Carby upgrade on 2001 570 with Dell Orto carby?

[chocwheaton]

I've just bought a second hand SM570R and it has the stock Dell Orto carby. I've heard that they are not that good, and my bike is running pretty crappy. This Dell orto is unhappy sitting on constant revs. Sitting on a speed limit is hard work. It surges and jerks around like nothing I've ever ridden before. The only time it's smooth is when just taking off, when doing 60 and over, or when accelerating. The bike starts in one or two kicks all the time. with a little choke with cold. It also idles well.

My questions is, can these Dell Orto carbs be set up well so the bike is reasonable smooth in all situations, or should I not waste my time and just get a decent carby instead?

Anyone with a bike with one of these carbys like to let me know how well their's is running?

BTW...in intended use of this bike will be track only, so I'll be mostly on the gas or on the brakes, but in its current state I'd hate to try to ride it fast on a track.

Cheers

Greg

[Agitator]

I've got an older 577 with the dell orto... I've had idle speed issues- it won't stay at the same speed while idling. I've tried many things to remedy this.

As for keeping the revs consistent, the carb is great. First gear is a little jerky, but only a little. When I cruise in 2nd, 3rd, or higher gears, maintaining the same speed seems pretty easy. When I ride again, I'll pay extra attention and post-up again. The carb is also really, really snappy and responsive for a non-pumper carb, imo.

My only complaint is the idle speed variations. Other than that, I love the carb.

Since yours is newer than my '94, it may be designed differently.

George Erl knows a lot about this stuff. I bet he could answer your question with ease.

[Ride]

I had a 93 610 with the Delorto and it always started and ran great which was a huge surprise to me. I liked the one I had.

[ryboj]

You can always upgrade to the Mikuni that was used on the 02 570's, no?

[Agitator]

Does the mikuni make more power, or is it just more controllable/responsive/smooth?

[ryboj]

I can only mention from what I've read and researched, nothing first hand. However, I was inches away from converting a 01 TE400 to a Mikuni for all the reasons mentioned below.

The mikuni is better at everything (assuming the Delorto is not tuned perfectly), but power differences should not be noticeable.

However, also from what I've read, a perfectly jetted Delorto makes great (very acceptable) power.

People make the switch for other reasons, power not ever being one of them.

Typically for starting/power delivery reasons...

?

[Norm_Matzen]

I used to have a '95 ATK 605 with a Delorto carb. It ran perfect. Started easy with the kick even tho it had the magic button and with one jet setup it ran good from sea level to 10000ft!

I now have a TE510 and asked on this forum about putting my spare Delorto on the husky and you would think folks thought I was ready for the funny farm!!

For smooth idling, first make sure the idle jet is the right size. That is, the idle screw should be around 1 1/2 - 2 turns for best idle. Then, raise the idle speed to a slightly too high speed with the speed adjust. Then, adjust the idle screw so it is just between slowing from too lean to slowing from too rich. Split the difference. Then, reset the idle. Now, the idle should be stable and it should start very easily. 'Course, the engine must be warm for the above adjustments.

?

The Ear Plug Guy

[chocwheaton]

You can always upgrade to the Mikuni that was used on the 02 570's, no?

That was my thought if this Dell is not going to work.

[Kongo]

I have an 01 TE 570 with the DO carb and it has absolutely no issues. I've read all the post about the problems with this carb, but as I stated once before, I must have gotten really lucky because I haven't touched it since I bought it and throtle response is spot on under all conditions. Starts fine and runs great all the way through. However, I can confirm that starting is difficult if you tip it (especially on a decent hill). There are a couple of posts with a drill for helping start it in the event of a spill.

[Agitator]

I used to have a '95 ATK 605 with a Delorto carb. It ran perfect. Started easy with the kick even tho it had the magic button and with one jet setup it ran good from sea level to 10000ft!

I now have a TE510 and asked on this forum about putting my spare Delorto on the husky and you would think folks thought I was ready for the funny farm!!

For smooth idling, first make sure the idle jet is the right size. That is, the idle screw should be around 1 1/2 - 2 turns for best idle. Then, raise the idle speed to a slightly too high speed with the speed adjust. Then, adjust the idle screw so it is just between slowing from too lean to slowing from too rich. Split the difference. Then, reset the idle. Now, the idle should be stable and it should start very easily. 'Course, the engine must be warm for the above adjustments.

