Vhst Carb For Beta

[dave]

I

[neonsurge]

I've been following this thread with interest since this is the first time I've heard of a Beta carb problem that hasn't been solved by applying all of the usual mods. My own '06 has carburated flawlessly right from day 1 and apart from having to unblock the pilot jet after every ride (although that may well be a consequence of the uncharacteristically hot and dusty weather at the moment), I've not experienced any of the classic Beta carb problems - no dribbling fuel, no "fluffiness" off the bottom - nothing.

This combined with the fact that as r2w mentioned, all of the factory boys use the Mukuni carb (albeit with the floatbowl extension) suggests to my mechanically inexperienced brain that maybe the problem isn't carb-related. Ignition maybe? Timing/CDI? I dunno.... after all the hassle you've had, I'd be tempted to drag it along to Lampkin's and get them to take a look.

[neonsurge]

Yes, the '06 is definitely "poppier" than previous models - very significantly so compared to my '03 (which should be running pretty clean following it's rebuild and a thorough exhaust de-gunking). The jets in the '06 carb are identical to previous years (150 main/30 pilot).

[stuessenhigh]

mmm...and I always thought the 03 was the most poppiest sounding one.

[carl ekblom]

I have to say it is a massive improvement over the mikuni

Yes, specially in low and midrange.

the only draw back that keeps re-occurring is the pilot jets are prone to blocking

Yes. Its more sensitive to dirt and dust.

I had some cold starting problems before but changing pilot jet from S37 to S38 and choke jet from 60 to 70 seems to have sorted it out. Now it usually starts from cold in 1st or 2nd kick.

Carl

[tilertrialler]

interesting read these pages, I own my first beta 250 ..06 brand new, and the carb has been a nightmare from day one. firstly leaked fuel, had mads done as surgested on internet pages, moved position of hole, stopped fuel leak ,but now will not start when facing down hill. you que up to start a section facing down hill and it just wont start i have to face the bike up hill then it starts its a joke, never had any probs with the gas gas.

phoned lampkins , now one has problems with there carbs, ha ,ha, , they do not do the hole mod now as they had the not starting problem , the fuel now floods the piolet jet. they said the float level has to be a set mesurement i have tryed there measurement did not work , am taking carb off after every trial and setting float level higher. again a joke.

where do you get these dellorto carbs?? ,does the bowl spacer work are you buying them from lampkin.

they new gas gas looks lovely, who talked me into a beta. all i want to do is start the bilke and ride it,

[the addict]

As you have read I have had a nightmare with my carb as well, flooding poor running etc etc from new. Very nearly sold the bike 2 weeks ago due to it. I have set the tangs at 4mm from level and dropped the needle one notch to lean the fuel. Standard pilot and main jet 30 and 150. Now using 100% optimax and 70ml of repsol in 5 litres. air screw is between 2 to 2 and a half turns out. Try those settings, and also running a bpr5es plug. Yer the top lads use Mikuni but I bet they are not the standard ones we all have to put up with, blueprinted more than likely and the best from the batch. Bike still p*****ng fuel out and have to switch the fuel off when stopped else it wont start. Can live with that for the time being as the bike is actually running well in the past 2 weeks although still pinking at flat out up hill.

The dellorto will need lots of setting up but I will change if I have any more problems from the Standard Beta junk

BVM Moto and Lampkins do the extra float bowl mod, think thay are about

Edited July 16, 2006 by Betarev3

[barrybaines]

As you have read I have had a nightmare with my carb as well, flooding poor running etc etc from new. Very nearly sold the bike 2 weeks ago due to it. I have set the tangs at 4mm from level and dropped the needle one notch to lean the fuel. Standard pilot and main jet 30 and 150. Now using 100% optimax and 70ml of repsol in 5 litres. air screw is between 2 to 2 and a half turns out. Try those settings, and also running a bpr5es plug. Yer the top lads use Mikuni but I bet they are not the standard ones we all have to put up with, blueprinted more than likely and the best from the batch. Bike still p*****ng fuel out and have to switch the fuel off when stopped else it wont start. Can live with that for the time being as the bike is actually running well in the past 2 weeks although still pinking at flat out up hill.

