What d'ya reckon?

[Phil_H]

Early Varadero (softer state of tune than vtr)
Cruises fine but engine feels a bit rough & labour when under load between 2-3.5k.



Currently stock pilots - 42s
Std needle raised .5mm
Mains are 158/160 (down from 168/170)
Std filter & std cans.

Thinking;
48 pilots
Std 1 needle shim
150/152 mains

Whadda ya reckon? Sound about right?

Cheers in advance, not much info in 'dero land

[AMCQ46]

agree, its lean on the bottom end so upping the pilot and the needle will help.

I might be tempted to make less of a change on the mains as they are not so far out

[Phil_H]

I know what you mean about the main jets but my reasoning was, I'm adding 5 to the pilots that run all the time so the 8 that I'm dropping on the mains is realistically only a reduction of 2 or 3 if you know what I mean!

[AMCQ46]

I don't think you will see the effect of the pilots on the top end, so not sure you can add and subtract all the jet changes to come up with one number

[VTRDark]

Agree, the pilot has very little effect on mains. Raising the needles will have more of an effect on the mains than the pilot.

(:-})

[Phil_H]

The pilot jet has no effect on the main jet but as it flows fuel all the time, it does have an effect on afr at higher revs, albeit slight.
I'll try the above jetting & see how I go :!

[Phil_H]

Ok, 48 pilots & 150/152 mains fitted, 1 stock .5mm shim under the needle.

Bike has more punch 2-3k, holds constant throttle ok between 3-5k BUT coughs & stutters when under load between 3-5k, the higher the gear and more aggressively the throttle is opened the worse it is.
5k up pulls strongly.

I'll pop an extra 1 or 2 (.5mm thick) shims under each needle.

Question how much can the needle be lifted before it starts pi$$ing fuel out with the slide closed?

Cheers for any forthcoming input

[AMCQ46]

worth putting the mains up a bit as it didn't run badly at high revs before

[Phil_H]

It runs fine at high revs (5k-red line) now, its 3-5k thats the problem.

I'm tempted to go with 2 extra shims under the needle. Too much?

Phil

[Stephan]

It runs fine at high revs (5k-red line) now, its 3-5k thats the problem.

I'm tempted to go with 2 extra shims under the needle. Too much?

Phil

My opinion is you are too rich with 48 pilots, this will make things even worse. Worth to try 45 and needles at the lowest position. But I don't know it for sure. Another option is go back to 42, raise needles as mentioned and adjust pilot screws settings.

e: together with smaller pilots, I would go at least one size up on mains.

[Phil_H]

Interesting feedback, the previous dyno was with 42 pilots, 158/160 mains and an extra shim under the needle & it was lean bottom end, fairly rich top end.
Gut feeling, 3-5k is lean.

Just debating an extra 1 shim or 2 OR do I try 2 front, 1 rear... :/

[Stephan]

you made big change. From lean to rich ... Top end looks maybe good, but running too lean is not safe for engine, it is hard to recognize in these revs. But do whatever you consider good, I just put my two cents :-)

[Phil_H]

Cheers for the input,
I stand to be corrected but I'm having trouble seeing how pilots would go from quite lean below 4.5k to being rich to the point of bogging down at 4-5k with just an increase of 2 sizes and in conjunction with smaller mains.

Guess I'll have to suck it and see
A shim or two will either make it better - or worse!

[VTRDark]

Up to about 4.5k your running lean which is not a bad thing low down (unlike up top/high reves) and gives more rideability, but you could do with richening that up a tad. Needles don't need richening up as they are already falling towards the rich side past 5k so if anything I would remove shims from the needle not add some. I can't see how you would need bigger pilots than 48's so I would question the fuel mixture screw adjustment and/or the transition onto the slide. How's the bike idle, is it smooth with no fluctuation on the rev needle?

(:-})

[Phil_H]

The dyno graph was with 42 pilots - the bike ran ok but felt rough/labouring under load between 2-3 1/2k. Any leaner, no shims etc made the bike cough & stutter under load which is why I've gone 48 pilots & reduced the mains a bit.
2-3k feels better but the cough/stutter has moved to 3-5k hence my thought of raising the needles a bit.

Tickover was perfect before, merely 'ok' now but a bit wooly - needs richening a bit.