Jump to content

Sherpa Advice Please.


netley
 Share

Recommended Posts

Hi, I've just bought a 1977 Sherpa 350 with a mikuni carb. I've cleaned it thoroughly as it was leaking from the overflow pipe. Does anyone know the float height setting? I have it running but not easy to start and it dies like it's out of fuel after just a short run but starts again after. The air screw is only about 3/4 turn out and I've seen elsewhere it should be 2 turns out. Can anyone confirm this?

Cheers

Neil

  • Like 1
Link to comment
Share on other sites

 

Hi Netley welcome to the tc forum.

Probably best to strip the carb and clean with compressed air, check the condition of the float sometimes they can split if they are the hollow type, clean air filter, check ignition timing, check wiring contacts maybe a condenser as well then fit a new plug and try again.

On the Beta section there is info on Mikuni settings, best place for Mikuni spares if required is Motocarb.

Good luck

Edited by trialsrfun
  • Like 3
Link to comment
Share on other sites

 

Hi

 

My 199A runs quite well with the following jetting (26mm VM carb): Needle 5C23, throttle 2,  main jet 140, idle jet  30, needle jet O3, needle first groove from top. The problems with dribbling VM carbs are well known (see Beta forum). This is why I´m now testing a Dellorto PHBL.

/Carl

  • Like 2
Link to comment
Share on other sites

 

Welcome to the forum netley.

Here is a very well laid out fix you can read through http://www.motomerlin.co.uk/moto/betacarb.pdf

I also came across the following article as well, "Is your BETA drooling fuel? By Clark Pittman" on a Club newsletter from the States http://www.ntxtrials.com/web_newsletters/RCR0106.pdf scroll down to the 2nd page.

Hopefully this might sort your carb.

Edited by model80
  • Like 1
Link to comment
Share on other sites

 

Neil, my 340 runs with air screw at 1 1/2 turns out with a 35 pilot jet. Runs very well on the vm26. Also had a 250 on one, also very nice runner. Both needed a good flood for cold start (lean bike over) but 1st kick when warm.

Just fitted an OKO to a Montesa 348 and very impressed, if you don't percevier with the mikuni, an OKO might be a good option - eBay for about £65. Don't be tempted with the cheap ones which are likely copies.

  • Like 2
Link to comment
Share on other sites

 

Hi

 

My 199A runs quite well with the following jetting (26mm VM carb): Needle 5C23, throttle 2,  main jet 140, idle jet  30, needle jet O3, needle first groove from top. The problems with dribbling VM carbs are well known (see Beta forum). This is why I´m now testing a Dellorto PHBL.

/Carl

 

have you got dellorto settings at all yet?

  • Like 1
Link to comment
Share on other sites

 
 

Thanks people, Really appreciate the help. I've now had it running but there is still some fuel overflowing but I won't have time to reset the float height until next week.

Cheers.

Neilpost-21331-0-71586400-1468143128_thumb.jpg

  • Like 3
Link to comment
Share on other sites

 

This is the jetting for PHBL 26mm that I´m currently using:

Pilot 30

Needle jet K266

Needle D56 4th groove

Main 105

Throttle valve 60

 

Low and mid throttle is as good as it was with the Mikuni but I get some more revs from tne engine at top end and it feels sharper overall and there is no dribbling.

Both the Mikuni and Dellorto are way better than the original Bing

Adaptors for both carb inlet and outlet  must be made.

Do I have to say that I stay with the Dellorto ;)

post-1039-0-99621300-1468511237_thumb.jpg

Edited by carl ekblom
  • Like 5
Link to comment
Share on other sites

 

Hi, Thanks for all the replies. I wondered if anyone could identify this carb?

That way I can make sure I have the correct settings and float height. I'll be adding the air filter Tuesday.

Cheers

post-21331-0-36987000-1468763858_thumb.jpg

Link to comment
Share on other sites

 
 
 
 
 

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
  • Create New...