Boo hoooooooooo - Betty has BANGED!

**MSTRS:Me** · 14th June 2005, 09:53

Originally Posted by Paul in NZ

also... Correct me if I'm wrong but an XR 250 has dual carbs????? Is the head casting the same as CSL's??

Mid 80's only. One of the 'Seemed like a good idea at the time' sort. Don't touch.

**XTC** · 14th June 2005, 10:54

XR250A motor is the same though I think the gearbox ratio's differ. It will be cheaper to rebuild the existing motor as ther are still plenty of parts out there. Any way it's hard to tell what's needed till she's stripped. The bike that is - not CSL....

**Ixion** · 14th June 2005, 11:21

Originally Posted by XTC

XR250A motor is the same though I think the gearbox ratio's differ. It will be cheaper to rebuild the existing motor as ther are still plenty of parts out there. Any way it's hard to tell what's needed till she's stripped. The bike that is - not CSL....

I suspect the cam profiles might be different too.(Don't know for sure though so if someone who does says I'm wrong, believe them) That was usually what they did in that era, shove a trailie engine into a road frame, and change the gearing, cam profiles (more high rev power less bottom end) , and tweak the carbs and exhaust to suit. Maybe a higher comp ratio, though the trailies were usually pretty high to start with.

Exactly the same on the Yamahas (SRX250, XT250, TT250). Suzuki and Kawasaki both did the same also, though I can't remember the model numbers.

**ManDownUnder** · 14th June 2005, 11:39

Originally Posted by Ixion

And would Ms Celtic Sea Lily want to cope with kickstarting a 500 single ?

If I can paraphrase that to make it accurate...

more like the 500 would start kicking CSL (in the ankle...)

.... ouchies!

**Motu** · 14th June 2005, 11:45

Originally Posted by Ixion

I suspect the cam profiles might be different too.(Don't know for sure though so if someone who does says I'm wrong, believe them) That was usually what they did in that era, shove a trailie engine into a road frame, and change the gearing, cam profiles (more high rev power less bottom end) , and tweak the carbs and exhaust to suit. Maybe a higher comp ratio, though the trailies were usually pretty high to start with.

Exactly the same on the Yamahas (SRX250, XT250, TT250). Suzuki and Kawasaki both did the same also, though I can't remember the model numbers.

I think you are right,from memory the CB250RS seemed happier to rev than the XR250,the XR was a bit asthmatic in the top end.The gearbox seemed closer ratio too.But I forgot what colour the socks I put on this morning are....(I could look,but I'm trying to improve my memory see...)

**Paul in NZ** · 14th June 2005, 11:48

Yes but is a GB engine the same (mounting wise) as an XR engine?

My theory is that GB400 motors will not be hard to find as everyone wants the 500... and some folk will want to put XR600/650 engines in to GB's anyway..

But a GB400 would provide a significant upgrade to a 250 and give electric starting.

Cheers

**XTC** · 14th June 2005, 11:53

Originally Posted by Paul in NZ

Yes but is a GB engine the same (mounting wise) as an XR engine?

My theory is that GB400 motors will not be hard to find as everyone wants the 500... and some folk will want to put XR600/650 engines in to GB's anyway..

But a GB400 would provide a significant upgrade to a 250 and give electric starting.

Cheers

I think the GB motor mounts are different to the early CB/XR engines. Engine cases are definitely different. XR/CB has no oil filtration either (unless you count the mesh screen hidden behind the clutch cover) so very regular oil changes are a must on these bikes.

**vifferman** · 14th June 2005, 11:59

Originally Posted by Paul in NZ

It's an XR250 engine you say.... very hinterestin'

Would say.... a 'bigger' XR engine fit relatively easlily?? Maybe??

Indeed.
My XBR500RS Mutant was a CB250RS with an XR500 engine. The bottom is essentially the same, but the top end requires a cut'n'shut of the bottom of the fuel tank, the top engine mount on the rocker cover removed, and there isn't much rooom for the 500's carb (unless you use the twin-carb one).

And mine was OK to kickstart - even though the decompression lever was missing. Just fold the righthand footpeg up, find TDC on compression stroke, and kick it through.

**Paul in NZ** · 14th June 2005, 12:44

Originally Posted by vifferman

Indeed.
My XBR500RS Mutant was a CB250RS with an XR500 engine. The bottom is essentially the same, but the top end requires a cut'n'shut of the bottom of the fuel tank, the top engine mount on the rocker cover removed, and there isn't much rooom for the 500's carb (unless you use the twin-carb one).

And mine was OK to kickstart - even though the decompression lever was missing. Just fold the righthand footpeg up, find TDC on compression stroke, and kick it through.

And was it worth the effort???? I should imagine summat like that would be a bit of fun!

**James Deuce** · 14th June 2005, 13:18

Originally Posted by ManDownUnder

If I can paraphrase that to make it accurate...

more like the 500 would start kicking CSL (in the ankle...)

.... ouchies!

You guys who haven't met her - I doubt there is an organic or mechanical construct that she can't subdue - but then I'm scared of her.

**sels1** · 14th June 2005, 13:55

Originally Posted by Celtic_Sea_lily

Ionly to have her go "BANG!" and stop tonight.
:

Oh No CSL! just caught up with the news.. the new paint and seat was too bag a shock for her eh?

**Ms Piggy** · 14th June 2005, 14:32

Originally Posted by Jim2

You guys who haven't met her - I doubt there is an organic or mechanical construct that she can't subdue - but then I'm scared of her.

I knew those were the words I was looking for

Don't be scared Jim (much).

Although I'll confess to being the recipient of a rather large bruise, a week ago, on my right shin...after kickstarting my little beastie successfully many times, she decided not to play along. It was that kind of pain that causes silence (yup and this me we're speaking...not silent very often!) and then it goes in waves right through your body so that you are just about hyper ventilating.

Anyhoo - as far as the bike goes, I need to pull apart the engine and take a look. And well...errr...I dunno how to do that. So after exams I'll be hoping to ellicit some assistance from the fab KB crew I have been fortuinate enough to aquant myself with (I should be a professional greaser aye!).

**vifferman** · 14th June 2005, 14:53

Originally Posted by Paul in NZ

And was it worth the effort???? I should imagine summat like that would be a bit of fun!

I inherited it when it was in a bit of a sorry state, but with the engine already installed. It needed a valve grind, rejetting, new tahrs, and a complete repaint (frame, engine, tank, guards, etc.) So, I disassembled the whole bike, sent the head off to me uncle (engineering tutor at the tech), and got busy with the sandpaper and spray cans. Cost me $600 for all of that, and then I spend quite a bit of time fiddling to get it to run right. Lotsa fun, both the fettling/fiddling and riding (good wheelie machine). Sold it after a few years for $800.