Mikuni round slide tuning baseline

Recently there was a Mikuni carb setup for a SP 1000 on ebay. I bid, but didn't win. I contacted the seller (Steve Braun), and asked if he would share the jetting information he learned in setting them up.

These carbs are available from pro-flo.com for $90 new, but without a baseline, you could easily spend that much buying tuning parts to get this close. He sent me the following info (with selected edits by me).

Here are the particulars for the Mikuni setup for the SP 1000.

• VM32 round slides
• 2.5 Cutaways
• 159P0 needle barrels (I think he means atomizers or needle jets here)
• 6DH3 needles clipped at the middle position
• 170 main jets
• 35 pilots
• 2.0 air jets

Some notes:

• The SP1000 was completely stock.
• Both intake manifolds are MG# 14115002 (Right Side). The left carb won't fit with stock left manifold, the carb hits the motor.
• The intake manifolds should be blended on the inside to match the carb opening.
• The air cleaners are K&N RU-1730.
• The installation fits very neatly if the battery is not oversized. I used a sealed Interstate unit: Y60-N24AL-B
• The carburetors came from Stan Smith at Rocky Point Cycle 937-376-9792

There are occasionally posts by members asking for information about jetting for Mikuni carburettors. I've posted the baseline I was working from in response before.

However my set up has benefitted from the expert attention of a local outfit (Turbopacs, Gateshead) whose carb expert happens to know a fair bit about Ducati and Guzzi set ups having owned a LM1 and still has his 1980 Ducati 900SS.

I wish I'd have gone to these people when I first switched to these carbs 9 years ago (can it really be that long?!!), would have saved me a lot of fruitless fiddling about. He's made numerous changes, bigger pilot, smaller main, different atomiser, adjusted floats, reset balance, and run a dyno test. Although I wasn't unhappy before, the bike feels a lot happier now; running somewhat leaner and altogether feels right. Money well spent.

So I thought I should update my previous post with the revised settings which I'm confident would be a good start for a T3 (950) standard cam and heads, fitted with Mikuni VM32s. When I picked the bike up from Turbopacs it was suggested that I might like to try 175 in the main jets and supplied these as it's a simple swap and my labour is much cheaper than his.