84 500 mid range flat spot

[Barclay]

Running a nice 84 500 desert racer at the moment .
its running 310 main 45 pilot on the third clip on the needle .
seems to have a eighth to quarter throttle lag where it dosnt boogie .top end is fine ,pulls clean crisp
starts second kick .It is on the lean side of good but running 32 to 1 synthetic
I started dropping the needle and some improovment was found .
Could it be the over priced Boysen reeds ?
I dosnt splutter it dosnt miss .I just have to crack her half open to get a good response
Problem is it then stands up an bolts .not very controlable
It was never an issue before it split a reed petal              cheers Boots

[frostype400]

I have heard people going back to stock reads over boysens.

[Stevo17]

i have ditched a couple of sets of Boyesens and had better low down response from the OEM reeds.

[sa63]

reeds normally only effect bottom end performance, unless they are completely restricting flow. A 500 auto uses a MJ of around 380 -400 depending on if it is a 38 or 40 mm carb- ?cant see why a manual would be much different so   it seems you are running a very small main.are you at altitude. timing? air leak?

[PEZBerq]

Recommended jetting for 500AE's as supplied by Paul Rooney is

38mm carb: Slide 2.5 - 3.0, pilot 50 - 55, needle jet R2, needle 6DH3, main 400, float level 17mm - 19mm

40mm carb: Slide 2.5, pilot 55- 65, needle jet AA0, needle 7DH3, main 370 - 380, float level 19mm

Try changing the pilot jet first. My experience with going to Boyensens is on my 82 430XC is I had to go to a smaller pilot and main to get the bike to run well at small throttle opening. My 500 AE runs Boyensens and behaves well on the 38mm carb setting listed above at sea level.
 Good luck

[PEZBerq]

Mixed up the 38 and 40 specs but have fixed it above now so it it reads correct. Dyslexia rules KO

[subarumy98]

@Boots
What is your altitude ?
Water pumper or air-cooled ?

My air 500 is doing well on 45 pilot and 330 main at 1500m, BUT, the bowl is still emptying faster than I can fill it.
Float height already at the top level (17mm), any more and it will start pissing out at rest..

Honestly, I am still gettig my head around the jetting differences between 430, 500, 38mm and 40mm.

T

[subarumy98]

@Boots:
I got these from one of the guys on the Vintage-Left-Kickers site in the US.

https://skydrive.live.com/?cid=148d323a15ea1222&sc=photos&id=148D323A15EA1222%21181

 

[Barclay]

Running the bike at sea level ,she has a 40mm .and its a air cooled bike
We stepped up the jets to 420 main and checked the bowl level .
The bark up the top is bigger again .still takes a fair twist to get the engine to respond .
played around with the needle it had little effect on the throttle response .
still starts good ,no over run when you close the throttle .plug has good colour
Im starting to think reeds ,I do beleive the original two stagers were half the thickness of the boysens
cheers Boots

[Tossa]

HVA 500 -83 Mikuni VM 40 340 MJ, 45 PJ, AA-5 NJ, 7DH3 Needle, 2.0 Slide  Husqvarna recom.

or 350 MJ, 40 PJ, AA-0 NJ 7DH3 Needle, 2.5 Slide

[subarumy98]

Where is your air-screw at ?
Will post mine when back - that made big difference off-idle. for me, and cleaned up the midrange too.

Will post vid of current performance asap.