The dellorto will need lots of setting up but I will change if I have any more problems from the Standard Beta junk

BVM Moto and Lampkins do the extra float bowl mod, think thay are about

[the addict]

Cheers Barry,

Yer its a shame, had 4 Betas so far 01-03-04 and 06, all have been spot on especially the 04 but not this one. I work bl***y hard and my spare time is limited, last thing I want to do is to be pulling a new bike apart in the middle of a quarry when I should be riding it, can easily be doing that with a Gasser which rides better. Two of my mates have 06's and although not as bad as mine thay have had problems with carbs and general build quality. We're not stupid when it comes to spanner work either so this isnt a lack of maintenance or not sure what we're doing, popped a plug yesterday? not sure why but a new one got it running well again thankfully

[carl ekblom]

Carb outlet is machined down to 35mm with a new groove and inlet is machined down to 46.5mm for good fit into original rubber mounts. I will test the R9359 Beta Factory part in a few days time.

I use the Champion N7YCC plug. Never had any spark plug problems at all.

Carl

Edited July 17, 2006 by Carl Ekblom

[tilertrialler]

betrarev3 seems as we have had exactaly the same problems , absolute nightmare, I just want to keep the bike serviced and ride every sunday.

I have got my float set at 4mm and it still wont start facing down hill, i am going to try another 1mm this week. drilling the hole stops the fuel coming out the over flow but it now goes to the jet.

phoned lamkins again they say set at 3mm and exepct fuel leaking out what a load of crap I dont think thats right.

I would still like to know where to buy a dellorto, lamkins did not seem interested in selling me one they said they are a problem and i will always be adjusting it , is this true.

what about a 2mm spacer between the float bowl casing ,that would increase the amount of fuel in the bowl then you could adjust the tangs even lower to shut of the fuel level , anyone got any thoughts on this idea,

the problem is obviosly the angle of the carb.

[the addict]

Tiler, only way I can stop the carb flooding when switched off is to knock the fuel off and switch back on after restarting, bloody pain but its the only way. Have forgot to do so a few times and lucky it has nt run out half way up a step yet? but early days!!! My mate bought a new Mukuni after his ran like ****e and it was fine, I think the real problem is the tollerences between each carb is so great some are just cr5p, we have the cr5p ones. Only reason I have nt bought the Dellorto is the set up time, I really dont want to spend the next 2 months getting it jetted right to ride, I just want to ride. <mention of this company is not permitted on Trials Central> trials do the Beta Dellorto

[carl ekblom]

First impressions of the R9359 carb std jetting, throttle neddle in middle position:

This is after a very short (15 min) test run.

After first start up I had to remove the carb and carefully blow the jets and passages (once again) with clean compressed air.

It feels softer and not so strong compared with my R9354 carb. I feel that the mixture is slightly weak at small throttle openings.

lamkins did not seem interested in selling me one they said they are a problem and i will always be adjusting it , is this true.

Not true. If this was true the Beta 125

[sideup]

The v-force reeds are not generally available here but i have made contact with the importer who may be willing to supply the kits. I have had several emails from some friends in the USA who swear by the v-force reeds and just doing the mods on the Mikuni...

Mikuni is good enough for Bou... it'll do for me at the mo!!

I tried the V-force reeds and was at first really impressed with the instant snap off the bottom. However I have recently switched back to stock reeds as my riding ability does not match the quickness they give. Found they got me in trouble...well more than I normally get into.

A top rider may have a different opinion but I also noticed Bou's, Dabil's, Brown's, bike at the world round appeared to be running stock or at least not the V-force reeds as far as I could tell.

Edited July 18, 2006 by sideup

[hrc1]

I too tried v-force reed block & found it flatten the power & restricted it. It seems the reeds are just too stiff.This was on an 05 250. Maybe it works on the 270 only....

I've tried several reeds over the years and only found Boyesen to be any better than std stuff. (I have Boyesen on the Pampera) Trying to get these for the Rev 3, but UK supplies slow.

I have a VHST here, one of the first batch, & I must try this again, with the mods/jets suggested here (thanks, chaps). I see the original photo I took of the first VHST is still doing the rounds.