Mixture screw adjustment ‘83 Aspy

kerryb · Aug 3, 2024

83 aspencade, 73k miles this is my touring bike so it tows my small camper and gets 42 mpg. I just finished a checkup of valves and carb synch. Everything is wonderful but one spark plug. #4 cylinder has a more whiteish coating on the electrode than the others which are a nice tan color. Can I richen the mixture with only an adjustment of the mixture screw? #4 was also the cylinder with a touch lower vacuum at idle, which I adjusted out with the linkage.
Appreciate the opinions. ( leaving on a trip monday morning.)

zman · Aug 4, 2024

Give it a try, I would go 1/2 check then anoth1/2 if it needs it just so you can ride without worry but really should burn evenly if they are all the same turns might have a partial clog but riding far may sort it out recheck on the road and re adjust if needed. Hopefully the lock on the screws have been cut off or aftermarket screws installed.

mcgovern61 · Aug 5, 2024

If you made it this far at 42 MPG, I would only consider a minor cleaning via adding 8 oz of ATF to a full tank of high octane gas to see if there might be some minor deposits. I have not done any work on an 1100 in quite some time now, but I only adjusted the mixture screws via the idle drop procedure.

kerryb · Aug 14, 2024

Thanks, I just got back from a 900 mile ride over 4 days. I got gas mileage of just a little better but have not made any adjustments yet. I’ll pull the plugs to confirm conditions first. It starts and runs so well, I don’t want to spoil it.

Nevrgonastopit · Aug 17, 2024

zman said:
Give it a try, I would go 1/2 check then anoth1/2 if it needs it just so you can ride without worry but really should burn evenly if they are all the same turns might have a partial clog but riding far may sort it out recheck on the road and re adjust if needed. Hopefully the lock on the screws have been cut off or aftermarket screws installed.

Is that turn clock or un-cĺock ways