GN250 Cafe Racer

[ducatilover]

As long as it's a cool looking GN

[highace10]

and that it is...a cool looking GN. Especially when its done..

[ducatilover]

Yours should look sweet

[JMSR]

That's fantastic work highace10! Brilliant job on the frame.

Is it my imagination or have you lowered the trailing arm past the clash point on the right side pillion peg bracket? I'm interested in hearing how others have tackled this before I go cutting the clash point out and welding in a new section between the peg and exhaust mount.

The wheels look great. I've just started reconditioning a set of wire wheels and am busting to fit them. Weeks away yet though.

As for the power, don't worry there is a small spark to the GN. I've been chatting to a couple of guys from the US and China. Both from serious engine tuning companies (1 holds/held the record for 125cc 2 stroke 1/4 mile at 10.6s!!!). They both pan the GN, pointing out the dismal max valve lift causing a bottleneck for gases making it a poor choice for competition tuning. BUT they have both played with them and succeeded in going over 30hp at the back wheel and confidently talk of a reliable long life motor putting out between 25-28hp in the upper half of the rev range (stock is between 12-16hp in the middle. Manual says 20-22hp but that's at the fly wheel and probably typically optimistic) without too much effort. That sort of hp on a lightened GN would equal a lot of fun for street bike, sure, not competition grade fun, but fun non the less.

[highace10]

I ended up just cutting the bracket off and rewelding what was required to mount the exhaust? If you're interested in can post a pic of what I did. The issue I'm having now is that the swing arm is probably too far with that length shock. The chain has very little clearance from the swing arm, prob about 5mm with no weight on the bike. With me sitting on it, it improves a bit. I'm going to try and find a shorter set of shocks (maybe 14inch) and give the chain some clearance. Other than that I don't see any more problems....touch wood.

I now have my tank and seat painted and all the parts needed to finish this bloody thing. All elctricals have been relocated to under the pod on the rear section and my K&N oval pod filter will be going in very soon. I'll then get round to sorting out the front suspension...that should be fun.

This Thursday I will hopefully great some life into it and finally hear it for the first time time in 3 months. Maybe a ride of everything goes well.

Gonna need some luck though

An upspec GN engine would be nice! Maybe something to think about later on down the track.

[JMSR]

I'd like to cut my peg brackets off but I'd have to have a yarn with local the garages to see if they'd pass it without a frame mod cert or even see if they consider my modded seat single or double.

Keep me informed of your progress with the pod filter. I'd like to do the same and it would be great if somebody walked out into the minefield first. Still I've heard a good few people argue in favor with good gain so there must be a trick or two.

[ducatilover]

Yup the GN does need more lift, but I'm not certain about putting more stress on the standard valve springs (they're pathetic) or the rockers. The biggest restriction that's easy to fix is the exhaust ports, they're not matched, they're disgusting.

If you make any frame mods look factory you may get away with it

[JMSR]

Yep, after market springs will be a must. Web Cam Racing Cams do 2 stages of cam and valve spring kits for the DR250 (82-85) but I've been snooping elsewhere. I'm getting my cam from the Devil himself! Only cost me my soul so far but I figure the GN is worth it. Can't say anymore until it's paid for and ordered though. Talk is cheap as they say.

I have to get that back end up at some stage so the pegs may come off yet. Just have check a few things out first. Don't tempt like that though, every night I talk myself out getting the cutting disc out.

Has anyone looked into the wiring of a rear rim onto a front hub (disc) to have a fatty front tyre like this guy http://www.youtube.com/watch?v=jXfcXSiI9cQ ? I'm more than a little interested in doing this myself.

[ducatilover]

I'm going to be lacing a new front rim on mine.
I've been considering getting two 17 inch rears from a DR and doing it so I have the ability to have pretty tyres!

The 18 front is way over the top really.
I've also been thinking of throwing on my spare set of ZXR400 forks

[JMSR]

2 17s would make a sweet looker for sure!

Interesting bout the forks. It's a long term mod for me but on the list for sure. It's starting to sound like there are some good options.

[ducatilover]

I'd love to get the forks/brakes off an old GS twin and mount them on my wires, it'd be rather neat!

[highace10]

Well... Now the problems start. Bloody oil filter cover cracked and pissed oil all over the driveway. Another is on order. The bike idles fine but on application of throttle she hesitates a bit. Jets will hopefully help riven her up a bit.

I've also just order some new main jets so they hopefully won't take too long to get to me. Received word from another bloke that he shimmed his suspension 1-1/4 inches and redid the fork oil, works a treat. I'll have to try it.

[JMSR]

Sorry to hear about the cover. At least it's an easy fix thanks to it being the bike it is. What did the bloke use as the shim?

[ducatilover]

Well... Now the problems start. Bloody oil filter cover cracked and pissed oil all over the driveway. Another is on order. The bike idles fine but on application of throttle she hesitates a bit. Jets will hopefully help riven her up a bit.

I've also just order some new main jets so they hopefully won't take too long to get to me. Received word from another bloke that he shimmed his suspension 1-1/4 inches and redid the fork oil, works a treat. I'll have to try it.

Sucks about the cover, I could have sent you one for the cost of shipping

My '04 GN was binding the front springs with that much spacer
I've been meaning to design a preload adjuster for mine, I reckon it'd be a cool feature and good for a giggle.
Have to find somebody to let me use their lathe lol

[highace10]

I found a new cover from a wrecker in Western Australia. $20 to my door. The bloke used washers. He was nice enough to drop some off in my letter box about an hour ago.

I'll try an inch first and see how it is.



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