Why Does Rob's R65 Run Rough?

[SteveD]

Does anyone know what, exactly the suffix means?

My carbs are 64/32/203 & 204 (from a '79)
flat tops type 64-2. slide 911-24, main jet 140, needle jet 2.66, clip position 2

For '81-'84 they were 64/32/335 & 336
r65ls type 64.3, slide 907-1, main jet 138, needle jet 2.64, clip pos. 3

For the mono-shock R65's they were 64/32/361 & 362.
64.3, 907-1, 130, 2.66, 3

ref: The BING manual.

[Deleted User 287]

Thank you, Steve.

It would appear I need slightly smaller main and needle jets, and to move the needle position one spot.

IIRC, the needles have 5 clip positions? In which case, position 3 is easy - it is the center.

Does a smaller jet size # indicate a larger opening, or a smaller?

[ME 109]

When you put the needles in the slide, make sure the first notch is parallel with the little clip in the slide or you could go right past the first notch and into the second without realising it.

[Deleted User 287]

I've never touched needle position before. I seem to remember hearing one turns them to set them free, and then turns them back when the desired position is achieved?

It looks like one spreads the two halves of the spring apart to move the needle?
Any suggestions on a tool?

This is from an old picture of my left carb:

[ME 109]

Turning the needle 90 degrees (held tightly between the thumb and forefinger) will disengage the notch from the spring clip. pushing or pulling the needle after rotating 90 degrees will allow the needle to slip into the next notch etc.
Make sure both needles are in the same position.
Rob, your slides look different to mine in that the spring clips are clearly visible, so it should be easy to see what position (notch) the needles are in.

[Deleted User 287]

Hi guys! Long time no see!

I have brand new OEM headers on the bike, and I am waiting for my pattern crossover to arrive from Motobins.
I got to thinking about how I did NOT want my brand new pipes to turn too blue from bad jetting, so I have been re-reading this thread.

I replaced the rubber carb to head connections last weekend. I am pretty sure I was still running the originals.

I took Timo's advice and ordered rebuild kits from Eubmw just to get a new set of diaphragms in there.

No Duane, I am not going to rebuild the carbs, but I do want to get them as close to set up for these '81 heads as possible before starting it for the first time.
So tomorrow I am going to call Bing and order 138 mains and 2.64 needle jets as well as their manual.

I am also going to change the needle position from #2 to #3 as pointed out by SteveD.

Along with a properly sealed exhaust system, I anticipate smoother tuning this time around.

Wish me luck and good gas!

edit - And I will ask the folks at Bing Agency if I need to worry about the different slide numbers that SteveD noted from the manual. That might be merely the result of flat-top vs. dome-top.

[Rev Light]

I spent years messing round with an after market set of stainless headers before junking them for an old set of rusty originals that I painted black. I have never looked back. Bad fitting exhausts are a pain.

I have also sucked up the fluid of my home made manometer into my R100. The manometer was set up for my R65, and I plugged my poorly tuned R100 to it when I first got it and before you know it all the fluid is racing towards the carb! Panic!

But it just goes to show, that:

a. The R65 was in pretty good shape as it never did this
b. The R100 has a bigger set of lungs, so to make the manometer work I had to use a more viscous fluid.

I would take a close look at you carbs, I was chipping away what can only be descibed as limescale out of the inside of mine (inside where the main jet is) before I got them all working again. And it took more than one attempt.

Cheers