Camshafts, Jets, and Other Follies

[Falk]

Wow - schould the camshafts make that difference?interesting

[rigwit]

I used 35/110 Jets in the past.
I removed the snorkles and replaced them by some Plastik pipes with 4cm in diameter
( Waste Water pipes for Bathrooms and Kitchens and so on) like in the Picture.



In Germany we call them DN40, you can also get DN50 (5cm) and in different angles from 15° up to 87°.
At the Moment I'm using DN50 87° ones, but i need to play with the Main Jets. My Bike is still running to rich because of my exhaust system. No one can explain this to me. why the bike is running richer with a complete system (laser-system). Only thing I know is that there was also a BOS-System incl. Downpipes that was shipped with 103 Mainjets.


Think you misunderstood me when I referred to my, "snorkels"  I am talking about the carb's bell mouth snorkels not air filter case intake ones,  I am doing away with the whole original filter housing and having a filter made to mate to my alloy baseplate...........it will then be a case of fitting to spare carbs quick balance on bike, take off then use the one's on now, n  take with me to dyno----------first test stock carbs with original filter----------find the best overall result on those-------whip them off-------- uses spare carbs which remember will be already balanced with my custom air filter on-----back on the dyno to see what happens and if needs bigger jets place is a bike dynojet dealer so hopefully will get it sorted..

[a_morti]

Falk, I did misunderstand about the corners but think I get you now. Not sure why you do this, but it's your bike so have fun

Wow - schould the camshafts make that difference?interesting

I think the cams make a lot of difference. When you hold both parts in your hand it is very easy to see that the nc23 cams will hold the valves open for much longer. I think that they represent one of the biggest differences between nc23 & nc27, which as we know the difference is around 15hp extra, largely at the top end. The rest then comes then from the CBR's 4>2>1 downpipes, bigger airbox, slightly higher compression, ignition timing differences and jetting to match.

I think after I get the fuelling close enough, I might be tempted to try a CBR CDI unit. This would really depend on what the power curve is doing. If it's still climbing or at least still strong towards the top, it might be worth having a few more revs to play with. I think this would require a swap to the matching CBR ignition pickups. Maybe it's good for a couple more (cheap) hp? It would raise the rev limit by 1,000rpm I think, as the CBR's rev limit appears to be 14,5k. The extra 1k on a standard CB-1 engine aren't worthwhile as the cams can't breathe enough at this speed anyway, I believe. Meh, it's all guesswork until  I try it

[Falk]

Falk, I did misunderstand about the corners but think I get you now. Not sure why you do this, but it's your bike so have fun

You know the discussions about just taking away the Airboxsnorkles. It makes the bike stotter. But with bigger Jets, I also need to get more Air into the Engine. - the original Snorkels a´have a Diameter form around 36mm (I can't remember right now). So I replaced the Snorkles by this Plastik Partcs to get the nice constant Airflow the CB1 needs. But with the longer Opening Time from the  NC23-Cams it seems that this Mod is not neccessary.

BtW.: I'm testing this with a oxygensensor i weldet into the downpipes. (no Dyno in my Area for a normal Proce available).

[a_morti]

Yes, I think you could fit 4" snorkels and the cams still wouldn't be able to allow much more air mix through the system.