Factory Pro HDJ needle jet

[mik_str]

well, finally got my carbs back and tried a test fit with slide and needle assembly....... Problem! Seems the slide is hanging and won't go all the way down (hangs up about 1/8 of the way up, and also binds the needle, which results in it needing a fairly stiff pull to get it off its seat). I have a spare carb sitting around (bought it to do some butterfly valve experiments) and, upon close inspection, it seems that the central orifice in the HDJ needle jet is slightly too small, causing the needle to get hung up..... so, what now?

- will look at trying to remove the HDJs and getting them drilled out to OEM size, or
- replace them with stock needle jets.

I just wrote Marc at FP to enquire about the removal procedure....

Nothing simple about this so far.......

[sirch345]

Talk about fighting you all the way Micky

Hang in there Bro, you're almost at the final hurdle.

Cheers for the update

Chris.

[Kev L]

What a bloody nightmare mate!

[mik_str]

such is the life of a pioneer, lol (NB: better to laugh about it......)

[tony.mon]

If it's just the interference between the needle and the needle jet itself you could ask Marc what needles he used?

[mik_str]

In essence, I asked him to "try" to fit HDJs in the carbs and I am the first to try to fit HDJ needles in VTR carbs (or so sayeth FP anyhow), so I am on uncharted waters. I knew going into this that it may not work out (though obviously I hoped it would).

I can't see them having done any kind of test fit, otherwise they would have noticed the same thing I did. In theory, the HDJ is supposed to be a direct replacement for the stock needle jet, so special needles shouldn't be needed (FWIW, the needles I am currently using are HRC units, work perfectly in the OEM needle jet). Now that they (HDJs) are seating properly (which wasn't the case when the carbs were first returned to me), it seems a shame to have to scrap the project due to a simple undersize hole..... In truth, it seems they should have checked something as elementary as the hole size, but none of us are perfect.... I noticed this hang up when I got them back the first time but assumed they would fix it all once I re-sent them. I am guilty of assuming and being silent... and so it continues....

[mik_str]

got a reply from FP, seems I need to get it hand-reamed (0.1115", straight flute reamer; jet can be left in place as it's done) and should be set to go. A pain in the butt to be sure, but I may finally get this sorted. Considering all the trouble (and money) this project has been, I damn well hope it delivers the goods......

[sirch345]

That may not be quite so bad as you first thought Micky. I'm guessing you will still need to get a machine shop to ream the thing out, not something you can do at home yourself

Chris.

[mik_str]

well, I had the ever-helpful Jack Flash (he of Superhawk forum long fuel screw fame) look around at some of his machinist contacts and no one wants to tackle it for fear of messing it up (which I respect, as it's better than trying and screwing it up) so I will be looking at sending the carbs back to FP to have them do it.... and the saga continues....

[AMCQ46]

Dear god, what a catalogue of obsticles Hope they get it right this time .

[sirch345]

What a game Micky, although it's probably best that Marc at FP does the job, even though it means posting them back, and more lost time I know.

Fingers crossed all goes well,

Chris.

[mik_str]

carbs are headed back to FP.... damn things better work as promised after all this crap....

[tony.mon]

It would've been cheaper and quicker to have converted it to Fi, Micky.......

[mik_str]

lol, you're right (or a set of FCRs)...... what's that they say about hindsight, however?

[tony.mon]

lol, you're right (or a set of FCRs)...... what's that they say about hindsight, however?

Agreed, hindsight's overrated; you can make it lighter and more streamlined by removing the mirrors.