Red Dellorto Flatside 28bs
#1
Posted 19 May 2010 - 09:32 PM
#2
Posted 20 May 2010 - 02:18 AM
Sherco250cc, on May 19 2010, 04:32 PM, said:
I am not quite sure just how popular these things are becoming. Seems mainly the top lads running them.
As they still seem very similar to the stock carb, many of the same principals should apply. So what jets are you running? Where did you source it? Does the seller have recommendations? Possibly you just have a new carb with mfg slag that needs cleaning?
I think Splatshop sells them, might call, and if you are lucky, maybe MRS knows something they will tell.
Symptoms?
This post has been edited by copemech: 20 May 2010 - 04:05 AM
#3
Posted 20 May 2010 - 08:00 AM
The carb and top end package costs about $1800.
#4
Posted 20 May 2010 - 08:22 AM
#5
Posted 20 May 2010 - 08:37 PM
I got the carb off a scooter website based in germany mega cheap so thought id give it a shot,
it was the same as the dellorto VHST 28BS but red that was on splat shop,
but its probably jetted for a lambretta scooter and not a sherco haha they look mega trick!!!
I didnt know that paxau had moded them like wish id of known before,
With jets around the same as the standard it should be alot better was qhite surprised it felt alot smoother with it on but yet a slight power increase it ran fine for around 15 mins and then started to choke up, the same as what my keihn did when I tried it apart from this didnt just bork out.
Many thanks Tom
#6
Posted 20 May 2010 - 10:16 PM
#7
Posted 21 May 2010 - 03:50 AM
Gasgas tried the VHST several years back it seems, but went away from them, problems roumoured. They were selling them as a replacement for the troublesome Mikuni's on the Beta's with some reports that they worked well.
I cannot fathom why one would run ok initially then go downhill unless there was crap in it.????
I cannot fathom putting a 28 on a 250 either, as if you really need more power, why did you buy a 250 rather than a 290?
The Kiehin(or OKO) is still a better mixer, yet more finiky! Take your pick on the OKO- 24-26-28-30mm!
Long story made short, sounds as though I shall refrain from that experiment untill Paxau calls me with a solution and hell freezez over.
#8
Posted 21 May 2010 - 04:19 AM
Quote
My 2.5 Sherco Access did come stock with the 28mm VHST. I agree, I think that was a lot of the problem I was having with the carb.
I just put a 24mm OKO on my son's 2010 125 (with good results) so I then stuck the 26mm off the 125 on my 250 and all is well now
#9
Posted 22 May 2010 - 05:04 AM
sirhc, on May 20 2010, 11:19 PM, said:
I just put a 24mm OKO on my son's 2010 125 (with good results) so I then stuck the 26mm off the 125 on my 250 and all is well now
Oh, btw Chris, I think I just missed meeting you in OK? I seen Ty's bike and such on Sunday when I came up. Was BS' ing with the PA guys just behind there in the pits, yet did not see you if you were there?
MC
#10
Posted 23 May 2010 - 04:16 AM
#11
Posted 24 May 2010 - 04:30 PM
The Dell'Orto VHST is very sensitive to float level, much more than standard PHBL. The first batch of VHST carbs were prone to fail at the level-valve, then caused the bad reputation when the GGPro (280) appeared in 2003. After that, the factory re-designed the level-valve system and the carb worked well when properly jetted.
I have a unit of the first batch (actually designed for the Cota 315, when Dougie were riding it) and found a better stability when I increased the lenght of pilot jet, allowing to aspire gas 4 mm deeper in the vase (details in http://www.terra.es/...rlintec/taller/ )

I wonder if the new configuration of Sherco 2010, with a fuel-pump could affect adversely to the level again?
Cheers,
JM.

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