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New Rev 3 Mikuni Carb?

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Lads, Me and Ralph have just been looking at the Dellorto in the workshop, quite a work of art compared to the Mikuni. 110 main and 37 pilot and the float bowl looks much larger than the Mukuni even with the extension.

Ralph will be test running it Saturday afternoon and a full day up the dishes Sunday, sure he will give his verdict sunday evening. Apparently it gives much better and stronger bottom end power than the Mukuni and does'nt leak :hyper: If its ***** see Mondays TC ads page :D

Hi Gents,

Which Dellorto can be fitted to a Beta 250 (2002)?

Best of balance.

Neo

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  • AJ, not got an 07 (06) so cant say much more, look great bikes though hope you enjoy it. Well worth buying and getting the dealer to fit the float extension bowl as well, should cure pinking on climbs

  • Just thought I would add my 10p worth to this thread. Bought my 06 250 new and have had no problems at all. No fuel leaking, no downhill starting problems noticed and no loose bolts from new. Before

  • Been meaning to take some pictures of the Mikuni carb mods as there is always questions about it one here, hope they will help someday The pictures are of my carb with mods carried out by BVM earlier

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Neo, the one Ralph has got, you can get one from Lampkins, Dellorto have put the choke etc on the right hand side for the Beta :thumbup: Ralphs VHST is still running perfectly since he bought it in November, thats at least 4 hours riding :angry:

I've been thinking about this, what would happen if I just blocked the pipe that the fuel leaks from up? Would it flood the engine?

Boofont, I expect the bike will flood pretty quickly but not 100% on that. Before Ralph got the Dellorto he fitted a long overflow pipe to the carb, it went under the float bowl up behind the carb and looped it back down near the swing arm. He just used a coulple of small cable ties to keep it in place, probably 12-14 inches of pipe to do the job. Sure he said it did nt seem to leak it out anymore. Have you adjusted the tangs on the carb yet?

Have you adjusted the tangs on the carb yet?

Yes, still spills out. Carb has been sent to JLI's for drilling.

  • 3 weeks later...

Neo, the one Ralph has got, you can get one from Lampkins, Dellorto have put the choke etc on the right hand side for the Beta :icon_salut: Ralphs VHST is still running perfectly since he bought it in November, thats at least 4 hours riding :thumbup:

[/quote

so what kind of charicteristics change with the new carb? has it been totaly reliable? and how was it to tune in initialy? (I guess i should be asking ralph)

Powellriver, The carb needed no rejetting or adjustments at all from stock, Ralph has been a little slack with cleaning it every ride but the carb has not missed a beat once since he bought it. Its been used in streams, deep mud and dusty conditions and no problems at all, if I had the spare cash I would buy one tomorrow.

The main changes to the bike are:

Extremely smooth throttle/rev range all the way through

No leaking of petrol

Bike starts pointing downhill

Lots of low end grunt and torque

I have had a go on Ralphs bike and can honestly say it is the nicest bike I have ever ridden, and I have been on a few over the years

There is a Delorto VHST 26 off a Beta on Ebay for sale if anyone is interested, I would like to add this sale is nothing to do with me or anyone i know i just thought it may be of use to someone, item no (280096904259)

  • 5 months later...

I have made the Billy T modifications, so the tang level is correct now. It's way better, but sometimes on decline, the engine still stalls, and the bike can't be started facing downwards.

Should I make the drill modifications? Will that solve the problem? Or the drilling method only solves the fuel leaking problem, and has nothing to do with the engine stalling on decline?

The drilling mod wont make a p*** bit of difference to it not starting on anything but level ground, the bike sounds like its loading up on the downhill sections, not sure how to cure that if the float height is set correctly already. But on the bright side these bikes are the last with Mukuni on them so no more starting probs and fuel p****** everywhere come October :blink:

Do the drilling mods to carb it sorted my fuel leak problem and stalling down hill problems straight away!

  • 2 weeks later...

I made the drilling mods, too. The fuel leaking problem solved. But I don't see any differnce about the engine stalling downhill. So, I've set the fuel tangs a bit even higher, and I think that now it's ok. Still not perfect, in some really steep downhills the idle speed still decreases, but most of the time it doesn't stall.

I saw a picture here about a float extension bowl and a main jet shroud. From where can I order theese, and how much do they cost? And are they making the carb absolutely perfect?

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