Dell orto - just about everything was wrong....or was it the needle all along?

Paul, I'd love you too. seriously!

I don't always communicate well and a simpler approach is often better understood with owners.

cheers

Taffy

Actually the mistake is only easy to spot afterwards - well i think so.

it only came to light in the last batch of testing when I was using the High Taper Start Special Needle.

"42 to 40PJ
DR276 to DR274
FS happy at 0 but left at 0.5 turns out. still burbling.


so DR274 to DR272
starting is the best i can recall, i can't even hear the button, it is just running. only ever been like that once before in all the tests.
Curates egg though (so good in parts) it got richer at idle and goes dry in the pilot area. "

The atomisers get smaller but the mixture got richer at idle. this is the opposite of what I said in explaing each function in the carb at the beginning of all this.

the reason should be that sucking through a smaller area makes the vacuum/suction all that much greater. the greater the air speed, the more fuel gets pulled but at a greater pro-rata too!

why didn't I spot it at the beginning?
well if I was going to spot it, everything else had to be so sweet that it was the obvious problem but the standard jetting is poor enough to just disguise it as another lumpy, bumpy cough. The only needle it could have worked on is the high-taper-start K51 but at 2.52 (45mm up needle taper start) wide in a DR276 it was too lean.

so the only way I could get fuel in past those low taper start needles (nearly all at 36mm) was to have a huge atomiser. I'm guessing that the gap was huge which in itself would have lowered the suction and air speed up the side of the needle.

I rode all day yesterday and when really warm, the engine was slower starting but always reliable to start. may see if it'll take a DR270 atomiser next.

Taffy

As this is something of a marker thread for me, I'd like to draw attention to the Fuel valve on all the 38 and 40mm PHM roundslide carbs. so that'll be pretty much all carbs from 1997-2003 = 7 years.

The fibre washer that comes with a new Fuel Valve(FV) can vary in size from 0.4 to 0.7 to 1.0mm. Usually the one that is taken out is cherry red and the replacement dished up is a fawn in colour.

they are often 1mm but that is too big! certainly for the 40mm carb it is. they need to be nearer 0.6-0.8mm.

the tangs should ideally be flat and not bent to a bent shape just to please you!

I usually supply two different ones in my kits so that you can get it right.

regards

Taffy

Taffy said:

Paul, I'd love you too. seriously!

I don't always communicate well and a simpler approach is often better understood with owners.

cheers

Taffy

Click to expand...

Taffy,
not ignoring you, just haven't yet found the time to get to my workshop. Hopefully at the weekend.
Cheers... Paul

This could be very handy info in a hopefully short while.
Ive got an 02 fe650 on the bench at the mo.
Once the engineering has been sorted and a bunch of new parts sourced I can start sorting one of the two Dellortos that came with.

Cheers Taffybro.

I'm with Huskyfatman, I've got some ATK's with Dellorto's and never had a problem with them. Never had to adjust the settings. They came jetted for sea level in Salt lake city Utah and I'm at sea level in Australia on the other side of the planet and they all run sweet. Not only that but they start first kick all day every day.

I never understood why they didn't work well on the Berg's and KTM's. I remember back in the day meeting some Berg riders on mid 90's models who had trouble with backfiring and blowing the Dellorto's off. And some KTM's backfiring through the carb, igniting the air filter and burning the bikes to the ground.

But you're both saying that other vehicles than Husabergs were great. that is fine, but this is about a bike with a problem AND, the electric start is twice as fickle as the kickstart as many would perhaps testify.

I'm not expecting a rush of people forward to say their bikes don't start. But I love it when i go into detail, people always loop the argument back to;
I don't have a problem; na-nha, na-nah-narrrr.
i just get on it and ride
carb what?
problem what?
who cares anyway?
I have a 2019 FE*** and don't have this problem.
look who's a geeky ******!

I get plenty of emails thanking me for my "easystart" and the kit I have made and sold specifically for the FE501e 2001-2003 which I named the "Berg Booster" kit. But a sself-praise is no praise...it counts for little.

it's a phuqing long process breaking down what ghappened to these carbs. what went wrong. but the last diagram i put up was of the difference in the starting needle and the one I am at now.

if you go back to the beginning these things didn't run at all well and the lines between each needle were a hairline different but now look above at the difference! and all the time I had to try and keep the bike starting and running sweet.

a bit like having a fight on a stagecoach with one hand but driving the team of horses with the other!

The Keihin Carb and my Jetting Kits
I'd also like to point out that what has been the correct jetting for the FE380 all the way to the FS650 Husaberg. with the correct needle, i make the same kit work for every single one of all the engines in the range and all the cams. all i do is change a main jet and a pilot jet and one kit does the lot!

I therefore expect this needle to have the same result. Before i made the "SPECIAL" needle this spring, i pretty much had it right but the atomiser was off the scale, the pilot jet was off the scale and it still wasn't perfect when i had a 4-clip needle on the 7th needle clip because I had put them there myself!

the special needle allows the original atomiser and a medium small PJ along with a medium height slide cutaway.

