Full Throttle Thanks to all the Great Gear-heads on this forum

[jonsmyth]

I did my diaphragms today- 3 were holy! Like holy crap, batman!

After my second tank of gas netted me only 30mpg, I got busy reading.

I jumped in and removed my diaphragms today. The first had no holes, and I was wondering if I had needed to buy the kit as recommended from Sirius Consolidated Inc. as advised by you guys here on 1st gen. posts. But the second, third and fourth cylinders all had multiple breaches. My slider jets did not have the white washer, but had multiple places on the body where you could move the cir-clip, and thus the mixture, up or down. As one post by member Bobcat mentioned his BMW had this feature, and you can lean it out by moving it up a notch. I did this to all the sliders, and I have not road tested it yet but it runs fine.

I'm wondering if someone put a set of old carbs on my 1987?

I look forward to adding a crankcase breather (tips , anyone?) like i read about here, and checking my mileage.

I have to say thanks to all that helped- especially "5bikes". I would not have had the courage to break into the carbs without the input and guidance of this group.

[SaltyDog]

The filter I used to replace the crankcase vent hose to the breather box I got on Ebay. It fit fine and has worked for over a month now. The seller has more of them listed, here is the item number for one he selling now , Item number:390090774044.

 

It costs $5.99 and the shipping is $5.99. I don't have any affiliation with the seller, I am just a satisfied customer. I installed mine on my 1983 Standard XVZ12. The only interference I encountered was one of the metal hard lines, I just used a socket extension to reach it and bent it slightly to clear the base of the new filter. Now I can remove the breather box easily and it goes back on without any trouble. So far I haven't seen any oil gather on the outside of the new filter and I know my crankcase will breathe clean unrestricted air.

[Dano]

Good go there, Jon! Now that you have those nasty diaphragms replaced, how about doing a synch and possibly a color tune on those bad boys? Fuel mileage should pick up, it'll run like a scared rabbit, and you won't be able to keep that grin off your face!

 

Dan

[jonsmyth]

I have a "Racepro" 4 barrel sync manometer? that a police detective lent me- but no clue how to tune them- going to you tube instructional school!

[5bikes]

Moving the circle clip towards the short end, away from the "pointy" end actually drops the needle further into the emulsion tube (needle jet) leaning the mixture therefore increasing gas mileage.

Moving the circle clip down towards to pointy end, raises the needle which richens the mixture and makes MPG lower.

It's easier to think about this if the carbs were not downdraft but more like most inline 4 cyl. engines with horizontal draft carbs. Needles point down, dropping them into the jet (tube) makes the taper larger (but just minutely), choking off gas. One clip position can make a large difference in driveablity and 2-5 mpg.

Same for removing the white spacer. If it's .1" thick, reduce it to .075" or .050" with small washers and your leaning. .050 is about 5-7 more mpg, .075 is about 3-4 more mpg.

BUT please do a plug check after doing this. Off white to tan, clean, or gray is OK. Very white is too lean.

Also do a search on "Improving Gas Mileage".