improved clutch action

[theknurl]

out for a stator test ride;
with a new clutch oil jet Aprilia part #0268751 size 40 and a new seal in the slave [i found replacement seals at the rebuilder [because brembo does not sell kits]
the seal is marked "25 DJF 3505817 1 1/8 H" it is a standard 1 1/8 th inch master cylinder seal
seal dimentions;od 29.5mm, id 18.5 [tapered] and 4.4mm wide]
AF1 has slave seals too
'04 &'05 come with a #60 jet, '06 and later with the #40

there have been later bikes reported with the larger #60 jet so you might want to check

the jet was $8 the seal $3 best money spent on the bike yet
no creep, no drag and neutral without thinking, wish i'd done this 30,000 miles ago
Noel-theknurl

[aprsv2007fl]

congrats on the easy fix

[theknurl]

congrats on the easy fix

well it did take a while to hone the hard annodize out of the slave cylinder to smooth it, [the rough surface/return spring is where i think the air comes in as the vacuum drops] but now i have a real clutch. i recommend this mod to everyone
i only bled my clutch once in 29,000 miles, but the change is like night and day.... little wiggle of the toe and you're in neutral.
Noel-theknurl

[RSV Boy]

Hi Noel, where is this jet? sounds like a great fix.

[tdogg]

It located right above the clutch slave. The jet is rather difficult to get out with out some very small tweezers or something but it is really easy to to get to. Just pull lthe cover bolt out and the jet is behind it.

[RSV Boy]

Thanks tdogg, I have been thinking about a new slave, mines not really ever had a problem, but it is quite heavy, and I'm changing gear alot in the tight twisty roads over the mountains. Maybe MPL or Evo' ??

[MASHMAN]

Thanks tdogg, I have been thinking about a new slave, mines not really ever had a problem, but it is quite heavy, and I'm changing gear alot in the tight twisty roads over the mountains. Maybe MPL or Evo' ??

Changing gear using the clutch??? I'd be interested to find out how that works out for you, as mines quite heavy.

[StefanJ]

I'll be trying this. I just want to make sure I pull the correct bolt off.
Any pictures from the side?

Thanks

[twowheelblonde]

Noel - so just to clarify, are you recommending this as a fix for the annoying air leak problem? (lucky you don't have it) or is it just a friendlier performing clutch that eliminates those other annoying issues.

[sjruckle]

Attachment 84019

Here's a shot from the side. I hope you can see the red arrow.

Remove that bolt and the jet is underneath. You don't have to drain the oil, but a few tablespoons will drain out anyways. Use as big a screwdriver as you can get into the slot of the jet since you don't want to damage the soft brass when un-threading it. Grab the old one with tweezers or something and take it out.

Install the new one and only make it as tight as needed to keep it from un-screwing itself. It's not like the jet is holding anything together, so almost no torque is required. Install the bolt again and torque it to 100 in-lbs. Go ride and make sure it doesn't leak!

Please keep in mind that a badly-bled clutch master and/or slave cylinder will cause the same problems, so check that first since it doesn't cost anything.

[kzmille]

...The #40 jet (that you just installed) has a larger hole than the #60 that the engine came with. Since more oil is being allowed onto the clutch pack it will lubricate the plates more and erase some little problems (like not being able to find neutral and having the bike creep forward while in gear with the clutch in)...

sjruckle,

This information about jet sizes and numbers is wrong and should have been challenged. On these oil jets, like carburetor jets, the higher the number the larger the hole, the lower the number the smaller the hole.

[amauri]

sjruckle,

This information about jet sizes and numbers is wrong and should have been challenged. On these oil jets, like carburetor jets, the higher the number the larger the hole, the lower the number the smaller the hole.

Correct.

The original intent of the smaller main shaft oil jet was to supply more oil pressure to the crankshaft.
As a result, neutral became a little easier to find.

[Peter S]

I just put the #40 jet in the Falco and the RSV and it has made finding neutral much easier in both. I have also noticed, on the RSV in particular, that gear changes have become smoother right through all gears. Well worth the trouble.

[theknurl]

the oil jets are marked as to the diameter in 100ths of a millimeter

carb jets are marked by cross-sectional area
ever see the square in a square stamped on Mikuni or Keihin jets?

Noel-theknurl

[....]

The #40 jet (that you just installed) has a larger hole than the #60 that the engine came with.

incorrect.

sjruckle,

This information about jet sizes and numbers is wrong and should have been challenged. On these oil jets, like carburetor jets, the higher the number the larger the hole, the lower the number the smaller the hole.

correct.

'04 &'05 come with a #60 jet, '06 and later with the #40 Noel-theknurl

Noel, I'm not sure where you got this information, but after checking my bike (07.5) I found that the #60 jet was used, and not the #40. I ordered the 40 from Af1, and installed it.

Now here is why I did this:

I didn't have any issues with the bike creeping unless there was a shit-load of air in the lines/master. And even then, I only had that issue happen to me once (pre-slave install). I've since installed the MPL slave (from matrixmotosports.com) and hadn't had any significant issues with the lines since. In fact, bleeding is a rare necessity nowadays. That said, I still would have a slight bit of trouble finding neutral from first gear, however could always find N from banging it down from second.

After installing the #40 jet, I can find N from either 1st, or 2nd gear. I'm posting this for anyone who has an 06+ bike, who read this thread, and deduced to not install the #40 jet based on earlier posts that advised that the 06+ bikes already had the jet installed. Mine is a 07.5 and did NOT have the #40 jet installed. It had the #60. I know this, because once the old one was out, I compared the two and seen the differences with my own fuckin' eyes.

Ever since I've installed the Jet, as per Knurls advice, finding N is cake. I really hope this post helps some of you guys. I imagine some of you with 06+ bikes disregarded the new jet based on the misinformation on this thread. My bike did have the 60 in it, and changing it to the 40 jet has made a significant difference in finding N.