arnout

Yup, ZRX shocks. Quite decent stuff for stock twin shocks (adjustable and good travel), but I'm keeping an eye out for something even beterer. The straight distance from the pivot to the shock mount on the XJR swingarm is about 485mm. At the time I made a sketch in AutoCAD to work out the position of the shock that would allow the suspension travel I was aiming for. Exactly. My goal with moving the top mounts was creating more suspension travel because I think that is the biggest downside to using twin shocks compared to monoshock. Some old twin shocked bikes only have 80mm travel (don't know the GSX spec. btw) but newer "retro" bikes are often equipped with longer shocks, at least the ZRX1100/1200 is. The increase from 110 to 125mm in my setup may seem hardly worth the bother, but I am quite pleased with the end result. Alternatively just using longer shocks (with longer travel) would solve the problem too of course (if you can find the space to fit them on the bike), but for that you might have to convert old motocross shocks or have them custom built. Why more travel? Apart from increasing the ride comfort, longer travel allows the damping mechanisms to work better (especially with lower quality shocks). (This only works of course if the spring is soft enough to actually use most of the suspension travel during operation.) Laying the shocks flatter will increase the force on the springs and so will compress further. There is a downside to this setup though. Although the compression/travel starts somewhat lineair, the angle of the shocks however changes during travel making the springs -relatively- softer. So actually the opposite of a progressive suspension.. Oh well.. The shocks haven't bottomed out yet though, but I am not a heavy guy and there are no pillion pegs on the Kat.

Like Blubber stated, the need for an oil cooler (a small cooler is stock btw) on an EFE depends on the use of the bike. If you live in a rural place and don't have dence traffic to deal with -which cuts the cooling effect of airflow a lot- AND the engine is stock AND you don't twist the throttle to the stop at every opportunity, THEN you can do without an oil cooler. I live in a big city however, and riding my Kat with stock EFE engine through the stop-and-go traffic will heat it up to around 105 deg. C. even with the stock cooler. Recently fitted a large Bandit 1200 cooler which brought the temperature down a lot. BUT the flipside of fitting a large cooler is that it takes longer for the engine to reach working temp., or it may not get up to it at all. Which is not good for wear. So.. That's why I also fit an oil thermostat with fitting a large oil cooler on my GSX's. As for the plumbing side of things. The oil filter plate controls the way the oil flows, and so is a vital part of fitting a cooler. The EFE plate blocks oil flow to the filter element and redirects the flow to the take off points on either side of the oil filter plate . An earlier (ET/ESD) filter plate lets the oil flow through without redirecting. Mike does a better explanation here: https://www.theflyingbanana.com/oil-cooler.htm I've got 2 stock EFE coolers gathering dust I am willing to part with in exchange for money, but I suggest you first read up on the subject and decide what cooler you actually need. And also of course figure out what size of cooler will actually fit the layout of your bike best before splashing your cash. I had a MAC exhaust on my old (stolen) Kat. It was very cheap, and it was cheaply made. Very thinwall (but big diameter) tubes, which actually made it pretty light in overall weight. The fit to the exhaust ports and around the bottom of the engine was spot on. Didn't use the muffler (which was heavy and hardly had any sound baffling). I painted the new system before fitting because the black paint it came with was worse than I thought.

Well.. If you swap the filter cover plate with one off an earlier 1100 (ET/ESD) it is, but if you don't and run it without an oil cooler the pressured oil has nowhere to go.. Not good..! Cool project btw.. I have a V&H on my own EFE, but not quite the same type as pictured above.. Also got it a lot cheaper as a used part from Eblag..

On my Kat I modified the shock mounts on its (GSX750EX) frame. The intention with moving the mounts was to position the shocks flatter to increase the suspension travel. Also the bolt-on mounts allow spacers to be added to adjust the ride height.

Ah yes.. Forgot about that can of worms.. Be wary of those Dynojet needles..! Because these were (still are?) not finished smoothly they wear down emulsion tubes (needle jets) much faster than normally would be expected. (Worn oval the tubes cause the fuel mixture to become overly rich especially at low revs, which is a familiar issue particularly on the Mikuni BST carb type series having been fitted with Dynojet kits/needles). The fix is simple: gently polish the needles smooth before fitting them.

