New slow jets work wonders!

[andy_c101]

Today I fitted my new ("042 size, press in type) slow jets to my 550k3 & it has given 'Ceebee' a new lease of life.

Tickover is so silky showroom smooth now.

I should have done it years ago (instead of all that carb cleaner, solvent soaking, ultra-sonic cleaning)
I bought the jets from Sirius Consolidated Inc Canada (I got stung by UK Customs for VAT, but now I dont care)

I also reset all the carb float heights to spot-on 14.5mm, as measured at opposite end to the pivot (previously they were way out at 17mm!). My carbs are the Keihin 'PD'-type with brick-shaped floats.

I just reset the air pilot screw to 1&half turns out while carbs were apart.

Fitted the carbs back on (did it within an hour; warmed the air intake rubbers and lubed with WD40, then "massaged them into place"; I find a smooth-end screwdriver blade helps)
-then at first attempt with half choke she fired up and ticked over at 1500rpm, then after a minute of so pushed choke in, and sat there ticking over at 1100rpm!

- I used to have to juggle throttle and choke, with revs going up-n-down like a yoyo, till it warmed up.

On my testride I also found that she pulls much much better from mid revs; I think that float height might have made the fuelling a little lean(?)

So if anyone out there has ever had problem with uneven tickover, new slow jets is your answer!

A few images attached.

[basketcase]

Hi andy_c101,
I`ve just bought a rebuild kit from a company in Japan, £31 all in!! It`s my next job. Like you I`ve tried all the other options and it still runs like a 3 legged pig!! Revs anywhere between stalling and 4,000....and that`s just at tick over. I`m not too sure about how to set the float height but I`ve got the Clymer manual so, when I find it out, I`ll have a read. I`m half way through a home renovation and the bike is buried in the garage. At least the battery is fully charged now, I can`t wait to dig the bike out and try to start it, it hasn`t run since september last year. And YES, I did remember to empty the float bowls, little use as the carbs are knackered anyway!!Cheers for the encouraging info, it sort of kick starts me into doing something when I read the tales on here!

[Bryanj]

DON'T believe the Clymer if its a K3, set to 14.5mm

[z1100r]

These 4's are incredibly sensitive to carburation - if you seek perfection. Its very difficult to get it spot on. The airbox doesn't help with its inconsistent restrictive shape, but when its all working well they really are so much smoother and nicer to ride. If I could think of a setup that would look cool I would fit a single carb I think and get rid of all the headache you get from 4 carbs.

Glad yours is now OK andy

[andy_c101]

Yeah, I'm really pleased with the carbs now.
& what great weather over the weekend too; I was able to have some great runs around the lanes!

- just a slight squealing front disc to sort out (again!).
- any tips on that?

Andy C

[LesterPiglet]

Try some copper grease behind the pads. I drilled my disc to see if that helps but haven't tested it yet.

[andy_c101]

Les,
Yes, I have got copper grease behind the pads (& the nylon washer).

I'll be interested to hear how you get on with drilled disks.

At the last attempt, I also 'emery clothed' the pad faces to rougth them up; it worked for a day or so but the squeal returned.
I'm wondering if it could be the caliper mounting arm; despite adjusting the clearance, no change. I plan to take the arm off and copper grease the finge pin of the caliper arm.

- I read some where, saying Honda pads can solve it; can you still get those?
I think these pads are Kyoto.

Andy

[LesterPiglet]

Yes, I have got copper grease behind the pads (& the nylon washer).

Which side does the washer go in? I took mine apart to paint and can't remember.   

[andy_c101]

Nylon Washer definitely went on the moving piston/pad.
- see my kit  just prior to rebuild; the washer placed on the new piston

[LesterPiglet]

That's all very pretty.    Thanks.

[florence]

The front brake on these bikes will squeak and I think it is something you have to live with.  Mine squeaks under heavy braking and usually stops squeaking when it needs adjusting.  It always works better when it is squeaking. 

Applying a bit of physics, in order to acheive a reduction in kinetic energy the brake, by applying friction to the disk, turns that energy into heat, light(if the disk gets red hot) and sound.  In the seventies, Honda brakes were so bad they needed to make a sound to inform the rider that something was happening.   

[Bryanj]

Now Now Florence, remember in the 70's that Triumph had a twin leading shoe conical hub brick and norton had a lockheed sieze up, neither of which worked for long if at all so Honda's disc was a revelation, except in the wet---but then who want's a locked up wheel in the wet anyway

[florence]

You are right Bryan, I was only joking, the British one's were much worse. 

In all seriousness the CB500/4 brake I have is actually really good for what it is.  There is somewhat a lack of feel which adds to the perception that they don't work well, but,  when I conducted a stopping distance test on a quiet road, in the dry, from 60MPH, I was very surprised how good it actually was.  The only brakes on a bike I've ridden which were better were the ones on my CX500 which were phenomenal.  As that is the newest bike I've owned (1979 model) I am not really qualified to comment authorititively.

Steve

[Bryanj]

Years back i twin disced my 500and was going to Skellerns in Worcester (theres ablast from the past)to collect some urgent parts when a dear old lady (said through gritted teeth) stepped off the kerb about 10ft in front of me into the big puddle caused by the torrential rain----hence why i said who needs a brake that works in the wet............... I added handlebars, headlamp brackets and headlamp shell to the parts order!!

[andy_c101]

( i must apologise for changing this diverting this thread to brakes.

Just to update, I (think) I have got rid of my brake squeal.
I split the calipers, gave a small sqirt of brake cleaner spray around piston/caliper; & notice some early signs of rusting around the outer diameter of the brake pad backplates; so I emery'd that away, and applied a fine film of copper grease.
- scared silly about any of it contaminating pad material or discs.
 but it seems to have cured the squeal..... for now at least!

 & to top it all, today she passed the MOT, Yessss!! & not even a single advisory.

happy bunny!