Mikunis on an R100RS?

[Rapid Dog]

O.K,., been reading allover the web about which what where when what the f concerning which Mikuni's to use on my bike.
1981 R100RS, 40mm bings/38mm exhaust, stock airbox, Uni filter, dual plugged, otherwise bone stock.

So, I'm see TM38s (-85's and -86's) and VM38s.
Now tell me fellas, what's right for me?.........

[Major Softie]

So, I'm see TM38s (-85's and -86's) and VM38s.
Now tell me fellas, what's right for me?.........

Why?

This is not a specious question. Why you want the Mikuni's may be an important factor in what's right for you.

[vanzen]

O.K,., been reading allover the web about which what where when what the f concerning which Mikuni's to use on my bike.
1981 R100RS, 40mm bings/38mm exhaust, stock airbox, Uni filter, dual plugged, otherwise bone stock.

Given the engine: stock, large port / valve.
I'd be looking to keep the velocity up ...
and a 36 mm.
VM or TM - your choice.

BMW & Mikuni – read more here at ADV

[Rapid Dog]

,,I'm all over that thread Vanzen. Also sent you an e-mail about such...

[vanzen]

OK. seen you there ...

Back in the day, Mikuni kits were sold as "touring" or "performance" -
The touring kits included necessary hardware to connect to the stock air-tubes & air-box.
Without the kit, it's just a matter of simple plumbing.
Of course it can work ... the longer intake tract can be a torque +,
and a better alternative should it rain, too.

Be very wary of generic jetting recs -
Perhaps as a guideline so as to have a range of jets on hand for actual tuning ...
But paying attention to anything that starts with "1 jet size for custom 4 into 2 exhaust",
or " 2 jet sizes for individual filters" ...
Very likely will have you pissing in the wind.
There will be no shortcuts to getting it right - Tune for your engine.

[Rapid Dog]

A couple of these carb vendors (NIche/Rocky Point) sell VM32/34/36's jetted for an R100. But they don't sell 38's jetted for the R100. Got any idea why that is.
Is a 36 about as large as you want to go on an R100?

[Motorhead]

I'd do the 36mm in TM or VM myself, keep the mixes strong and better mixed with a smaller carb

I had a 1974 R90/6 with 36MM TM's and it ran Very Very Well

that bike could beat a stock R100s

[kutter]

Rapid Dog
Have you seen this site?

http://www.braigasen.com/Mikuni_jetting ... stroke.htm

[vanzen]

A couple of these carb vendors (NIche/Rocky Point) sell VM32/34/36's jetted for an R100. But they don't sell 38's jetted for the R100. Got any idea why that is.
Is a 36 about as large as you want to go on an R100?

BMW fitted 38 mm PHM Dells to the R90S.
Luftmeister, San Jose, etal, sold 38 mm TM Mikuni kits for the R100.
36 or 38 could work well –
Which of these will be the better choice for your engine
might depend upon performance that you hope to achieve.

Want a 38 mm TM Mikuni kit for an R100 ?

Contact Yves Faucher at Les Entreprises Montécristo, Quebec, Canada.

[Rapid Dog]

COOL...I'll give this some more thought. I'm just looking for some better throttle response, less lag. Not all out race stuff. I actually like the Bings, but after riding modern bikes for a while, I'd like a bit more 'repsonse' .
That Les Entreprises Montécristo, Quebec, Canada. linky never seems to work for me.