M750 carb balancing help please.

[Brian.]

Well, I finally managed to balance my carbs.

I was going to try Mr Gazza's suggestion of putting some plastic tube over the screw to help me aim the screwdriver but I couldn't get to it without removing the airbox & all that goes with it, so decide to have another go at it before I went down that route.

As I said previously, in my particular M750, a 1998, I could not get to see the balancing screw other than by using a mirror. This was because mine has oil heated carbs with pipes that have virtually no "give" in them at all, so I couldn't move the oil cooler out of the way and because of this I could not get into a position where I could actually directly see the screw.

It was a bit of a faff but it's done now.

Just a brake service, clutch fluid change etc, and a few other odds & ends, and I plan to tax it again from 1st March

Thank you to all who offered help & advice, it was all gratefully received.

Brian.

[motomartin11]

That's good to hear.Mine's still awaiting re-finishing of the tank paint following welding repair of the leak. Should be ready to go once that's done-hopefully by 1st April. Carbs have been stripped, cleaned and balanced so many times now it's untrue. I had a fiddle getting to the drain screws on the float bowls as I didn't want the carbs gummed up again if there's a further delay in getting my bike back on the road.

[Mr Gazza]

I didn't actually suggest pushing plastic tube over the screw. That sounds more fiddly than finding the screw with a screwdriver.

Maybe I should have taken more trouble to explain.
The tube could be metal, cardboard or paper. In true Blue Peter style, you can make a tube from paper and Sellotape, (sticky backed plastic.) in any diameter by rolling it round something, say, a pencil, or screwdriver maybe?

The idea is to make it a bit shorter than the screwdriver shaft and slide it over.
Then place the screwdriver on the screw by whatever means it takes and hold it there.
Next, hot glue whatever shaped bits of cardboard or whatever, to the tube and whatever comes close enough to stick to.
If it's rigid enough and big enough for the blade to pass through it should now be possible to slide the screwdriver in and out with care and find the screw every time by feel without having to see it. Just a guide really, I've no idea if it would work.

The principle is much the same as Adolf Galland's peashooter gunsight, which was very effective indeed for someone who failed the Luftwaffe eyesight test. (He memorized the eyechart to get to fly!)

[Darren69]

In the end I thought I'd take my own advice and bought one of these, more out of curiosity and it works surprisingly well with my android phone.
https://www.ebay.co.uk/itm/304758853...mis&media=COPY

I dropped a battery terminal screw and it dropped somewhere in the bike so maybe I can find it without pulling the bike apart?

[slob]

i always favour fishing with a (telescopic) magnet (pickup tool) for dropped screws, although it can be a little trickier surrounded by all that ferrous metal.

[Darren69]

That comes with a little magnet and a hook attachment which I didn't know. I have telescopic magnet tool but I cant even seen the screw to fish it out.. It went dink, dink, silent so I figure its on the engine case somewhere hiding

[slob]

exactly, i’d just poke the magnet down there s few times and see what comes up.

[Mr Gazza]

Aren't battery terminal bolts brass?
Many people don't realise that tyres are magnetic. Screws, little washers and other jetsam like to hide under the tyres in the dark, so you don't find them until you move the bike.

[Brian.]

Originally Posted by Mr Gazza

I didn't actually suggest pushing plastic tube over the screw.

Sorry Mr Gazza - I very definitely misquoted you there! I think I chewed it over for a while and it morphed into slipping something like a piece of battery breather pipe over the screw. Which as you rightly say would be even more fiddly! My apologies.

[jerry]

I spent some tome investigating possibility of extending the screw for balancing to 75mm soit would be easy to locate but found it was not really a viable idea

[Islander]

Originally Posted by jerry

I spent some tome investigating possibility of extending the screw for balancing to 75mm soit would be easy to locate but found it was not really a viable idea

I've been toying with the idea of making something similar to the idle adjustment extension to fit the balance screw.

I reckon a bit of bowden cable or similar, some adhesive lined heatshrink, a knob scavenged from somewhere and a home made bracket might work. Having spent the best part of an hour under my partner's M750 trying to access the screw it's motivated me to find a permanent solution.

What do you reckon?

Oh and sorry for the thread revival!

[Brian.]

Originally Posted by Islander

Oh and sorry for the thread revival!

Please feel free to revive it, it's something that certainly could benefit from being made easier! As I've said previously, on mine it's next to impossible to access because when I try to move the oil cooler out of the way it'll hardly move at all because of the rigidity of the pipework going to & from the oil heated float chambers on my bike.

If it was possible to drop the oil cooler it'd be a doddle.

Balancing just two carbs should be the easiest job to do, but because of access it certainly isn't, so any improvement is a plus.

Brian.

[Dukedesmo]

Originally Posted by Islander

I've been toying with the idea of making something similar to the idle adjustment extension to fit the balance screw.

I reckon a bit of bowden cable or similar, some adhesive lined heatshrink, a knob scavenged from somewhere and a home made bracket might work. Having spent the best part of an hour under my partner's M750 trying to access the screw it's motivated me to find a permanent solution.

What do you reckon?

Oh and sorry for the thread revival!

That's how the idle adjustment is on my Keihin FCR carbs, a small plastic knob hangs out (Ooer Mrs!) of each side of the bike and it makes idle adjustment simple even whilst on the bike.

Obviously with split-single carbs it'll upset the balance unless you adjust both by the same amount but the idea is great.

You can see said RH side knob in this pic, resting on the belt guard;

[900Rebuilder]

Best part of flatslide carbs is that they are designed to be tuned and worked on when compared to the stock CV carbs.

I'm sure that I've seen MX carbs where you can buy extended adjuster screws and I wonder if these may fit?

Finally when I can afford to buy another 900 for my partner I'm going to get one for her with fuel injection

[Islander]

Originally Posted by Dukedesmo

That's how the idle adjustment is on my Keihin FCR carbs, a small plastic knob hangs out (Ooer Mrs!) of each side of the bike and it makes idle adjustment simple even whilst on the bike.

Obviously with split-single carbs it'll upset the balance unless you adjust both by the same amount but the idea is great.

You can see said RH side knob in this pic, resting on the belt guard;

That's where I got the idea of using a flexible extension from. Both the M750 and my M900 have idle adjusters like that. I just need to get the necessary bits and some time. I'm confident that it'll work just fine and I'm lucky enough to have a spare pair of carbs to experiment with.