Pilot jet

Paddy

Paddy

Junior member
Location
England
Just rebuilding a set of RGS carbs and they have #75 pilots fitted ?
Any recommendations ? the guy says it ran ok but one mans ok is another mans rough
I would think #60 would be more like it but as most of the books cant agree i just wondered what the general consensus is ?
 
75 seems extreme to me Paddy. The factory specified 65, but I agree with your thoughts on going a bit smaller on that and also used 60. Having said that, I'm not running BTZ ignition. Standard airbox and filter, albeit drilled to Corsa spec (two big holes in the bottom) and no crankcase recirculation
 
Thanks Rob, yes in the Ducati world its common with modern fuels to come down from 65 to 60 although you shouldn't confuse ethanol fuels burning a bit sooty with being a bit rich.
Its always tricky rebuilding carbs as you never really know what the customer has done to his engine. Normally i just replace like with like but 75 seems a bit extreme.
 
65 with Witt ignition and religiously using Esso supreme which is currently ethanol-free. Bike runs fine and after some attention to carb balancing trickles along in traffic below 2000rpm quite happily.
 
60 would be my choice, albeit a tad rich for many stock RGS, makes for a better transition pilot to needle taper in city traffic. HTH j

** at a guess the 75 was an attempt to mitigate the pinking at low rpm to moderate/full throttle control in higher gears. Way too big in any case.
 
Stoutgoose said:
65 with Witt ignition and religiously using Esso supreme which is currently ethanol-free. Bike runs fine and after some attention to carb balancing trickles along in traffic below 2000rpm quite happily.
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It may be ethanol free, but it's lead free.
15 years ago people were being religious with the last leaded petrol in the UK, wouldn't go near lead free.
Now it's ethanol.

Result of that is the bike's not being ridden.
Get out there and ride. They'll work fine on anything.

Paul
 
Is lead-free an issue Paul? The heads are aluminium with hardened seats. I have always understood that lead-free was an issue in iron heads with soft seats.
 
No, lead free isn't an issue but my point was that it caused many a sleepless night and long debates some years back and now it's on again for a few drops of alcohol.
Lead is to do with seat material irrespective of head material.

Paul
 
Thanks, that’s what I understood. However the common belief is that ethanol is extremely corrosive to older fuel systems that contain aluminium components, or glass fibre fuel tanks. It also facilitates corrosion within steel fuel tanks.
 
Stoutgoose said:
Thanks, that’s what I understood. However the common belief is that ethanol is extremely corrosive to older fuel systems that contain aluminium components, or glass fibre fuel tanks. It also facilitates corrosion within steel fuel tanks.
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Glass fibre, yes.
As for the rest, that's true of all fuel.
You're pumping more water in your tank when you fill up at the petrol station than alcohol will extract from humidity in the air.

I tested by leaving rubber carb gaskets and a set of floats with float needle 3 months in some E10.
Result: nothing, nada, niente, rien.

But I've got nothing to sell.

Paul
 
Yes and no. A combination of experimentation if you are able to test without destroying something you cannot afford to lose may yield results as Paul has shown. However online research of results obtained from objective testing is useful, and forum member experience is also often invaluable. Not sure about Facebook though?
 
Stoutgoose said:
Yes and no. A combination of experimentation if you are able to test without destroying something you cannot afford to lose may yield results as Paul has shown. However online research of results obtained from objective testing is useful, and forum member experience is also often invaluable. Not sure about Facebook though?
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Certainly. It's sometimes difficult to know who's behind the objective testing.

Paul
 
I am pretty sure The Ponds Institute is THE AUTHORITY. It only took them 7 days to get results. I really hope that wasn't Fake News.
 
Vince said:
I am pretty sure The Ponds Institute is THE AUTHORITY. It only took them 7 days to get results. I really hope that wasn't Fake News.
Click to expand...

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we all crapped ourselves at the loss of lead, and many, me included used additives, in the end I settled on Castrol valvemaster because of te conveniance of the measuring top incorporated into the bottle. Now we are all crapping ourseves at the addition of Ethanol (and any way what happened to Methanol?) I have found that even the storage time of six weeks and its cattled also to be untrue, there doesnt seem to be the plethora of additives to counteract the Ethanol either, so what does one do? for me its carry on regardless, but then TOG is ony 7.8:1 which probably helps and before any of you H/C lads chime in, if you THINK your pistons are 10.5:1 an accurate measurement will usually prove that the quoted figure is just a "come and get me" printed line on the box.

CLEM
 
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