F2 YPVS jetting

[dezcbr]

I have just done a full rebuild on my f2 it was running TSA pipes prior to strip down, I have rebuilt the standard power jet carbs and note that it is fitted with 290 main jets and the air box lid has a few holes drilled in it. I have bought some Alonze / Muttsnuts exhausts and intend to fit them once it's finished, can anyone offer advice on approximate jet sizes required? I note that the 290 seem big compared to a standard bike but it always seemed to run well with the TSA's.

[midlifecrisisrd]

I'd be checking that the power jets have not been blocked off

290 sound like 31k jetting for an airbox mod and pipes

290 on power jet carbs with the 55 power jets makes 345 which is like pod filter jetting.

PJ carbs don't like filters as it Micks them up so is common to block them off and jet as 31k

Steve

[dezcbr]

Mar 29, 2021 12:41:21 GMT 1 midlifecrisisrd said:

I'd be checking that the power jets have not been blocked off

290 sound like 31k jetting for an airbox mod and pipes

290 on power jet carbs with the 55 power jets makes 345 which is like pod filter jetting.

PJ carbs don't like filters as it Micks them up so is common to block them off and jet as 31k

Steve

Thank you for your reply Steve, would the power jets be blocked off in the connecting pipes or would the jets themselves be blocked off? As far as I know it hasn't been previously fitted with pod filters
Dez

[midlifecrisisrd]

Usually the rubber tube between the power jet in the float bowl and the spigot on the body has a ball bearing or similar shoved up it

I know power jet carbs can be tricky to jet when not 100% standard so may have been done due to the airbox mods

Either that or the mods are affecting the pj operation so jetted to correct this

Steve

[dezcbr]

Mar 29, 2021 13:42:02 GMT 1 midlifecrisisrd said:

Usually the rubber tube between the power jet in the float bowl and the spigot on the body has a ball bearing or similar shoved up it

I know power jet carbs can be tricky to jet when not 100% standard so may have been done due to the airbox mods

Either that or the mods are affecting the pj operation so jetted to correct this

Steve

Thanks again Steve, I appreciate the advice I will go and have a look.

Cheers
Dez

[dezcbr]

I have stripped the carbs and the power jet circuit is clear. I presume the jets must be due to the six 10mm holes drilled in the air box lid and the pipes which are prototypes made TSA when he first started making pipes.

[midlifecrisisrd]

That's good news

Have a look under the filter and see if the middle section is drilled as well

I suspect the inner snorkel is out as well

Steve

[dezcbr]

Mar 29, 2021 18:49:27 GMT 1 midlifecrisisrd said:

That's good news

Have a look under the filter and see if the middle section is drilled as well

I suspect the inner snorkel is out as well

Steve

Thanks Steve, I will go and investigate further
Dez

[dezcbr]

The snorkel is missing from the air box intake and there are no more holes in the air box.

[midlifecrisisrd]

Still sounds like big mains to me but not used pj carbs in a modded bike

Try it and see, I wouldn't think it would be vastly different between the pipes

Steve

[dezcbr]

Mar 30, 2021 8:55:36 GMT 1 midlifecrisisrd said:

Still sounds like big mains to me but not used pj carbs in a modded bike

Try it and see, I wouldn't think it would be vastly different between the pipes

Steve

Thanks Steve, I will give it a whirl, I know it runs rich which won't be a bad thing when running in. If it doesn't pull cleanly I can always put my TSA's back on for the time being. I'm tempted to block the holes in the air box lid and see how it behaves on jetting a couple of sizes up from stock, maybe one to ask Dave
All the best
Dez