perform this?
_________________
Stock and really slow MC28SE Repsol Rep... =(

Probably not
_________________
Please do not PM me technical questions, if you can't find it on the Forum start a thread

We cant even find one in the UK lol
_________________
If I have to take the carbs off once more...

j911brick wrote:
Are those cans a direct bolt-on to stock chambers?

The bolt pattern is the same, but on some pipes (MC28 for example) the "stub" needs to be cut back flush with the flange to allow the cans to pull up nice and snug.
_________________
Andy.
NSR-WORLD.COM

Please keep all responses to Forum posts on the Forum so that others may benefit.

Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.

Check us out on Facebook! Please "like" our page!