Motovalet

Does anybody know why my carbs would be stamped with what appears to be “PBS” and why they would have what appear to be ridiculously small jets at 112 carb number 1 and 4 and 110 for 2 and 3?

I’ve given up trying to get my GSX750ES to fuel properly with pods and my Yoshimura replica four into one and have decided to re fit an original airbox along with a Marshall Deeptone four into one which apparently needs no jetting? My question is, does anyone know the original carb set up with regards to main jet, pilot, air corrector jet and needle clip position, also air screw turns?

So, today I dropped the needle circlip to its lowest setting and also put a shim under each, air screw settings now 1 and a half turns out, still using two RAMAIR sock filters over airbox to carb inlet rubbers. Fires up, idles nicely, revs cleanly and no flames, no spitting and no backfiring! All on a bench so subject to real-time later road testing but I’m mildly confident it’ll be better!

So, as zip interest on my Schwantz tribute GSX750ES, I’ve decided to try and get it running sweeter and get it tested so I can ride it for what’s left of the Summer! The current settings are:- Main Jet 120 Pilot Jet 45 Air Jet 155 Needle 15D10 Second clip from bottom Air Screw 2.25 turns out It starts and idles, picks up but backfires and spits flames at WOT throttle, which suggest to me it’s lean and maybe needs a bigger main or the needle lifting to the last clip? There’s already a shim under the clip so moving it and using the shim is a reasonable lift. The original main jet was a 110 and the rest of the set up on the bike the carbs came from was four into two into one exhaust, open can, same as on my bike but it ran K&N pods rather than the RAMAIR sock filters I’m using over the original airbox inlet rubbers used as velocity stacks. I’m wondering if the K&N’s would be more restrictive on air flow than the sock filters, hence running lean? I welcome all input!!

Bugger! Carb tops foul the tank! Might just stick this motor in an old teapot frame I have instead now, a lot less work! Not really wanting to get into tank notching and the motor can’t really sit any lower in the frame?

Done this on a SRAD too and worked like a charm!

So I’ve had this for over a year now, not my build and tweaked it here and there and sorted a few issues but really want to make the bike “my bike” and put my mark on it. I’ve been chatting with FBM discussing a turbo and I’m kind of thinking that’s the route I’ll go down but also looking at alternative ways to improve performance, looks etc. and pricing up flat slides and some proper dyno time? Either way it’ll be getting fresh paint. Interested in real world road experience of a turbo install and nice carbs. I’m well aware of the dot head, cams upgrade etc. as well but there’s no room on this build for the carbs to fit on the dot head and besides the complete short stroke 748 motor is now in my GSX750ES!

Yes that’s what I’m thinking? Looking at the Black Widow headers for the 750 teapot, nice looking and like you say get a custom link pipe and a cheap SC Project Chinese knock off can with. Yoshi badge…. Job jobbed!!

Plan is to replicate my original one that I regret ever selling! I still have another one with stock motor but Blandit wheels etc. built as a nod to the AMA Yoshimura Schwantz GS700E. Pic of both attached!

Bit of an update….. now wrestled in the Slingshot motor, managed to make use of the two original rear engine mounts (top and bottom) but will need new front plates. Not 100% sure what headers will fit or if the engine might need tilting forwards or backwards? Pretty sure GSX750F headers will fit? Anyway it’s underway!

Latest purchase! Came with original exhausts and is pretty much all there but needs a full going over. Can’t decide whether to restore to original or, slot the spare dot head 750 slingshot motor in along with later wheels, Blandit forks etc. and fresh paint?

I’m trying to get my 750ES to run with either K&N pod filters or Ram Air sock filters on OE inlet rubbers. I know using the airbox is the “correct “ way but that’s not an option as I don’t have it and can’t find one for sale. Carbs currently have correct jet kit fitted, looks like a Dynojet or similar? Bike will start, idle nicely and rev up fine in the garage. Once out on the road, it’ll struggle to go faster than 40MPH and runs like a pig, it definitely feels like the slides aren’t lifting enough. Is there any way of getting these carbs to work without an airbox? I note the slides move a lot stiffer compared to later carbs off of oil boilers, BST36’s etc. these all have flat slides and a softer spring, is this the issue, are the springs too stiff? Conversely my Blandit engined Kawasaki runs absolutely fine with jetted BST36’s and Ram Air filters so I know it can sometimes work! All input appreciated!

