28SE derestriction questions

Hi everyone, I'm a soon to be NSR 28SE owner from New Zealand (in transit from Japan)

My plan is for Tyga Pipes and mod the airbox, thats the easy bit. I'm thinking of using a offset key for the flywheel to advance it instead of buying a HRC 030 card. Anyone got advise on the key and how much advance to use. Where I live we only have 95 octane gas and 98 with 10% bio alcohol coming soon.

Will there be any major power gains with the card over just advancing the ignition.

Do I need a HRC jet kit or will I get away with just changing main jets and leaving the pilot-needle alone. If I just get main jets what range of sizes should I get.

Thanks in advance for the help:)

Hi Mate

Good questions!

I have just returned from Japan where i bought a 21 and a 28. Will sell one and keep the other. Swinging towards keeping the 28 at this stage.

Look forward to the replies.

Cheers

Mark

MC21 with virtually no modification will see 60+hp easily, you'll be lucky to get very far into the 50's on the MC28 without the HRC bits. The '21 makes 45hp stock but was designed to make 60+; the '28 was deliberately restricted to 40hp, and Honda deliberately made it difficult and expensive to de-restrict.

If you want a smooth tractable bike that looks pretty and will get out-run by the local farmer on his chicken chaser, keep the MC28. If you want it to make any kind of reasonable power you will need the card, pipes, jet kit/needles, and modified airbox at least, and even then the MC21 will still be better!
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Andy.
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Here here Andy.

Yonks ago I advanced a 28 about 5 degrees without HRC card. It made 66hp on the brake with a few (lots) of bolt on bits, but struggled down low with over advanced timing.

My advice would also be to keep the 21.

Nothing on a std '28 is geared towards decent top end power or speed;

Pipes are restricted, Dremel and patience or race pipes.
PGMIV is retarded, '21 flywheel or HRC card.
Barrels are ported too low, port them or fit 21 barrels, very little difference really but it is there.
Carbs are annoying to work on, 21 carbs or live with it.
It's only geared for 115mph, change it or live with it.

My '28 roadbike has the std pipes opened up, std card, an entire '21 engine including carbs fitted and is as quick on the road in real life as any other 250/400 grey import bike from the same time.

On the plus side the engine does swing up into place on the '28 if you get the rear mount bolt in first making swapping motors a doddle and it's as trick as a trick thing doing a card trick
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Fontyyy....what are you on about? Haven't you sobered up yet?

Look, these wafflers will go on for ever about this and that... What they're really trying to say, is the simplest way to fully de-restrict a 28 is to buy a 21! Simple!
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NSR300R - Why did i ever have a 250...

Matt@TYGA wrote:Fontyyy....what are you on about? Haven't you sobered up yet?

Mr Andy told me you can't put an engine in a '21 by just bolting the lower rear mount in place then swinging the engine up into place, on a '28 you can, as it's not got the little noggins underneath the front mounts.

And I was quite sober anyway
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I know a 21 would have been easier and faster than the 28, but I wanted a 28. I just want it to go as good as it can with a few mods.

How much more advance does the 21 flywheel have compared to the 28. Is there much gain to be had from the HRC 030 card over a 21 flywheel/advanced 28 flywheel. I'll probably get a 030 card at a later date once my funds have recovered.

Could have been worse, I was thinking of getting a Aprilia for awhile.

Have fun with the 28 it's a much nicer bike in more than one way.

I always laugh when these guys bag on the 28 because it makes 5 less hp or is harder to make hp. Jeesh, just out ride whoever you're riding with and 5-10-15-20hp isn't going to make a difference.

If you need hp that bad buy a Busa!

Spoken like a true MC28 owner!

Fine if you can ride round the guy with the MC21 with 10~20hp more, but what if he can use it too? Buggered if I'd want to ride anything with less than 65hp now, and I know someone who wouldn't even swing a leg over anything less than 70hp these days unless he was being paid!!


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Andy.
NSR-WORLD.COM

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MC28 owner.

Hey I love them both and could have owned a 21 many times over and for far less money too. It's a personal preference thing really and any NSR in the States is rare.

When I finally get around to rebuilding my engine.... sure I'd love to hear some tricks from you guys to gain a hp or two but it's not a priority for this bike. If I was going to be racing it, damn straight every bit counts, but for the canyons no problem just having fun.

apexxn wrote:
...but for the canyons no problem just having fun.

And I'm not jealous at all! Some fantastic roads you have there!
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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.

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Ouch, nithing but '28 haters I thinks me little 28 makes 65HP. What do you think Matt? I've got those farmers in my sights
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1995 A kit TZ 250
1994 Rothmans NSR 300sp SOLD
1998 RM 250 freestyle/motorcross
1998 Meathanol burning CR 500 AF super retard/motorcross/sand dunes/play bike

I've tested plenty of NSR300's that have made less than 65hp so dont count your chicken yet
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If I have to take the carbs off once more...