21 replies to this topic

[Old trials fanatic]

Thanks for the clarification Javier. Hmm handicaps? must admit i hadnt thought of that one before. Will wait and see how it pans out but an interresting concept. It's a bit easier for you guys to impliment as you have scrutineering and a parc ferme, well you did when i rode at Robregordo, so easy to keep an eye on things plus theres nobody more knowledgeable about Trials bike specs than the Spanish. Keep us posted on how it all works out

[Woody]

Big John, on 29 January 2012 - 05:50 PM, said:

Hi Woody,

Is that the one that is for the Montesa 348 with Amal Mk2 Concentric?

I have measured the Mikuni VM26 it is 34mm inlet; the PHBH28BS is 36mm and the Bing a whopping 40mm.

I know we have a PHBL26BS fitted to a 325 motor at the moment and its a sloppy fit in the step down, I think its a 31mm inlet.

I'm going to try a PHBH28BS on my 199 Sherpa when I get the engine finished.

Big John

The Dellort on on my Bultaco has the 36mm inlet stub.

The inlet rubber is 40mm I/D onto the manifold and 36mm ID for the carb. I don't know if this is the same as a 348 Montesa item though.

[TooFastTim]

Nigel Dabster, on 29 January 2012 - 07:13 PM, said:

Dellorto on a 340 satanic thoughts you are all devil worshipers!!!

[PSchrauber]

BOGWHEEL, on 01 February 2012 - 12:03 AM, said:

The Powerjet carb is a 30mm (i think the smallest back then), and has a bush inserted into the outlet to reduce the diametre. The carb worked very well at all throttle positions, but alas the slide is now too worn out, and plastic float bowl has died from modern fuel. According to Lectron, bowls are not available as the new carbs are slightly different. Also slides and metering rods are $$$$.

Also in the throws of fitting a Dellorto to my M158 - same problem, how to adapt.

It sound like you still have a Lectron to the bike but parts are broken/unusable and expensive.

In case you are still interested in rebuilding the carb. You can ask Helmut Clasen in Ontario Canada. Helmut is a former ISDT rider and was a lokal Hercules and KTM dealer, he also sold Lectron carbs and has fittet some of his bikes with that carb. He is also very confident about Lectron carbs. You might send him an e-mail depending the parts you need for your carb.

Helmut Clasen have his own web page: Helmut Clasen, his e-mail adress is there mentioned too: (press on the turning @) in case this does not work for you: Helmut Clasen

[vintagenut]

Big John, on 29 January 2012 - 05:50 PM, said:

Hi Woody,

Is that the one that is for the Montesa 348 with Amal Mk2 Concentric?

I have measured the Mikuni VM26 it is 34mm inlet; the PHBH28BS is 36mm and the Bing a whopping 40mm.

I know we have a PHBL26BS fitted to a 325 motor at the moment and its a sloppy fit in the step down, I think its a 31mm inlet.

I'm going to try a PHBH28BS on my 199 Sherpa when I get the engine finished.

Big John

Hi John,

New poster here! I've been following this topic with great interest for awhile now. I just recently picked up a PHBH28BS for my 199A to replace what I believed was a worn out, untuneable OEM Bing. Turned out it was a damaged intake rubber that had split beneath the clamp which I discovered, of course, AFTER I placed the order for the Dellorto! Ah well...
Anyway, I'm going to give the shiny new PHBH28BS a try and was wondering if you've had a go with one on your 199 just yet? I'm hoping the jetting won't be too far off the mark but won't know for certain until this coming weekend when I have a chance to mount her up.

Any suggestions or advice here would be greatly appreciated. Love this forum!

Best regards to all -
Christian

[Woody]

Christian, I have a Delorto on my 340 with the following jets etc.

Pilot 40
Main 98
Needle tube AV264
Needle X2
Slide 4.5

Crankcase has mild transfer port changes and the exhaust has baffles removed and replaced with perforated tube and packing (like earlier models) but I doubt it makes much if any difference to the jetting. I think these settings are reasonably standard fare for most trials bikes fitted with the Delorto. It runs very cleanly and revs out very well.

[vintagenut]

Thank you, Woody! I'll take a look at what the carb comes loaded with and will aim toward what you're running. It's super helpful to have a good starting point! I appreciate the info and will report back soon.

Best regards,
Christian