Yup.. I once (long time ago) had a "stage 3" Dynojet kit installed in the BST36ss carbs on my GSX750/1170. I think it ran quite well apart from misfiring at the top end (which I later found was caused by using copper instead of suppressor leads with a Dyna2000 ignition). Don't remember whether I was still using the airbox back then or had fitted pods. But these kits are developed for specific bike models. Carb tweaking has already been done by Dynojet. So bolt on and you're in the ballpark carb-wise. So this won't work with non-stock carbs, and the dyno-operator-guy indeed spent a lot of time on getting the settings right on my GSX. Well.. It might.. If you put in enough dyno time to get the settings right. An experienced dyno-operator/carb-tweaker may not find any use for Dynojet parts in order make the Mikunis work well though..

Yup, earlier ET/EX/ESD sprocket cover fits onto the EFE lump, BUT as I've found on my EFE-engined Kat the gear change shaft is a bit shorter than on the earlier engines..! So had to machine back the protruding hole/shaft support on the cover somewhat so a sufficient length of the splined section would stick out for a lever to be mounted.

Sorry to butt in at this stage, but no the geometry looks fine to me. Mine is at around 64 deg. too, but you might think the fork angle would be even steeper looking at the picture: With swapping the stock front end for another one the rake of the frame needs to be altered to match the spec of the fork in the donor bike in order to also adopt the steering characteristics. If not, you will end up with a very slow handling bike. Stock EFE rake (or caster, or steering head angle) is 62 deg., but on a B12 it's 64.3 (and on a GSX-R1100L/M/N around 65 deg. I think). So.. to achieve this steeper angle the rear end needs to be raised as has been done on your EFE too. Using a B12 front end without any further geometry mods (and keeping the lower frame rails level) would result in the trail increasing by 15mm...! (that is, if I did my sums right..) Of course instead of altering the steering head angle / raising the rear one could also use a triple tree/yokes with a larger offset to compensate and arrive at the same trail distance. But as (more) modern forks are shorter, the raising of the rear end is also a way to regain ground clearance. Looking at pics of your EFE though it seems the B12 forks (which -as such- are of usable length) have sagged quite a bit. An EFE is a heavier bike than a Bandit, but still the springs might have weakened over the years and/or the preload might be wrong. So check the sag (20-30mm no rider load). Another thing influencing the handling and feel of a bike is of course tyres. Maybe the front tyre is very old, has worn square, and has perhaps developped a ridge you'd need to overcome when leaning the bike into a turn. When this the point of contact with the tarmac moves to the outside of the turn, it feels like the front is suddenly loosing grip. So I'd recommend having a close look at the roundnees of the front tyre before writing off the basic geometry..! One last thing.. Those handlebar levers seem to be set uncomfortably low..

Yup.. Like CC writes tachos on old Suzukis are often "optimistic", but aside from that I've always found the stock gearing on GSXs really -impractically- short. (From standstill quickly shift up to 5th and leave it there for 90% of the time. Lots of gear changing in city traffic, and revving the nuts off on the motorway. ) On my bikes I'm using 17/43 with a 18" rear wheel, which I'm happy with.

Good call. I see modifying the stock wiring and bypassing the light switch as a matter of "goes without saying", but of course it still needs to be mentioned. Indeed.. I say preserve the "character" you like (looks, sounds&smells, grunt, no frills, mechanical feel) and get rid of the "character" you don't. (crappy tyres, crappy brakes, crappy electronics, crappy suspension)

Have a looksee at thishere document: http://www.gs-classic.de/download/Suzuki-Farbcode.pdf I reckon it is probably 05L, but the problem is always that most paint suppliers cannot reference these Suzuki colour codes. This issue has been raised and answered several times before on this and earlier forums, so do a search.

If indeed you are a keen tinkerer or capable mechanic it is possible to pry the leaky seal out and tap in a replacement. New OEM parts can be ordered from various well knows online shops like cmsnl.com, robinsonsfoundry.co.uk.

Oops.. Failed to keep track of this topic.. Prim. gear ratio GSX750ES/EF/popup is 1: 1.896 Oil pump reduction ratio is 1.840 (91/48 x 33/34) which seems odd as this shows the oil pump is spinning slower on this plain bearing crank engine than it is on the roller bearing GSX1100 and GS1000.. Yup, as far as the GSX1100 ('80-'86) vs earlier GSX750 ('80-'82) are concerned, that's what I've always assumed and that's what the oil pump reduction ratio numbers seem to confirm. However the bike in question here is the later GSX750 ('83-'87) that has a totally different engine from the earlier 750. Still, both have a plain bearing cranks and both have similar oil pressure specs (3 - 5.5 kg/cm3 @3000tpm). How this similar oil pressure is achieved despite the higher pump oil redution ratio, I dont know. Perhaps the oil pump on the later bike has a greater volume? (different part.no's suggest different oil pumps between earlier and later 750). What of course stands out from looking at all the spec though is the massive difference in oil pressure between the roller bearing and plain bearing engines (GSX1100/GS1000/GS750 0.1 - 0.5 kg/cm3 !). Like you suggest I suppose the reason for this is that most of the pressure is "lost" via oilways to the roller bearings that offer little resistance due to their open structure compared to flow restrictive plain bearings. As a result the similarly constructed cams shafts on all of these engines have to make do with far less oil pressure on the roller bearing engines and so -I guess- worse lubrication. This is of course where the refitting/swapping of the GS/GSX750 (not: ES/EF/pu) oil pump gears onto the 1100 comes in. I guess though that restricting the oil flow to the roller bearings would have a greater effect in upping the oil pressure in order to achieve better camshaft lubrication. Nice pic to offset the long text

