Motovalet

I have clean working set of 38mm Mikuni BDSR carbs that came off of my "Fader" 600. They were jetted to suit that bike running a 4-2-1 system and individual pod K&N type filters. Will these carbs work best on my 750M motor which will also run a 4-2-1 system and either individual or twin pod filters per carb, or am I best using the Mikuni 36mm CV flatslide carbs that came with the engine? I've read that the 36mm carbs are a good choice but I've also heard and read people rate the 38mm carbs?

So do I just need to source a suitable big bore slip on can then do you think?

Does anybody recognise this exhaust system? It came with a 750M motor I picked up and both were once attached to a French 750 "Teapot" (GSX750F). It says "Nikko" on it but it looks a bit like an old Piper or Alfa four into one except this one is a four into two into one system. It looks like it has a baffle in the end and it's a complete system rather than needing a link pipe and a can, i could be wrong though? Anyway it needs a bit of weld to a crack around the collector but it it's a decent pipe I'm going to put on my 600F/GSXR750 project! :-)

I'm near Northleach, just off the A40 (Chelt to Oxford). More than happy to take you up your offer of help when the weather picks up, you wouldn't want to be riding down the shitty muddy track that leads to my place at the moment, you'd need a crosser or a 4x4!! I removed the sump today and it's all nice and clean in there, the oil strainer/filter mesh thing was clean as were the oil feed pick ups, the thing I'm too happy about is that when you look up the exhaust ports the stems of the valve guides are real cruddy, I blasted them with carb cleaner and did the same on the carb inlet ports as well as the stems were a bit mucky here as well. I also poured a little oil down the bores through the spark plug holes and turned it over with a socket on the end of the crank all seems fine and I'm going to stick with your advice for now i.e check the valve gaps, fresh oil, filter and plugs and then pop it that frame (that's where you may come in helpful!) what I need to do next is strip and rebuild the 36mm carbs I picked up and find a cheap exhaust system. I've got a set of headers that are four into two into one but there's a crack at the collector that needs welding and I'll still need a link pipe and an end can, money's a bit tight at the moment and not set to improve much until this bloody rain stops and there's a little more work about! One other quick question, do you reckon it's be ok to re-use the cam cover rubber gasket or get a new one??

Perfect! Many thanks :-)

Ok, thanks for that. Don't suppose you'd happen to know the correct inlet and exhaust valve gaps? :-)

Yeah, shims, groan! Need a spring compressor as well as a compression tester now then! Here's my output shaft, you can see the small sheared bolt right in the middle of the shaft. So I need just the nut and a tab washer then?

Cool! That's great news, so better than a 750F motor then? The 750M's are supposed to make 116BHP and I think the short stroke dot head 750F is around 106, not a lot in it but hopefully this motor will be quick enough. It's certainly better than the wheezy old 600F lump that it's replacing! I've never heard it run and took a chance on it, it turns over and all the cam lobes look good and the inlet tracts are clean as are the exhausts. When you look up the ports (either) the valve stems look very black and rough looking but hopefully just carbon build up?? I poured oil down the bores and squirted carb cleaner in the inlet and exhaust ports and it also looks like somebody drained the sump as it was empty, the oil that was left looked clean enough though. I'm optimistically hoping I can do a compression test, gap the valves, add new plugs and fresh oil and hope it fires! Is there anything glaringly obvious I ought to do before it goes in the frame that I may have missed? The only two negatives I've spotted are 1) the there's a sheared bolt right in the middle of the sprocket output shaft, I'm guessing it's some kind of retaining bolt although the shaft itself is threaded after the splines which suggest a fugging big nut goes on first? If so can I just leave the tiddly sheared bolt alone? 2) There was quite a lot of rust dust that fell into the bores when I extracted the stuck spark plugs and I'm hoping it'll just get blown out of the exhaust and not do any serious damage?

