Motovalet Posted February 17, 2019 Share Posted February 17, 2019 (edited) I bought what was sold to me as a ‘97 carbed 750 motor.... it’s not! It’s a fuel injected 33E 750 motor complete with longer exhaust cam, different cam cover, different thermostat housing, three wire neutral/clutch switch, no carb take off point on back of barrels for carbs, cam shaft sensor etc. I have a set of 750 carbs and the correct 33E CDI. Am I correct in thinking if I swap out the thermostat cover for the 600 one, ignore the cam sensor, fit my 750 carbs (with vac pipe for tap), use my 750 CDI that it’ll run?? Secondly as an aside, can you simply swap out a 750 set off pistons and barrels and use the 600 bottom end, carbs, head, CDI and loom etc. I know it’ll be a strangled 750 but it would be a little more powerful than a 600! Or maybe use the 750 barrels, pistons and carbs with everything else 600? Alternatively can you drop 750 cams straight into a 600, any good or not worth doing? Thanks in advance! Edited February 17, 2019 by Motovalet Typo Quote Link to comment
Captain Chaos Posted February 17, 2019 Share Posted February 17, 2019 750 Carbs CDI will not plug into the 750 EFI loom. About the other questions, basically the 600 and 750 SRAD lumps are the same, with only minor differences. I guess everything can be swapped. Quote Link to comment
Motovalet Posted February 17, 2019 Author Share Posted February 17, 2019 I’m using the 600 loom, plugged right into the 750 33E CDI, basically just want shove carbs on an EFI motor and from what I can see, if I just use my 600 loom, stick coils and 600 thermostat housing whilst ignoring the cam sensor connection, it should run? Problem I’m having is finding some good 750 carb inlet rubbers! I’m wondering whether it would run ok on 600 carbs with stock settings too? In the meantime whilst I hunt down 750 inlet rubbers, I’m curious to see if I swap the 600 cams for the 750 cams (with cover to accommodate the cam sensor pick up) whether it’ll run any better? They fit ok and there doesn’t seem to be any piston to valve contact, what’s folks opinions on this, anybody done this? Quote Link to comment
dupersunc Posted February 17, 2019 Share Posted February 17, 2019 Leave the injection cams in, they are probably racier than the carbed ones . In addition to the bits you've mentioned you'll need to fit a carbed crank trigger and pick-up. I guess either the 600 or 750 one will work. The carb settings may need a little tweak to suit the injection cams. Shouldn't be a big deal to get it all working. Quote Link to comment
Leblowski Posted February 17, 2019 Share Posted February 17, 2019 Why do you prefer carbs ? I have a srad with carbs and would be more then happy to swap everything with you to get mine fuel injected. Quote Link to comment
Captain Chaos Posted February 17, 2019 Share Posted February 17, 2019 as far as I understand, OP has a complete SRAD 600 and bought a 750 engine to install, but got an EFI engine. Just the engine, nothing more. Quote Link to comment
Leblowski Posted February 17, 2019 Share Posted February 17, 2019 Srry my mistake didn’t read the post good Quote Link to comment
Motovalet Posted February 17, 2019 Author Share Posted February 17, 2019 1 hour ago, Captain Chaos said: as far as I understand, OP has a complete SRAD 600 and bought a 750 engine to install, but got an EFI engine. Just the engine, nothing more. Correct but I also have 750 carbs, airbox and 750 carb model CDI. As far as I’m aware no changes need making to the crankshaft trigger/rotar set up? The key thing I’m missing are carb inlet rubbers which is why I’m also wondering if it will run ok with the 600 carbs instead?? I’d also like any info on running 750 cams in 600 to see if there are any gains to be had doing this as an interim upgrade, pending full motor swap? Quote Link to comment
Motovalet Posted February 21, 2019 Author Share Posted February 21, 2019 (edited) Right, I cannot find 750 carb inlet/intake rubbers anywhere, only the EFI ones for throttle bodies! Has anybody got any experience of running 600 carbs on a 750 motor? Is there a big step in fuelling that will need jets to overcome or will they bolt up and work ok? In the meanwhile I have swapped my 600 cams for the 750 to see if there were any gains? Exhaust cam is identical in both motors, the 750 inlet is lumpier though! Set it all as if installing 600 cams, no piston to valve issues and fired right up, tick over is a little erratic but definitely feels as if the power has moved rather than increased? I guess to do this properly you need adjustable cams that can be properly timed? I’m going to run it until either some 750 carb rubbers turn up or I just decide to bolt the 750 motor in and see if it’ll run with 600 carbs! Edited February 21, 2019 by Motovalet Quote Link to comment
Motovalet Posted February 21, 2019 Author Share Posted February 21, 2019 Anybody tried 600 carbs on a 750?? Quote Link to comment
markfoggy Posted February 28, 2019 Share Posted February 28, 2019 Only thing that I can bring to this thread is that late Inj (750) cams seem to be same spec as kit cams for the early bikes. I had to clock some a while ago and was working from the Race Manual. So I guess a kit airbox and a set of flatslides would be good. Careful though, if you start to go in his direction you will find that nothing else will fit.....tank, radiator, etc etc Ignitech would be the perfect solution for any problems getting it all running. Quote Link to comment
Motovalet Posted March 1, 2019 Author Share Posted March 1, 2019 (edited) Well, inlet rubbers for a 750 are just not available? So, I’ve dropped my 750 fuel injected model cams into my 600 motor, timed them up same as the stock 600 ones and it runs fine! A little bit fluffy on tick over but definitely feels more responsive than before. Ultimately what I’m going to do next is drop my 600 head (with 750 cams) on to my 750 EFI motor and run the 600 carbs. I’m not 100% sure on this but I may need to swap the ignition rotor too as apparently the EFI timing is different? I’ll use the 600 loom and a 750 carb model ECU too. Only real issue I can see is that the 600 carbs may need the needles height altering or possibly bigger mains?? What’s the “kit” airbox, where do I get one and what’s “ignitech” too please? Flat slides are out of my budget just now but I may look at titanium header pipes from a later K model to mate with my Scorpion can which morphed into Akroprovic at a later date but they are essentially one and the same. Edited March 1, 2019 by Motovalet Quote Link to comment
Madb Posted March 2, 2019 Share Posted March 2, 2019 “ignitech” is a company that make ecu and other electronics goodness. Very good on prices too! Google them Or give @dupersunca shout. he'll put ya straight. As for the "kit" Airbox. It's a airbox made for the racing bikes from the factory. You may find one or ask mark if he would look into it for you? https://www.Eblag.co.uk/i/401718074088?chn=ps. Don't know if these are any good to you,Sir. Quote Link to comment
dupersunc Posted March 2, 2019 Share Posted March 2, 2019 No need for an ignitech. the stock cdi will be fine with the right crank trigger. Quote Link to comment
jonny1bump Posted March 2, 2019 Share Posted March 2, 2019 There are some on the bay for £24 each. Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.