THAT'S 4 THINGS THAT ARE SANE AGAIN. atomiser, needle, PJ and slide cutaway.

I'm trying to get this this time so that you buy the needle, flame me and then buy all your bits off someone who doesn't know what he's doing, we then get you all running in a circle round a fire 'Indian style' and all end up disappearing up our own arses!!!! Now that would be a sight worth seeing!!!!

we could then extract spark plugs from our arseholes exclaiming; "that's Champion!":bounce::bounce:

I can't wait!

Taffy

But you're both saying that other vehicles than Husabergs were great. that is fine, but this is about a bike with a problem AND, the electric start is twice as fickle as the kickstart as many would perhaps testify.

I'm not expecting a rush of people forward to say their bikes don't start. But I love it when i go into detail, people always loop the argument back to;
I don't have a problem; na-nha, na-nah-narrrr.
i just get on it and ride
carb what?
problem what?
who cares anyway?
I have a 2019 FE*** and don't have this problem.
look who's the geeky ******!

I get plenty of emails thanking me for my "easystart" and the kit I have made and sold specifically for the FE501e 2001-2003 which I named the "Berg Booster" kit. But as self-praise is no praise...it counts for little.

it's a phuqing long process breaking down what happened to these carbs. what went wrong. but the last diagram i put up was of the difference in the starting needle and the one I am at now.
View attachment 8129
if you go back to the beginning these things didn't run at all well and the lines between each needle were a hairline different but now look above at the difference! and all the time I had to try and keep the bike starting and running sweet.

a bit like having a fight on a stagecoach with one hand but driving the team of horses with the other!

The Keihin Carb and my Jetting Kits
I'd also like to point out that the kits have been the correct jetting for the FE380 all the way to the FS650 Husaberg. with the correct needle, i make the same kit work for every single one of the engines in the range and all the cams. all i do is make a change of main jet and pilot jet and then one kit has does the lot!

I therefore expect this needle to have the same result. Before i made the "SPECIAL" needle this spring, i pretty much had it right but the atomiser was off the scale (the biggest and last at DR276), the pilot jet was off the scale (at 58) and it still wasn't perfect when i had a 4-clip needle on the 7th needle clip (because I had put the clip grooves there myself) and the slide cutaway was just under 7mm!

the special needle (on a sensible C2) allows the original atomiser, and a medium small PJ, along with a medium height slide cutaway.

THAT'S 4 THINGS THAT ARE SANE AGAIN. atomiser, needle, PJ and slide cutaway.

I'm trying to get this this time, so that you buy the needle, flame me and then buy all your bits off someone who doesn't know what he's doing, we then get you all running in a circle round a fire 'Indian style' and all end up disappearing up our own arses!!!! Now that would be a sight worth seeing!!!!

we could then extract spark plugs from our arseholes exclaiming; "that's Champion!":bounce::bounce:

I can't wait!

Taffy

I have a husaberg 600 fe 1995 with a flat slider dellorto Carb.
8 years with this bike now, i have been through hell and back
In the first year, low idle and horrible to start. Vent from 38 to ca 48, a little better.
Some years later i made a separated engine breather-vent, airfilter channels with pre-filter and went from sparkplug 8 to 7.
The idle starten to get low again and I did a idle- screwmod so the slider could be set even higher, went pretty good a couple of years, the idle in particular, could still be pain in the *%# to start sometimes.
The coil broke down this year, the bike improved in performance with the New coil, but short after hard to start again and idle starten to get low again, I droped the needle one clip. The idle went higher and I adjusted the slider down a bit.
The bike now starts better than ever, first, second or Third kick period
Powerfull idle, no doubts in the register and high revs!

I have over the years checked the carb for dirt inside, but it has always been absolutly clean!
The rubber-air intake between the cylinder and carb has to 100% sealed, or you Will get problem in many ways, not easy to detect IF the leak is small, like it was in my case

Correction, Im using idle jet size 52.

One tip to dellorto users is to check the needle play, both horizontally and vertically.
On old bikes especially the big engines have strong vibrations that will wear down parts on and around the needle. In my case I was lucky that I could use shims to stabilize the needle, the wear of the needle-valve and needle-jet could I compensate by lowering the needle one clip.

Hey Mazzoki.
If you are asking if you can compensate for wear by lowering the needle then yes but no.
Yes it will improve it but no it will not solve the problem.

Needle and more importantly, needle seat(the brass bit in the carb body the needle slides in) wear is a product of the pulsating forces from the motor banging the needle back and forth whilst it is moving up and down which creates an oval shaped hole in the seat and thus the round needle no longer fills the oval hole to control fuel flow.

Ideally you should renew both needle and seat.

If thats not what your asking then ive just wasted a few minutes of my, and yours if youve got this far...... time.

The bike (the engine)has run flawless this autumn on the enduro-trail/track I ride.
Im just sharing my experience!
I have red about oval-wear on the needle-jet but in my case the wear was as round as it possible can be, so no problem at the moment