I've got hold of a 750 motor that came out of a GSX750F (1990) but it looks like a GSXR750 motor? The clutch actuating lever (where the cable connects) is on the right hand side, like on the 750J and there's a a dimple in the clutch cover, I'll upload a picture when I've taken one but hopefully this engine number may identify it? It's R716-101635 or the last digit may also be a 3?

I'm in Gloucestershire so a fair way from mid Wales, but thanks for the offer :-) A couple of people have said it is easier to bolt it to the lower cradle first and then jack it up and bolt it in? Sounds easy but your dead right with that sump plug smack bang where you'd want the jack to be will make it a proper ball ache! It's not going back in the frame until I've checked the motor over, cleaned it up and painted it so I've got a few more weeks to figure out the best way forward.

Well, I'm on my own when it comes to fitting my engine back in the frame and ideally I hadn't planned on having to unbolt the front end and the rear swinging arm etc. I was hoping to put the motor on blocks and maybe remove the front wheel and secure the bike to a joist via a tie down so the forks were a decent height off of the ground and then kind of lift the front up pivoting the bike on the back wheel up and over the engine, not sure it'll be that simple now though tbh! Be so much easier if there weren't those bloody great big side frame spars. I once put an old EFE motor back in the frame by simply lying the motor on its side and putting the frame over it, nice and simple! Your finished sleeper looks brilliant though and if you ever get up to the Ponderosa Cafe, Horseshoe Pass in wales or to Lynn's Raven Cafe at Prees I'll look out for you :-)

Excellent! All in all you've had a right royal result by anybody's standard! What you need now is a wider rear wheel, maybe out of a GSXR of some sort and a Bandit 12 swinging arm and whilst you're at it an upside down front end, that would look like really trick teapot!! :-) Thanks by the way for the advice on my 750 engine overhaul, I'll heed your considered wisdom and check the valves, cam chain, do a compression test, bung in fresh oil and plugs and go for it! Turns out the 750F motor I bought as 1990 750 (and therefore a short stroke motor) is actually a 749cc long stroke motor, it definitely isn't a later 750F and seems to be a much earlier GSXR750 motor, possibly a slabbie? it certainly looks scruffy enough to be that old! Plus I have some 36mm carbs that need a full rebuild, anyway it won't be as powerful as your sleeper build but should still be quick enough for me. My other current ride is a boring but nicely modded and 'fightered 600 Yam "Fader" and so long as it puts out similar power (around 95BHP) I'll be happy. It's all relative at the end of the day as this time last year I owned a seriously quick blue printed gen one 1300 Hayabusa and frankly any bike after that will always feel diluted, but I reckon in the real world on todays roads an old teapot 600 kicking out hopefully nearly a 100 ponies should be plenty, time will tell! One more thing whilst I have your attention lol, when refitting my lump, as I don't have your nifty engine hoist, do you reckon it's better to bolt up the motor to the lower cradle first and then maybe use a jack to somehow manoeuvre it into place? I nearly broke my bloody back lifting the thing out of the boot of my car the other day and I'm not looking forward to putting it back into my nicely repainted 600 frame for fear of scratching it all to buggery!

Well impressed that you got this project on the road so bloody quick! Respect too for the fact that you did it all outside as well! I thought I was hard done by having to work in an unlit, unheated damp timber garage but now I think I'm spoilt! Anyway, my 750J motor is goosed and I'm not sure which bits are interchangeable with the 750F motor I have so I'm going to chance my arm at installing the 750F motor for now. The thing is this motor has not run for a while and has been languishing outside for a while, I want to refresh it as best I can before installing it in the frame so it has a fighting chance of starting and running! The oil looks clean and the engine turns over by hand fine. Before I strip it down I'm after pointers on what I'm likely to need to replace, stem seals, rings, gaskets etc.? I've decided to buy a compression tester and check compression on all four pots, I've no idea what the readings should be but I'm guessing if all four cylinders are the same or there or abouts then there's no real need to take it apart or replace anything, am I right or wrong? As you've obviously got experience with the 600F and the 750F I'm hoping you can give me a few pointers! :-)

