betarick Posted February 12, 2007 Report Share Posted February 12, 2007 I have been reading that people have been moving needle up or down a notch what difference does this make! and were should it be set. I have done carb drilling mods and float bowl extension and changed jets to 27.5 pilot and main 145! Quote Link to comment Share on other sites More sharing options...
the addict Posted February 12, 2007 Report Share Posted February 12, 2007 (edited) Moving the circlip further up the the needle (dropping the needle) will weaken the fuel flow and richen it the other way. The standard setting is in the middle, most people weaken the mix by one notch. You may not have to move it though as you are already running weaker jets. Edited February 12, 2007 by Betarev3 Quote Link to comment Share on other sites More sharing options...
mil Posted February 13, 2007 Report Share Posted February 13, 2007 I've never fiddles with the inside of the carb save for cleaning it and adjusting the 'tangs'. Went about trying to adjust needle height and isn;t clear to me how to do this. If you flip the carb over (from orientation on bike) and take off the chamber by undoing the four screws, you see 2 'towers' in the centre: the taller of which has a brass coloured 6mm nut on top (idle jet??) To the left of this is the brass forked 'tang' resting on a small spring, which in turn is on a larger 10mm brass coloured nut (main jet??). Can anyone guide me to what I do next?! Please forgive my virgin uselessness with regard to this. Mil Quote Link to comment Share on other sites More sharing options...
the addict Posted February 13, 2007 Report Share Posted February 13, 2007 (edited) Mil, hope the pic helps, not gone into huge detail but all the main parts are shown. I usually remove the main jet (6mm) pilot jet (deep in the hole shown) tangs,tang pin and fuel regulator needle. Spray plenty of Carb cleaner through the passages and in the removed parts (Oposite direction to fuel flow if possible) and give the whole lot a good blast through with the air line. Be carefull removing the pilot jet, it needs a small thin flat head screwdriver and dont overtighten anything when putting it together again. One tip if you are unsure which way the tangs go back in,(up or down) there should be a small "A" stamped on them, the A goes up so you see it when assembled. I do this every ride to be sure everything is clean, bit excessive but I can do it in ten mintues now and good to know its clean and running right for the next ride. The needle jet has a very small circlip usually in the middle notch as standard. The circlip can be removed easily with pliers and even easier to loose it in the shed though, be carefull. It is easier to put the spring etc back in place with the cable disconnected from the throttle body if you are planning on moving the circlip height. Remember if you remove the slide/spring/cable etc that the thin round plate that sits in the slide goes on once the cable is fitted and not before. The hole in the middle of it is for the needle not the cable, put the needle into the slide hole, put the cable through the spring first, fit the cable to the slide ensuring it slots/locks into the second hole. Then put the plate on top of the needle making sure the raised notch locks into the cable holes and is lying perfectly flat. You have to do all this whilst holding the spring compressed as you will find when doing it, can be abit tricky but easier with the throttle end of the cable disconnected. Edited February 13, 2007 by Betarev3 Quote Link to comment Share on other sites More sharing options...
mil Posted February 13, 2007 Report Share Posted February 13, 2007 Thanks for the info and photo Betarev3. So I don;t need to adjust these jets, just clean them out. It's the needle in the top assembly attached to the throttle cable I am adjusting? I'm suprised you clean out your carb and jets after every ride. I haven't taken my apart for a month and it was all cystal clear and clean inside! Thanks Mil Quote Link to comment Share on other sites More sharing options...
the addict Posted February 13, 2007 Report Share Posted February 13, 2007 Mil, I clean the carb out mainly incase its got water in it from the Jet wash etc as well as dirt. I enjoy the maintenance side of having bikes so no problem doing it. Carbs may look clean but somethings you cant see will block them up sometimes. Is your bike running too rich then? is that why you want to move the circlip? if you do move it keep an eye on the plug to make sure it isnt running too weak or you could try the Jet kit so you can play with both Pilot and main Jet settings. Quote Link to comment Share on other sites More sharing options...
seandellear Posted February 13, 2007 Report Share Posted February 13, 2007 That is the first time I have seen inside a mikuni (dellorto on gasser myself). Is it me or do they seem very crude/simple compared to the dellorto? Quote Link to comment Share on other sites More sharing options...
the addict Posted February 13, 2007 Report Share Posted February 13, 2007 Your not wrong Sean, think the first patent was taken out in 1845, been p*****g fuel out ever since Quote Link to comment Share on other sites More sharing options...
essex rider Posted February 14, 2007 Report Share Posted February 14, 2007 Your not wrong Sean, think the first patent was taken out in 1845, been p*****g fuel out ever since Identical to the one on the beamish (well very similar anyway) and that doesnt pee fuel over the floor, the stator has lasted 30 years and there isnt a thermostat to go wrong.............beta owners, just buy a beamish Quote Link to comment Share on other sites More sharing options...
seandellear Posted February 14, 2007 Report Share Posted February 14, 2007 Your not wrong Sean, think the first patent was taken out in 1845, been p*****g fuel out ever since Quote Link to comment Share on other sites More sharing options...
betarick Posted February 14, 2007 Author Report Share Posted February 14, 2007 As i have done all carb mods i was just wondering were everyone as set there needle to and also were there air screw is set to as mine is set to 1 1/4 turns out! Quote Link to comment Share on other sites More sharing options...
the addict Posted February 14, 2007 Report Share Posted February 14, 2007 Pretty sure most riders drop the needle one notch only to make the mix leaner, that does nt mean you have to if your bike is running ok though. If its bogging low down and needs throttle clearing it may be worth a go, not sure what my air screw is set at as it gets moved quite alot from day to day. Most Betas are too rich from new and need leaning but some are'nt? Quote Link to comment Share on other sites More sharing options...
betarick Posted February 14, 2007 Author Report Share Posted February 14, 2007 Bike seems to run right and i dont after clear throttle just noticed on sunday on a long hill climb it seemed to bog down and die and took a few kicks to get it going! I then removed spark plug and it was a nice brown colour so i guess air srew is right! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.