?

The Ear Plug Guy

In my situation, I've done those exact adjustments. My idle speed inconsistencies stem from free play in the slide/idle speed screw interface...

With slack in the throttle cable, I release the grip- the throttle closes, but takes a few minutes of vibration to settle into its resting spot. If I turn the speed up, the bike idles too fast, then slows down, but is still too fast...

[chocwheaton]

I have an 01 TE 570 with the DO carb and it has absolutely no issues. I've read all the post about the problems with this carb, but as I stated once before, I must have gotten really lucky because I haven't touched it since I bought it and throtle response is spot on under all conditions. Starts fine and runs great all the way through. However, I can confirm that starting is difficult if you tip it (especially on a decent hill). There are a couple of posts with a drill for helping start it in the event of a spill.

That's interesting. I think it's worth trying to get this D-O set up right and see what it's like.

Of course my bike starts and idles great already. It's the surging when at a constant speed that's the issue.

Cheers

Greg

[Barrobuild]

Surging usualy means lean,try raising the needle one knotch,BTW the Delodo is a pumper carb,have a look into the inlet when turning the throatl and you should see a stream of petrol,I tried mine with it disabled and it would not snap,classic lean bog,the reason the other bloke is having issues with constant idle is worn slide,bloody expense to replace,stick your finger into the end and try wiggling it,bet it moves around.Another problem with older deordos is the seal on the bottom of the choke plunger,they get hard and a divot forms and they dont seal to well,constant rich running,pry the rubber bit out and turn it over,use a sowing needle,its not easy but well worth doing,

the joys of owning 30 year old Italian road bikes with Delordo Carbs.

[Husky62]

If you are ready to make the swap I will buy the DellOrto from you!!

Thanks,?

I've just bought a second hand SM570R and it has the stock Dell Orto carby. I've heard that they are not that good, and my bike is running pretty crappy. This Dell orto is unhappy sitting on constant revs. Sitting on a speed limit is hard work. It surges and jerks around like nothing I've ever ridden before. The only time it's smooth is when just taking off, when doing 60 and over, or when accelerating. The bike starts in one or two kicks all the time. with a little choke with cold. It also idles well.

My questions is, can these Dell Orto carbs be set up well so the bike is reasonable smooth in all situations, or should I not waste my time and just get a decent carby instead?

Anyone with a bike with one of these carbys like to let me know how well their's is running?

BTW...in intended use of this bike will be track only, so I'll be mostly on the gas or on the brakes, but in its current state I'd hate to try to ride it fast on a track.

Cheers

Greg

[Norm_Matzen]

Actually, my ATK had a non-pumper Delorto. I think the non-pumper had a totally different needle jet to keep a supply of gas ready when the throttle was wacked open. Mine didn't hesitate.

Right about the lean surging and raising the needle.

Also, lean idle conditions can cause slow return to idle on throttle closure.

And---The lower edge of the slide has a notch where the idle speed screw presses. This surface can take a set from the screw and not have a well defined position. Sometimes one can remove the slide and file this area flat again and idle adjust is stable again. But, watch for the slide to have a notch worn in by the screw, then the idle cannot be raised as the screw can't go up far enough. Once you take it apart, you will understand how it works.

[Agitator]

I've had my '94 DO apart over five times, and cannot find any evidence of a pumper mechanism. I could have missed it, but I'd be surprised if it had one.

I've already messed-with the adjuster screw and the part of the slide that hits the adjuster. I was only 1/2 turn out on the pilot screw, so I went from a 62 pilot to a 60. now, it's a bit more stable, but is happy with the screw 1 turn out.

not to hijack or anything ?

[ryboj]

Might want to check out:

https://www.thumpertalk.com/classifieds/showproduct.php?product=25754&cat=all

[Agitator]

very interesting.

[Barrobuild]

If there is a plastic gadget attached to the top of the card that fits into a slot

in the slide then you have an accelerator pump,my 92 TE 350 had one,but I think that was a 34mm carb,some Ducatis came with 40mm carbs that did not have a pump or choke,they had a tickler,meant in the nicest way,Buton that held the float down.

[Agitator]

hmm. I might just have to take a look at the carb later and see what I see.

[indian70]

Im thinking of slipping on bing 54 have to check jetting