Wow! You didn't hang about getting that sorted! Mine is more of slooowww burn! It's on it's wheels, engineless and awaiting a new donor motor. The 750J I sourced is totally goosed and needs a full rebuild :-( Meanwhile I've sourced and entire 750F teapot for £150!! Motor is dead as the bike has stood outside for a good while but has clean oil and turns over so I'm toying with fitting new rings and stem seals and taking a chance on using this instead or maybe combining the top end from the J motor? That said I've had a very tempting offer on my two smoke Suzook X7 that would fund the entire build with the original planned donor motor of an 1100F like yours!

Excellent! Looks like you've made a lot of progress. I've chickened out and bought a cheap as chips 750 motor (dot head, short stroke 750J) that may need rebuilding but should still hopefully give the bike a decent power hike!

Yeah, from digging around a little further it would seem that the 750F motor is actually a GSXR750 motor anyway but from an older model, and yes you're right everybody says it's an underrated motor and actually plenty powerful in the real world. They also seem a lot cheaper, coming in at around £300 plus another £100 or so for the right carbs. So, I've decided that unless a very cheap 1100F or B12 motor comes along early next year then I'll be shoving a 750 in the old girl! It might be a full on mega sleeper but even with a 750F motor in it and a decent pipe I reckon it'll still catch a few crotch rocket pilots out! I'll be posting pics of either route as I progress and I look forward to more instalments of your project :-)

Thanks for the heads up on the KatRiders forum, I've already read that and spent far too long researching the ups and downs of the proposed 1100f swap than I care to remember! One thing that you may already know is, you don't need to chop the frame to accomodate the breather box on top of the rocker, you can swap it for one off of the teapot 600 as it's slimmer and as far as I know you don't need the top/tank brace either? I put a power screen motor in a Bandit 12 once and it was all very straight forward which is why I thought it would be easy to put it in the teapot motor. My 600 is a 1990 so it doesn't have the TPS on the carbs. I'm thinking a lot more about the barrels form a long stroke GSXR750 now and maybe the head too, it's the cheapest option for me to be honest and the 600 motor I have has high miles at 50,000 but the motor was very good and has a known history so it kind of makes sense. The one think I need to clarify is whether the power will be similar to a GSX750F because if it's not then the full GSX750 plug and play swap may be the way forward as these motors can be picked up for as little as £200! The only other thing I may do is use the swinging arm from the 750F and the rear wheel as the wheel is wider and the swinger is longer, important considerations if I end up sticking an 1100F motor in there! look forward to your post Christmas update, be good to see if you can make it all fit, post some pictures! :-)

Watching this thread with interest as this is exactly what I'm trying to do at the moment but I'm not as far along as you, in so much as I don't yet have a donor motor! Everything else is good to go, painted the frame, swinging arm, wheels, replaced every bearing, swapped out the old teapot 600 shock for a VFR400 one, fitted progressive springs, rebuilt the brake calipers, replaced the steel clip on tubes with alloy ones, binned the centre stand, sorted braided brake lines yada, yada etc. etc. All the 1100F power screen motors I find are £600 minimum which is more than the whole teapot stands me in at! I considered a teapot 750F engine swap like you've already done at one point as they go for a lot less, but now I'm looking at putting long stroke GSXR750 barrels on to the teapot 600 bottom end as this is cheaper still, just not sure if the power hike is great enough to warrant the effort? It may be that if this works I'll do it just to get the bike back on the road until the cash cow comes home to allow me to buy a power screen motor Anyway, like I said I'll be keeping an eye on your progress, good luck :-)

