gs7_11

Here you go!

Well, here's an update, might be useful for anyone who has a similar issue. Float bowl vent pipes. I still had this slight hesitancy with 45 pilot jets. The bike was as good as it had ever been, but not quite right, and I began thinking needle and taper. That leads you to Dynojet, but it really irks me to pay £130 for what amounts to a needle. However I got a kit for £80 from Germany after a bit of searching. So, to get a baseline, went back to standard first, then fitted the slightly bigger main jet, drilled the slide and fitted the needle. All seemed good at first, low rpm throttle response much better, and the bike definitely is more perky. Still got a slight hesitancy at about 70 though. Aaaargh! Read the trouble shooting guide.......make sure float bowl vent pipes are removed it says. I was sceptical......they are as standard, sitting in still air at the back of the Airbox, what harm could they do? Anyway, takes them off, problem solved! Went for 100 mile ride to celebrate! The Dynojet kit is money well spent, as now the jetting is bob on in the mid range, and I'm not trying to compensate for leanness there by using bigger pilots. The bottom end can be leaner, so the idle is perfect and the low end throttle response is great. The trouble shooting guide has a great diagram showing the overlaps of each part of the circuit, and how much effect each part has, very handy.

Can't comment on the others, but I've had mixed experience with Wiseco 1085 kits. On one hand, I've got a kit in my 7/11 which has been in for years and 25,000 miles (at a guess) and is still tight, pulls well, burns no oil. Another kit I had, I found a circlip had receded into its groove, allowing the gudgeon pin to come out and damage the bore. After some toing and froing, Wiseco gave me a new kit at cost price for that.

Wow that master cylinder looks like it's had a hard life! Is that a copper crush washer embedded in the end? What's the cylinder bore like? With any wear or scratches there, together with those goosed seals, you'll be lucky to get efficient pumping. Like you say, all the holes need to be clear too.

Yes, only GS1000 it could be is L pseudo chopper.

They've started making green Duckhams again for the classic car boys!

Well?

Yep. Keeps the brain ticking over!

Well, I lifted the needles, as that's easiest. I swapped the little plastic spacer for 3 x M3 washers, raising the needle by 1mm. It was a little better, but mainly at the top end of the original issue...so, pilot jets? Yes. I had a set of 42.5s (stock is 40) which I fitted, and the improvement is marked. Not 100%, but I've been able to back the pilot screw down to 2 turns out so the idle is much more stable. The hunting is 80% gone, confined to about 50mph, and much less than before, anything above that is clean and steady. I've bought a set of 45s and will try those, hopefully that will clear it up completely. These carbs were set up very lean as stock. Emissions laws in US?

In which case it's almost certainly camshaft end float. Are you willing to strip the top end just to confirm what everyone is telling you anyway? BTW that chap's noise was horrendous and his buckets clearly worn, never seen one that bad. I would say that 750 had missed more than a few oil changes!

It's not an air leak. I've replaced the o-rings on the intake stubs, and the rubbers themselves are in good nick and well clamped. Oval emulsion tubes, well, maybe. But both sets of carbs? I've examined them closely and can't see anything. The needles aren't worn, and both sets of carbs are in good condition, imported form the US and don't look like they've had that much use.

Only indirectly. Opening the throttle causes a change in differential pressure that is felt by the diaphragm, I know that. However the slide will only rise as far as the pressures in the choke will allow it, requiring an increase in RPM to change the relative pressures, and complete the demanded operation. So, yes, in a steady cruise, the slide will equate to throttle position, but unlike with a slide carb where you can state categorically where the slide is, it's not so clear on a CV carb. http://www.factorypro.com/tech_tuning_procedures/tuning_carbtune,CV,high_rpm_engines.html I guess it's mainly terminology, but on CV carbs I think you're more accurate referring to RPMs.

Thanks. I'll try that. Bit of a pain as the height on these is set by thos little plastic blocks so Ill have to improvise.

You can't. Well, you can, see the above posts re: The GS Resources website. Have you checked that out yet? The fix is laid out clearly on there, have fune if you want to do it Seriously I'd suggest you leave it alone. Also, don't touch the cam chain adjuster. It's automatic, and unless it's failed completely (you'd know about that) it requires no attention.

Yes. Well, near as I can tell. Same part number, jet sizes etc and both sets have been ultrasonically cleaned. Valve clearances were done a couple of years back, but not many miles since.

GS1000 engine, Mikuni BS34 CV carbs. Runs well, but getting a bit of hunting at steady 4000 rpm cruise. Assuming everything else is ok, lift the needles or bigger pilot jets? (Standard airbox, Wiseco 185 kit, Kent cams, Eagle 4:1. Have tried pilot screw adjusment, but no difference. I have got 2 sets of carbs and get same problem with both. Online guides talk about float heights, but I reckon that is ok, have checked.) So, being as CV carbs work more on RPM than throttle opening, are we on the needle by 4000rpm?

The update on this is: no go. The bloke who was doing it got a quote of about 85,000 Aussie Dollars for a minimum order of 2000 pairs. Originally he was hoping to be able to get only 500 pairs done. So it's not happening. Not only that, apparently they wrecked one of his brand new NOS mirrors in the process of reverse engineering them.

Echo.....echo.......

If it's cam end float, just live with it. Sounds like it may be, and there's no need to worry bout it. There is a proper fix, but its not really worth bothering with. Check out the GS Resources website. Balance the carbs - that will help with noises, however do all the other service items first, including shimming the valves. These are not quiet engines! By the way, if the charging system hasn't been sorted, make sure you ride with the lights on!

Aaaargh! Glad you changed your mind That's too good and complete as you say. As regards the fuel consumption, have you checked the air filter? If all 4 plugs are sooty, it must be something that affects all the cylinders. A manky or over-oiled filter does this. A good general service and clean/set up the carbs will help.

As TonyC says, later bikes have an ignition key type steering lock. Mine does. However OP's bike looks earlier so would have had a bottom yoke mounted one .........easily unscrewed, if it's not there.

Probably, but don't expect too much. Those calipers and discs aren't up to much by modern standards. Best to ride within its abilities. Be careful with upgrading...you might end up with something like mine! I started with GS1000 forks and brakes, and one thing led to another. I also took mine out for it's first blast the other evening. After riding my winter bike (BMW R65) for the last few months it felt like a rocket on rails! BTW, on my other GS, a standard 1000S, I made the brakes better by moving the lever/master cylinder inwards on the bars as far as they would go. They moved about 1/2" or so, just enough to alter where you pull the lever, so you get more mechanical advantage. Works ok, not sure if it's possible on the 750.

I would. You don't need heavy duty springs or anything else, you just need stock parts in reasonable condition. Try the scotchbrite thing as Gixer1460 mentioned, and check they're perfectly flat. Also, try and buy the parts second hand. I've bought complete clutches in the past for less than a set of steel plates new.

I changed the steel plates on mine and noticed a big improvement. I have a completely standard clutch, but all genuine parts, not pattern. No problems up to 115bhp.

If the wet test made no difference, no 2 is fooked. Either way, head off and investigate.