Used the VHST for a while now, great carb.

Had a few problems the other week during that wet bank holiday, and to cut a long stroy short, I bought some boyesens as I suspected my old reeds were probably on their last legs. Installed, I was very impressed.

Left jetting exactly same as before

main 110

pilot s37

fuel screw 1 and 1/4 turns out (roughly)

This seemed a bit sharp at bottom, so following boyesens recommendations I went with

main 109

pilot s38

fuel screw roughly 1 1/2

This seems a bit better....but I am wondering if anyone else has had any experience of re-jetting a vhst for use with boyesens?

bike is 250 '07 Beta

Dan, Ralph has a VHST but on a 270, he loves it, jetting works well with 110 and 37 but the carb must be kept nice and clean or you'll have running problems, the Boyesens work really well on the Beta and with the VHST. Ive never had to re jet after sticking in Boyesens although they do say it might be needed.

Edited June 6, 200818 yr by The Addict

I suppose the 270 would need the slightly bigger main, my plug was a little dark when I pulled it after using a 110, so I stuck a 109 in.

Don't suppose you could ask Ralph how many turns out his fuel screw is? I lost my position but gone 1 1/2 for the moment. Think I have needle in 4th from top -this sound correct?

thanks

Dan, Ralphs bike is in my workshop at the moment so I will have a look for you tomorrow, not much point in asking him direct he would just say "What the F***s a fuel screw"

Edited June 6, 200818 yr by The Addict

hi cleaned ralphs carb for him again a couple of weeks ago and the fuel screw is set at 4 turns out hope this helps. found that any less than 4 to 4 an a half turns out makes it detonate when hot and runs to weak

Dad, you do more maintenance on Ralphs bike than he does his bike is under some considerable load with him on it so getting the carburation right is essential

yea i did notice that the bike really struggled to pull his athletic frame around so first plan was to get as much fuel into the engine as possible but we are now working on the 2nd plan due to the success of his ginster sponsorship we now have a 490 maico engine fitted. now if i can just get him away from the dinner table we can test and report !!!!!!!

yea i did notice that the bike really struggled to pull his athletic frame around so first plan was to get as much fuel into the engine as possible but we are now working on the 2nd plan due to the success of his ginster sponsorship we now have a 490 maico engine fitted. now if i can just get him away from the dinner table we can test and report !!!!!!!

Third plan to include the new 700cc Maico?! 80bhp!

4 turns out seems alot. I don't suppose you noted what clip needle was on?

sorry didnt check needle position just cleaned jets etc out while ralph was at the burger wagon. try 4 turns out think you will find it ok the plug colour was good to. used same carb on 315 mont also set 4 turns out