batman wrote on 02/10/18 at 14:07:07:


I read it Batzy! I read It !  I removed the white spacer and left it with just the 2 lil washers. About to go test it now...

chris ,cheer up we all goof ,I had you at 9000ft and you are at 90 how's that for goof! Does your face look like this? then it's all good.

Chris ,three washers are usually used for elevations above 1000ft ,your close to sea level that's why I said two. Three might have you running to lean, but you could try,  and just check your plug. I'm thinking your mpg should jump to at least low to mid 40's.

Norm , the fact that Chris was running oversize main jet ,but his plug was showing lean ,made me suspect. he also said he was running speeds of about 55-60 ,this is mid range  (1/4-3/4 throttle) and controlled by the needle jet, jet needle,(lean) not the main(3/4-WOT) he had to have been running past 3/4 throttle to achieve 60 mph thus is poor mpg of 28.34.(rich because of the large main)

It was too dang cold to really go ride today but I did swap the filters back and forth a couple of times and it seriously does not like that big free flowing cone filter! It does exactly the same thing every time I put it on there. It seems to just refuse to operate the slide at all with the cone...

I could ask a little more of it with the pancake filter higher up in the RPM range but I will wait until the full 1500 mile break in completion to start trying to fine tune it too much.

If it's not too nasty I will ride tomorrow and see if efficiency has improved.

justin_o_guy2 wrote on 02/11/18 at 21:44:35:


Back up a little in the thread where I started talking about the addition of the big cone air filter...

I currently have it plumbed in with:
  Stock carb-airbox boot to a pvc 90* street with about a 3.5" nipple of pipe hanging down the backside of the battery. The air filter attaches to the end of the nipple hanging down.
There are no obstructions. Quite the opposite, I think... is occurring.
The cone filer flows too freely, and allows for no build up of air pressure at the rear top edge of the carb mouth. The port on the top side center of the mouth of the carburetor controls the slide diaphragm.

It's freaking cold outside this morning... but mostly dry and not too windy. I am going to bundle up and make the commute on it. Keeping the fingers crossed the efficiency improves!

My engine is modified a bit, has a Stage 1 cam, Wiseco piston and the first year after the engine build I ran a stock carb and a Dyna muffler.  I used an oxygen sensor to jet the carb - I ended up with a #150 main, #50 pilot and 2 washers.

While being gentle on the new piston I regularly got 62 mpg - this was all back road riding between 40-50 mph.  As the break in period ended and I started to ride at normal speeds, mileage dropped to somewhere around 55 mpg. (I don't ride 70 - 75 mph highway speeds long enough to know what kind of mileage I get at speed).  I can think of only 1 time my mileage ever dropped into the 40's - and I was down in the mountains riding very aggressively around the corners and accelerating on the straight sections.......having a wonderful time!

If you aren't getting up into the 50 mpg range - something is wrong with your setup.