Hi everyone,
I have a general question more for the tuners out there. I am going to buy a replacement mikuni BN40i carb for 1998 Sportster 1800 w/717. I know its a boat but the drive train is the same and more people are in the Ski section. So I know the boat is bigger and heavier buy why are the needle/seat a different size? The jetting is almost identical 70 low and 167.5 high and 1.5 needle. The book calls for 72.5 and 167.5 high w/2.0 needle. Popoffs are both in the same range.
I would just like to know the difference the taller or shorter needle makes? Maybe for emissions?
I have 2001 GTI w/717 and I bought the same carb as I am going to for my 98 boat and did I nothing to setup and it works great on my ski even though an 2001 has different tuning setup. The factory low is 75, 167.5 high and 2.0 needle for 2001 GTI but replacement come with 70 low, 167.7 high, 1.5 needle bolt starts up works great.
So what is the difference in the setups? I know the ski's the 98 GTi pretty much same as and 2001 just pump might be different. Everything else same.
I have a general question more for the tuners out there. I am going to buy a replacement mikuni BN40i carb for 1998 Sportster 1800 w/717. I know its a boat but the drive train is the same and more people are in the Ski section. So I know the boat is bigger and heavier buy why are the needle/seat a different size? The jetting is almost identical 70 low and 167.5 high and 1.5 needle. The book calls for 72.5 and 167.5 high w/2.0 needle. Popoffs are both in the same range.
I would just like to know the difference the taller or shorter needle makes? Maybe for emissions?
I have 2001 GTI w/717 and I bought the same carb as I am going to for my 98 boat and did I nothing to setup and it works great on my ski even though an 2001 has different tuning setup. The factory low is 75, 167.5 high and 2.0 needle for 2001 GTI but replacement come with 70 low, 167.7 high, 1.5 needle bolt starts up works great.
So what is the difference in the setups? I know the ski's the 98 GTi pretty much same as and 2001 just pump might be different. Everything else same.
