Jet size for the UK?

[Snod Blatter]

Hi all, I have the bike in bits for valve clearances (again..) and would like to use the opportunity to replace the 136 (!) mains it currently has with something more suitable. I didn't put them there, a silly tuning place used them to try and counteract the worn emulsion tubes..

So what do you recommend for the UK climate? 142s? I replaced the emulsion tubes around 2500 miles ago so wear should be negligible on that front, so shouldn't need to be much smaller than stock. Also I didn't replace the needles, they looked perfect to me - do they really wear oval? I couldn't even see any marks on them but they've done something like 12-15K miles.

Finally, the silly tuning place (paid for by a previous owner I'll have you know!) moved the clip to the top of the needle, again to try and combat the strange richness they were finding. What is the original position for the clip?

Before anyone says, I have tried searching but there are so many pages of guff I just can't be bothered Oh and the air filter is K&N if that makes any difference at all with the stock airbox.

Thanks!

[cobbadiggabuddyblooo]

Do yourself a favour and replace the needles too as you'll only start basing your tail a little down the track again.
Get some 140 mains and needle in the centre position. You should be good for another 7,000 miles then drop your needle down further and you'll get another 10,000 miles before you get another carby kit and do it all over again.

[Snod Blatter]

Thanks cobba!

If anyone out there is running 140s how does it deal with crosswinds? With the 136s riding in crosswinds is horrendous, the extra air getting into the airbox leans it out to the point where it barely runs.

[Con Rod]

I run 137.5 here and have nver had an issue, hotter climate obviously but even in the tablelands in winter, where we get close less than 10degrees c no issues

I expect 140s would be plenty rich

[Snod Blatter]

And thank you Con Rod.

It is possibly that mine was so badly affected by winds because of the needle being so low, but even wide open 136 doesn't seem to be enough, it lacks the grunt it had when it was rich.

I shall get 140s and new needles, thanks all.

[Snod Blatter]

A little update, now I've been running 140s and new needles for a couple of weeks.

They seem fine, the fuelling seems nice, and it takes choke to start and then I can knock it off straight away which is very different from the 136s where it had to be nursed up to temperature. It only slightly fades away in crosswinds, this is loads better than the 136s. Running along at speed the temperature gauge reads 70C almost all the time, which is acceptable but much hotter than it was when I bought it where the needle would barely get off its stop.

However! In UK traffic I think this is still too lean. I left a dual carriageway and there were maybe 15 cars in front joining the road ahead, which itself was heavily congested - it didn't lend itself to being filtered through. By the time I got to the top of the slip road (this maybe took 3 minutes) the temperature gauge was nudging 100C and I was wondering if I was going to have to abandon it on the side of the road to let it cool down. I daren't take it into a town anywhere, it'll boil itself. Of course as soon as I get moving again the temperature falls down rapidly. I'm okay with this for now and feel safe in the knowledge it will get richer, but if you live in the UK I'd recommend 142s or maybe even 144s just to keep the temperature down. You never know when you might get stuck in traffic!