Feeler Gauge and Slide Clearance

I was trying to figure out if I needed new slides when I realized that I didn't even have a feeler gauge that was small enough to measure the clearance between the slide and the body. Mine only goes down to 0.01 and I was reading that the original tolerance was 0.0035 and that anything over 0.007 was too much. If I'm picking up a new gauge set are there recommendations about what type and range of gauges would serve me best for working on a Norton? Also, how are you supposed to measure the clearance between two round objects with a flat blade?

Here are what my slides currently look like - they are original to the bike and have 13K miles on them.

Amal slides and bodies ( original) are typically worn out anywhere around 10,000 kms. Lousy idle , rich plugs , etc. until the really bad thing happens , the slides fracture from the vibrations and rattlings. Straight into your motor. Time to $pend on new. :wink:

Inside and outside calipers may help you measure. the normal way to check amal slide clearance is by moving the slide in the bore with no cable or needle. If it rattles around at certain heights and not others, the carb bodies could also be ovaled out.

Simply put just reach in with thumb and forefinger and grab the slide in the bore and try to wiggle it back and forth and side to side. Sloppy at all ? Time to replace. :cry:

IMHO, they look pretty good, If they are moving with out snagging in the carb bodies I would run it up and test on those.
There is always something else to buy :wink:

Fine feeler gauges will easily bend enough to follow the edge of your slides. Original clearance is about 0.004 inches ( four thou) I have heard of people going down to 0.002" when getting them re-sleeved. The 32mm carbs have less material supporting the slide than the 30mm ones and IMHO the 30mm carbs run better on the idle circuit.

Thanks for the tips and advice. I think I will go with these for now and pick up some fine gauges. The slides are always easy to change out later if needed. Instead I'll focus my limited cash on things that are harder to change out once everything is back together.

Your carb bodies look "sleeved" to my eye... I wouldn't assume they are bad at 13,000 miles. That being said, if they are sticky, clean the hell out of them, polish them with 0000 steel wool, blow them off good with compressed air, and reassemble.

I've had a sticky carb that I removed from the bike and adjusted the fit of the inner and outter body with 1000 grit wet or dry sandpaper. All it took was a few strokes in the spots where the high spots were buffed to a shine by contact with the inner body and the slide moved fine. People will tell you to throw them away, change to mikuni, or buy new amal premier carbs... Certainly a lot of people give up on using the old amals because they are not as easy to tune, set up, or maintain. My carbs are sleeved original 930 amals that work fine. It has been a battle learning about them over the years and getting them right. I've experimented with different jets, needle positions and ignition timing, and the reccommended settings work best for a stock engine, so save yourself some guess work and just use the recommended settings...

Set them up, see how they work, go from there...

Those slides are not sleeved but do look in good condition. Most people change the slides and leave the bodies. Despite your slides looking good, 5 minutes with a set of feeler gauges will tell you how much the bodies are worn.