what jets are best to run in a set of zzr1100 carbs mounted to a black top 1.8 zetec engine?
i was thinking 180 (1.8mm) i dont really care about fuel economy or anything i want speed and acceleration lol
i know bigger jets give better acceleration but you can over jet carbs and ruin your performance.
what jets do people run on there carbs?

Thanks

Yeah of course you can over jet. Instead of having a nice mix for WOT, you end up spewing far too much fuel in there It runs massively rich and soots up your exhaust, engine and fouls your spark plugs.

yes i know what over jetting means and does but im just curious what size jets other people are using on there 40mm carvs on 1.8 zetecs.

if not ill just bang 180's in it and try that

If you want the best power out of your engine the correct way is to get it set up by a rolling road. But there is more to performance than outright top end power. What percentage of the time do you spend at WOT at max revs, in reality 0% of bugger all. What you want is a good spread of power across the whole rev band and what is just as important is instant pick up when you need to floor it. Over jetting will ensure you have neither of these plus the excess fuel will simply wash the oil off the bores and wreck the engine.

Once sorted it will not need doing again and you will always know you are getting the best out of what you have paid for and spent time fitting.

We ran significantly smaller than 180, but its a trial and error process - certainly bigger is not necessarily better. No two set ups are identical and will need adjustment accordingly.

Really, as a minimum you'll need a Lambda gauge to see what your AFR is like through the rev range, then adjust your jet sizes and needles accordingly.

Obviously a rolling road is the best option, but to get you moving, make sure you aren't running too lean, this can cause a lot of damage.

just noticed you're down the road - I work in NR14.

Happy to offer any help if you need it.

Thanks mate will give you a shout if I need any help, I have access to a rolling road and I can map ECUs and stuff as I work for a lotus race team and we are currently having bespoke throttle bodies built, I build performance engines weekly but I have never used bike carbs before.

I would think 1.6mm is more like the right size - I run this size in my zx6 carbs on a 2.0 zetec. maybe start at 1.5mm and see what the afr is like. Are the needles adjustable on zzr1100 carbs?

Stu