Mikuni Jet type for 77 gs750?

[pasteurized]

As I can gather, my bike has VM26 carbs on it (correct?). What type of main jets then should I be purchasing? Bike Bandit shows that I should be getting the large hex type. Is that correct? Also, the sizing is different than I expected. From what I have been told here, my bike should have come with 102.5 mains. The large hex mains on BikeBandit are measured in larger, whole numbers.

Here's what BikeBandit shows:

http://www.bikebandit.com/partsbandit/productlist~section_dept_id~338701~terrain_dept_id~339911~cat_dept_id~811772~product_dept_id~811774~selection_Path~3.asp

Any hints?

[pasteurized]

I'm really hoping someone can help me out here. I have had suggestions to step up a full size to a 107.5 but it looks like the type of carbs I have take big hex main jets that are sized 50 thru 200 (increments of 5). What the heck do I have then, if mine are supposed to have 102.5 stock?

[earlfor]

You have the hex head, screw in Mikuni main jets. Full sizes are every 5, so that would be 90, 95, 100, 105,110, 115, etc etc. Half steps are 2.5 (and are a stock size also), so 97.5, 102.5, 107.5, etc etc are stock half steps.
Your bike uses 102.5 mikuni hex head mains. I am 101% positive. :-)

Do not increase the jet size if you are using a stock exhaust system and airbox/filter. It will run like crap and foul plugs faster than you can change them. Been there, done that.

Earl

I'm really hoping someone can help me out here. I have had suggestions to step up a full size to a 107.5 but it looks like the type of carbs I have take big hex main jets that are sized 50 thru 200 (increments of 5). What the heck do I have then, if mine are supposed to have 102.5 stock?

[pasteurized]

Thanks for the heads up Earlfor! I guess it was the lack of ability to find these jets for purchase in 1/2 sizes that was really throwing me off. Hopefully the jets I just ordered will do the trick :-)

Thanks again

[KW]

The 1977 GS750(DB) has 100 mains as standard. The C, EC, N & EN has 102.5