Rebuilding a 1982 Suzuki gsx 250e into some kind of cafe racer. Now trying to get it running and having difficulties setting the carbs without the airbox. Came across one of your threads on the net and saw that I am not the only one having problems. So decided to join you guys to hopefully get it sorted. Any help would be greatly appreciated as I'm about to throw in the towel
Welcome to the forum. We'll try to help as best we can, but as the previous poster mentioned, it's very difficult to run CV carbs (successfully) without an airbox. I'm guessing you're going for the 'open' look with pod filters of some kind? Post a few pics so we have a better idea of your setup. Also, post some pics of the standard airbox; in particular, where it attaches to the standard carbs, so we can see if there's any velocity stacks or similar built into the airbox. You might be able to bastardise the standard airbox and build a mesh filter for it to make it look the part. In my (limited) experience, you have a couple of choices if you want to stay with CV carbs. You can have a bike that looks okay but will run poorly or, as @Murdo alluded, you can have a bike that runs well, but has an airbox, which isn't really a 'Cafe' thing. @maelstrom and others would suggest you move to non-CV carbs, but that will introduce different tuning issues and additional cost. Good luck.
Hi guy's, started on this some 4yrs ago. The bike has been completely stripped and rebuilt to a kind of naked/clean style, not what I'd call cafe. I had the idea that you would ride it with your best suit and tie on if you get my drift??? The airbox was tossed out years ago and the frame and electrics were altered. Could'nt go back to an airbox if I tried. So my only way forward is to come up with a magic formula with these existing carbs or go the VM route. 6 months have passed trying everything I can think of with these carbs. I realised early on that it was the air flow that was the problem, so I have tried lots of different methods of balancing it from too little to too much. Elbows/restricters/density/filters. My latest test will be needle on highest setting and a final increase of the main jet to 1.5, hoping that will give me a bigger window to balance the airflow with some further trickery/magic. You can tell i'm the eternal optimist........Frank
@Evo reported the magic numbers are 20 (pilot) and 150 (main), but I would be very surprised if it needed a main that large. The vac must be very low at high rpm to need a 150. I would suggest start at the 150 and go down in increments of 5 until it falters on WOT (under load of course) then go back up one size.
Hi all, bit the bullet and ordered a pair of Keihin 34 cr's at a mind blowing cost of £680. Good job the bike is going to my son. Will let you know how things turn out
Rang them this morning, they were going to use 31mm. I've instructed them to use 26mm. Hope your guidance will work. Thanks again guy's