Nope.. Interestingly the NT and ratio of these later GSX750 oilpump gears is the same as the aircooled 1000 and 1100 engines.. (Perhaps the oilpump has a greater volume than on earlier 750/1000/1100 engines?)

Aw.. Well I did receive an invitation from CC but by chance that day I just finished rebuilding my Kat (and myself) after an "off" 2 months ago, and was very keen to try the bike and ride it on some twisties again until it got dark..

GS750 - roller bearing crank GSX750 - plain bearing crank So quite different engines (and prim. gears 99/46 vs. 93/43), but both sharing same the oil pump gears. Well-now-that-is-interesting-fun-fact: Prim. gears on the GS750 are straight cut, and were used "in the old days" on GSX1100 drag race engine to replace the stock helical gears when 1100-ratio aftermarket straight cut primary gears weren't available yet..

What indeed about the oil pressure warning light? Does it stay on? If so, ignoring it seems unwise to me.. The crank may need little lubrication -as has been said- but the cams do! There may be a perfectly good reason for the low oil pressure (if indeed that is the case) like a clogged oil strainer (pull the oil pan and the oil pickup to check) or a worn out oil pump. The low reading on the aftermarket(?) gauge may also just be the inaccuracy of the gauge itself. Also check the service manual for the actual pressure spec. Sorry to be the anorak here, but the oil pressures shouldn't be much different between the GS(X)750 and 1100/1000 engines as the different oil pump gear ratios are chosen to compensate for the ratio difference in primary gears. The clutch spins slower on a 750, and so does the oil pump drive gear that is attached to it. (oilpump reduction ratio 1100&1000: 1.723 (87/49 x 33/34) , oilpump reduction ratio 750: 1.642 (99/46 x 29/38) Oh well, pretty close..)

The what? Going by the further description I can only assume you mean the oil pressure switch? So the oval/diamond shaped thingy on top of the cases.. Yes.. Rubberised steel washers, but red copper washers will work too.

Thanks! To compensate to some degree for omitting the carb area "C" tubes I did add small gussets on the rear side of the frame down tubes where the subframe meets. I intended using K&N pods, but foam filters are pliable making the tubes you already put in much less of a problem. Btw the "B" tubes on my frame are chosen quite long making taking off the cam cover a bit of a pain, but it fits.. Just.. Also note the front engine mounts which are doubled up. A second set on the outside are angled back inside forming triangles. (Hard to spot in the pic.)

No issues whatsoever.. I braced the -GSX750 orig.- frame "everywhere" apart from the carb area just to avoid any issues, reckoning 3 stiff angles on a rectangle are enough to create a rigid structure (figuratively speaking). Also making the engine part of this structure was part of the plan. And the Kat does feel very rigid and precise on the road.

This here dowel/pin.. Works well I reckon..

These higher volume oilpump gears were fitted to both the 4v GSX750's (1980-1983) and 2v GS750's (1977-1979).

Better not be tempted to buy an OEM regulator if you want to avoid repeating the charging failure. Ah... I had 2 Electrex units breaking down on my bikes in the past. Now using Shindengen FH010ab and FH012aa regulators myself. Latest of these mosfet versions is the FH020aa. It seems the Shindengen "series" type (SH775 or SH847) is even better though, esp. with regards to resulting in a cooler stator

Quite right. It seems only the '83 GSX1100 engines had the different stack of clutch plates. Micro fiches: 1981 GSX1100EX 21441-49200 PLATE, DRIVE (friction) 9 21451-49200 PLATE, DRIVEN (plain) 9 1983 GSX1100ESD 21441-49210 PLATE, DRIVE (friction) 10 21451-49200 PLATE, DRIVEN (plain) 11 Haynes: friction plate thickness all modells exept SD, ESD 2.9 - 3.1 mm SD, ESD 2.15 - 2.35 mm plain plate thicknessall models 2.00 mm