Jetting

[m in sc]

I thi k you're compensating the needle position with the pilot 

[pdxjim]

Well, raising the needles is certainly easier than changing jets, but it won't even idle with the 42s.

That shouldn't have anything to do with the needles.

[Barrie]

Why wont it idle?

[m in sc]

thats very odd. ive never seen one need over 45's on an rd of any kind. BUT, they are all different. i mean, stuff the 45's back in and richen the needle? also make sure the float level is correct, its very easy to get them off with the way the bowls come off.  where is the air screw set?

[pdxjim]

Getting closer!

Raised the needles, and it's almost rideable.

Current setup:  42 pilots, airscrew 1.5 out.  JJH @#4, 145 mains.

Pilot is clearly too small as idle hangs.

Once you get past the pilot the needles seem much better after moving from #2 to #4 so will leave them for now and go back to the 45 pilots at maybe 1-1.5 on the air screws.  Polini bois have 48 and 50 pilots if I need them.

Biggest hassle of these PWK's is the idle screw and air screw is on the left side on both carbs, meaning you gotta pull the right carb off to adjust.

[oxford]

Only thing I can add is, if you are trying to compare jet sizes to what others use make sure that those aftermarket jets are indeed the same size and genuine Keihin parts.  Number for number they may be different sizes.

It doesn't make any difference in the end when you get there but may make the road getting there a little more bumpy why you need a 50 when everyone else uses a 42.

[pdxjim]

Only thing I can add is, if you are trying to compare jet sizes to what others use make sure that those aftermarket jets are indeed the same size and genuine Keihin parts.  Number for number they may be different sizes.

It doesn't make any difference in the end when you get there but may make the road getting there a little more bumpy why you need a 50 when everyone else uses a 42.

True.

Only aftermarket jets I'm using are Polini, and they have the rep of being very consistent and as good as genuine Keihin. 

Whether they flow the same as a genuine Keihin of the same number?   Who knows.

[m in sc]

Only aftermarket jets I'm using are Polini, and they have the rep of being very consistent and as good as genuine Keihin. 

Whether they flow the same as a genuine Keihin of the same number?   Who knows.

this may very well be it. My pwk numbers i gave was from my lc topped motor from way back with pwks and specII pipes, unported, so, very similar setup. I actually dynoed the bike, and the only jetting change was from a 152 to a 150 on the main and one clip richer (to 4). I also remember the airscrew seemed to respond best at 1.25 out.  I put down 52 rwhp at that time back in.. 06 i think?

[pdxjim]

Ugh.

This is so weird.

Current setup is 45, 1.5 turns out, N68A #3, 145.  Ed Erlenbach stage 2 port, squished head, vForce3 YZ85 reeds with spacers, Garrett's pipes.

It starts easily on one or both chokes.  Idles easily when cold, and runsand revs pretty good when cold.

I can get about two blocks around my neighborhood before it starts acting up.  Doesn't want to idle, feels very hollow down low.   It starts bogging and missing and feeling like it's running out of fuel.

I'm about ready to decide jetting may not be the problem?

All electrical and charging system is stock original 40 year old parts.  Timing is set to the factory marks, but since it's all new crank/rods/pistons/etc, I have a call out to a friend with a timing setup so I can verify it's correct at 1.8 btdc.

What else would cause shit running when hot?  Bad coil maybe?  R plugs and the wrong plug caps?

... and by hot, I really mean just warm.  Like 2-3 minutes idleing on the stand and  2-3 minutes on the road it all goes to shit and I have to use the chokes to get home.

... but maybe the fact that it runs so much better on the choke means it really is jetting?

This fcuking thing is pissing me off.

[oxford]

Before it moves from jetting, can you just confirm that all the jets you are using are all aftermarket Poloni or are some of them genuine Keihin?

[rodneya]

Are you getting fuel through? I have had a bad gas cap breather cause fuel starvation after a few minutes riding.
Loosen the cap and try ride a bit.

Electrical issues dont usually get better when the choke is on

[pdxjim]

Are you getting fuel through? I have had a bad gas cap breather cause fuel starvation after a few minutes riding.
Loosen the cap and try ride a bit.

Electrical issues dont usually get better when the choke is on

Clear fuel lines full of fuel.

No issue there.

[pdxjim]

Before it moves from jetting, can you just confirm that all the jets you are using are all aftermarket Poloni or are some of them genuine Keihin?

All genuine Keihin jets from jetsrus.com in there now.

So far only the 42 pilots were Polini and they only lasted one test ride.

[pdxjim]

Lol ... to further confuse things, here are the plugs:

[pdxjim]

Ok, getting closer again.

Raised the N68A needles up to #4 and made it around the hood without resorting to the chokes to get me home.

Still hollow just off idle, but saved by the fat needles, I guess.  Goes "Baaaaaa-whooom" when you whack the throttle, and hangs before settling down.

Going up to 50 pilots!