Thanks for the pointers to the pilot screw. I've found it in my service manual (but not yet on the machine itself!). Backing it out a bit to richen up the idle mixture makes perfect sense.

The manual says the pilot screw is protected by a brass cover that is not supposed to be removed. Figures that the one adjustment *I* need to use is the "protected" one. Anyway, the factory setting is 2 1/2 turns out from seated, then they stick a brass cover over it and tell you to leave it alone. Delightful.

Any worries about removing that cover? I presume I just stick something in its center hole and pull it out?

 

You'll probably have to take the carb out to do it but you can drill a small hole in the brass cap and start a sheet metal screw in it and pull the cap right off, there was a service bullitin out about this in 02 I believe, do a search on here you should find it. If you put a quiet core in your muffler it will be quieter and put the 800 header on for more gains.

 

Right on the money...we drill out those brass covers on Harleys all the time, for a similar reason. Wrap tape on the drill bit so you don't drill too far and jam the bit end against the screw, cranking it tightly into the seat and damaging it.

 

Forgive my ignorance... what is a "quiet core" and the "header" from the SP800? This muffler has the standard fiberglass wrap design with a big open area in the center - is the "core" something you put in that center area? And won't that decrease performance? It's been my experience that the quieter the muffler, the more restrictive. If I'm going that way I could just put the stock muffler back on [grin].

Does "header" mean the front exhaust pipe?

Sorry for all the questions, I'm just trying to learn. Thanks!

 

While researching carb adjustment, I ran across the following paragraph on a Wikipedia article. This sounds EXACTLY like what is happening on my machine...

>>The greater inertia of liquid gasoline, compared to air, means that if the throttle is suddenly opened, the airflow will increase more rapidly than the fuel flow, causing a temporary "lean" condition which causes the engine to "stumble" under acceleration (the opposite of what is normally intended when the throttle is opened). This is remedied by the use of a small mechanical pump, usually either a plunger or diaphragm type actuated by the throttle linkage, which propels a small amount of gasoline through a jet, wherefrom it is injected into the carburetor throat. This extra shot of fuel counteracts the transient lean condition on throttle tip-in. Most accelerator pumps are adjustable for volume and/or duration by some means. Eventually the seals around the moving parts of the pump wear such that pump output is reduced; this reduction of the accelerator pump shot causes stumbling under acceleration until the seals on the pump are renewed.<<

I haven't seen any reference to an "accelerator pump" on the SP700's Mikuni carb, so I don't know if this is applicable to my machine or not. The description sure sounds applicable, though. Anyone know about this?

Thanks!

 

The 700 uses a CV carb and they don't have an accelerator pump.

 

I'd heard that CV's don't use accelerator pumps, but I've also seen some Mikuni CV carbs intended for Harley-Davidson motorcycles that DO have accelerator pumps on them so I don't know what the correct answer is.

The carb on the SP700 is a Mikuni BST34. Googling about hasn't revealed whether it has an accelerator pump or not.

 

I am running mine with 6 discs. Some of my buddies are running 8 & 9 discs. I would try adding/taking from the discs b4 messing w/carb.adding<u>adding</u>