Re: Mikuni HSR42 and breather system.
OK, I found a manual for your kit online....
http://www.mikuni.com/pdf/tkmanual012302.PDF
You are trying to fit Mikuni breather kit KHS 020?
**IF YOU HAVE THE ORIGINAL MOTOR**
Simple question: up until now do the rocker box bolts on your bike purely HOLD the air cleaner assembly on?
If the answer is YES (and I bet it is), forget about the Mikuni breather kit. It does not apply to your bike.
In fact, the instructions state it fits 1993-1999, but I believe many late 1992 bikes could use them as well
(If your bike was a late-type head breather ...and I am sure it is NOT.. with stock carb it would have a short L-shaped section of ''chrome piping'' from each rocker box bolthole to the air cleaner assembly, feeding muck into mix for burn-off. Mikuni do a slightly different version as you will see in the sheet.)
If you read the online instructions (above) you will see there at the very top of page 3 (TK-3) is a special dispensation for 1992 Big Twins: the ones that have the ''late'' rocker box boltholes but are still crankcase breather bikes just slightly bigger bolts.
You haven't really got the wrong kit, you've just got a bit extra you don't need. Should be able to use your existing bolts, but if not the specs are there for you to take to fastener shop.
Of course, you will need to use their other little Z-brackets and stuff as per directions.
BTW, the crankcase breather line does not go to oil tank. Stock, it went into air cleaner. Not a good move. Just route it to frame rail or mount on a bolt somewhere (brake pedal assembly, exhaust pipe support, etc) and place one of those little ?6 filters on the end. Look at any 84-92 Evo, you'll see.
***IF YOUR BIKE NOW HAS A BRAND NEW CRATE EVO WITH HEAD BREATHER ROCKER BOXES****
Follow the instructions as for 93-99 bike. USE the breather kit.
Hope this helps. Pretty tricky scenario!