Well it's that time of the year again when cash is scarcer than a scarce thing! I've got the teapot up to a stage now where the only thing that's holding me back is a suitable engine at a sensible price. I've found a couple of cheap as chips long stroke GSXR750 barrels and pistons for sale and considered advice has informed me that a long stroke 750 will fit the teapot 600 bottom end and that I can even use the teapot head and carbs, all sounds just too easy? I've also been told that if I do that the "new" 750 pistons may well hit the head, somebody else mentioned cometic gaskets which are apparently thicker and would alleviate this but they're not cheap! Looking for a definitive here if anybody has done this or is doing this can they show me the correct route? Is the hassle worth it, ie what sort of power would I end up with? Got to be more than the wheezy 70-80 BHP that the 600 teapot puts out? Failing that the final and most drastic plan is to sell my old Suzook X7 stinkwheels for a pile of cash and bite the bullet and shove a nice 1100F or B12 motor in there as planned all along! :-)

Thanks for the input, especially the idea of putting a GSXR750 top end on the B6 motor, I've had a look around the net for more info on this and found a little info on a Bandit forum. This seems a worthy option given I've already got the complete Teapot 600 lump on the bench, other than that unless a cheap 1100 comes up then I reckon the 750F motor with bigger carbs may be the way forward. I was also originally trying to keep the stock look but again for cost I'm now considering the cafe racer look or the dreaded "streetfighter" look :-) I'm trawling the net for inspiration!

After much more knuckle skimming and general fettling I've decided to pursue this build but with a cheaper engine, there seems to be a lot more GSX750F teapot motors knocking about for around £300, so I reckon one of those with a decent exhaust system and maybe bigger carbs might give a noticeable hike in power over the stock 600F motor. I guess with hindsight it might of been better buying a GSX750F bike in the beginning but where's the fun in that! I even wondered if there was any mileage in fitting 750 barrels and head on the 600 bottom end or mixing it up with some GSXR750 engine bits, like cams from the 750J?? Any input gratefully received :-)

Well, having a bit of a re-think now and probably going to refresh the 600 motor and stick that back in and finish up with a nice stock restored teapot but with better suspension. It's just not looking cost effective to source a suitable motor as for that kind of money you can almost buy a whole bike! Got my eyes on getting an old early RG125 instead, just fancy something a little smaller and rarer, done the whole big bore bruiser thing and fancy going back to the days of wringing the neck out of a small capacity stroker and keeping up the old corner speed :-)

Thanks for the info. That sounds a much better idea, what exhaust system do you run and have you used an airbox or pod/K&N type filters with the 38mm carbs and if so can you remember the jet sizes and settings at all? My bike is now on its wheels with a VFr400 shock in place of the stocker, new bearings throughout, cartridge emulators in the stock forks and now needs the motor, wiring sorted and the bodywork spraying although I haven't ruled out carbon wrapping the bodywork and the tank but I'll need to get the seat recovered as it's bright red! I did read on the Yank based Kat Riders forum that it's actually possible to paint your seat, I know that sounds absurd but the thread on there is really interesting, but probably just as easy to have it recovered. I'm sticking with the stock brakes and skinny wheels for now but with braided lines and decent pads but may re-visit that once it's finished and running. I'd like to post some pictures of the build to date but every time I upload them I'm told the file size/image is too big and I don't have anything on my steam powered laptop to reduce them! :-)

Ok, cool

Well the GSXR shock I have no way fits and I now find out that a VFR400 NC24 fits and is 10mm longer eye to eye so that's that sorted (hopefully) here's the redundant shock. I've decided to keep the original skinny wheels for now largely due to them having to nearly new Bridgestones fitted plus I'm trying to stay faithful to the original bike as much as possible baring the bigger motor, it is ultimately to be a stock looking "sleeper". I've replaced all the bearings in the wheels, swinging arm, headstock and all the shock linkages so that should tighten everything up. In the front forks I have some nice but expensive cartridge emulators to bring them a little bit more up to date. I really like the Whitams bike and think that paint job would really set the bike apart. The biggest headache is trying to find a decent B12 or 1100 powerscreen motor complete with carbs. There's a few on Eblag but £600 plus, really??