I gave up and left it be! I’m more interested now in fitting a 750J motor into a GSX750ES frame! In particular mounting plates? Possibly even into a 550ES frame, although this looks like all existing mounts will need chopping out and new ones welded in?

I’m trying to get this B12 motor out of a GPz1100 frame with little joy and lots of scratched tubes! Am I right in thinking easiest way is sump off and cam breather off or even possibly the whole cam cover? The reason it’s got to come out is because of the dubious engine mounts which need improvement and the fact I’ve a short stroke dot head 748 GSXR to go back in its place!

All wired up now! Spare green and white wire was for oil pressure switch!

As per title. Wiring my bike from scratch and need info on correct CDI wiring please? I’ve deduced feed to coils and ground but need specific information on wiring the kill switch and what is the green/white wire emitting from the pick up wiring as it enters the CDI? The stock wiring sends this up to the OE clocks and when connected it lights the side stand and oil light? It seems to be a positive cable? I’m binning the OE clocks and just running a rev counter and GPS speedo. Is this green/white a switched positive to power the CDI and coils? Lastly, how do I wire an electronic rev counter from the coils please? TIA

I know! I’ve one on my GSX550ES and actually have a complete spare GSX600F front end. I want to keep my build as authentic to the original race bike as much as possible which is why I’m keeping the front end, anti dive and single sliding callipers. I think there’s no way around it other than adaptor plates!

Having re-measured my existing callipers they’re definitely 70mm centre to centre so ply wood template brackets and then some alloy cut and drilled to match is the way forward!

I’m after some base settings to run individual K&N pod filters on stock CV carbs. I need to know air/fuel screw turn out amount and baseline main jet sizes? Currently I have 120 mains and fuel screws two full turns out, but I’ve yet to fire the bike up as it’s not finished! I’ve no idea what the standard main jet size is as I can’t read it as it’s just too small for my ancient eyes! I know CV carbs aren’t ideal for pods but that’s all I’ve currently got! I’ve heard using the original airbox to carb intake rubbers and sock filters may be a better option? Anybody got any real world experience of this? TIA

Will do! Thanks for the heads up!

Mine are 70mm centre to centre from what I can tell? I think it’s adaptor plates or nothing!

Well, I’ve had a look at that and I’m not sure I’m reading it correctly? My ‘98 SRAD 600 callipers definitely don’t fit my GSX750ES, yet both bikes are in the list marked 1? Or, is it the Kawasaki and the Triumph will fit all the Suzuki’s listed??

Reet.... had a good root about and can’t find any definitive answer to my calliper swap quandaries. I’m part way through a Yoshimura GS700E Schwantz tribute build using a Jap import GSX750E as the base bike. I’d like to keep it fairly authentic with running gear and so far have Bandit MK2 wheels front and rear already in situ. Before I resort to adaptor plates on the front forks, does anybody know of any callipers that would bolt right on up allowing me to run the “Blandit” brake discs? I’ve had a go at measuring the bolt holes centre to centre and I reckon it’s 700mm? Thanks in advance!

I like the idea of fitting an air cooled GSX750ES motor into a GSX550ES frame. Both frames are visually similar but I think the 550 might be too narrow and too low between the top and bottom rails? Does anyone know if it does or better yet anyone done this swap? I know an oil cooled motor is smaller but I’d like to stay aircooled!

So, here’s how she stands right now whilst I decide whether it’s worth the aggro of getting my EFI 750 motor to run with a carbed 750 CDI, 750 carbs, 750 airbox and my 600 loom or to shove my 600 head on the 750 motor with the 600 carbs, 750 CDI and 600 loom? Currently I have the stock 600 motor running 750 EFI cams, inlet and exhaust, airbox wrapped in heat resistant tape with crankcase breather tube pulled from airbox and venting via a filter direct into the atmosphere, with original airbox breather hole plugged appropriately. Scorpion/Akroprovic can, billet alloy top yoke with risers and Renthal bars, cut down fairing panels as necessary, ZX10B footpegs, keyless filler cap, braided lines and new levers. She goes very well in the current set up but I’d love to make use of my 750 motor. Unfortunately as it’s an EFI one and not a carb model, there’s all sorts of niggly differences that I can’t seem to find definitive answers too? Mainly around, timing differences, ignition crank trigger rotor and CDI’s. It’s definitely NOT a straight forward swap, despite what the internet says!!