i'm looking for the company that sells a kit to put bushings in the base plate
for the throttle shafts, fixed a few so long ago can't remember ,came with
drill,8 bushings, reamer. i did the finish hone i have 5 to do ,any help??

 

Contact one of 3. Carb Shop, Jet Performace and Sean Murphy induciton all in california and all have web sites.

 

none of these 3 are it , somebody else has to have done this to, done right
it's a one time fix...

 

try "carbs -r- us"

 

thanks, checkin' all info.. may need to start up part time repair after set-up
costs, but oh well i love it

 

Here's one...
http://www.jetchip.com/fuel/bushkit.cfm

They (automotive machine tool suppliers) also sell "professional grade" kits which include additional tooling for broaching out the bushing after installation. I use special order flex hones for that job instead of the ball broaches.

I have had my "professional" kit for 25 years.

If you buy a kit that provides 3 inch lengths of bushing material and a "cut-off" tool, do not use the tool... it messes up the new bushing and gives a false finish ID reading.
In this case, measure & pre-cut the bushing before installation. Make sure the bushing material does not invade the space of the throttle discs when the throttle is closed. This happens when the bushing is too long for the bore, or is pressed too far into the bore.

I use a dremel to "chamfer" the bushing ends on occasion if I think the cut ID is messy.

If the shaft is excessively worn, the new bushing will help, but may not solve the problem entirely. This happens when people install extra heavy throttle return springs in an attempt to solve the worn shaft/throttle body problem. This is very common on Holleys, and the aftermarket throttle shafts are not always the correct OD.... so you are back at square one even after you install a bushing. The replacement TriPower throttle shafts currently being sold are a case in point... they are undersize. I mic'd an original and a replacement... they are off by several thousandths.

 

thanks tom454 do you use "loctite" on bushings before pressing them in, the
way i did it yrs ago was, drill base out (just under bushing o.d.) drop of loc.
press in (let set) lightiy ran reamer, then used a dremel to hone to size, (each
thottle shaft) is this the way you do it?

 

I've never used loctite... and never had a bushing fail.

If the reamer and bushing are designed specifically for the job, the bore will be quite tight around the bushing. If you use a "generic" reamer... and a generic bushing... then all bets are off. I have generic tools, but I do not use them for carb repair. I can remember only a few carbs where the bushing was too tight on the shaft.... and I've done quite a few.

It certainly will not hurt to use loctite though.

I DO use loctite (medium strength) on the throttle disc screws... the replacement screws are typically the wrong design and/or material, and I prefer to re-use the originals. The trick is to have a lot of patience and a steady hand grinding the screws for removal.... don't take off too much, don't take off too little. If the threads are "iffy", then I do use new screws. The dremel (or other tool) has a tendency to "grab" during this grinding step, and it will do instant irreversible damage to the throttle body, the shaft, or the discs. I put masking tape around the work area to minimize the probability of damage.

In most cases, since I use the specified (piloted) reamer and bushings, the ID of the bushing requires zero honing or additional reaming. If the shaft does end up too tight, I use "flex" hones... they do come in the small sizes necessary for this work. You have to order them from a "real" machinists supply house. They are used for honing valve guides to final size, and come in SAE as well as metric sizes, and various grits. I do not use a dremel driver with these flex hones... they work extremely quickly and remove a lot of material very fast... I use a variable speed drill and run at slow rpm, re-measuring between every 2 passes with the hone. The dremel is too light weight, and tends to "over-speed" without warning because it has low torque. The hand drill has a "flywheel" effect (simply due to the weight of the armature) and the gearing helps to avoid over-honing.

In some cases, for no obvious reason, the "split" bushings will be a little tight on the shaft, but ONLY at the ends. The bushing driver may contribute to this problem (mushrooming). I use a press... not a hammer. This binding can fool you into thinking that the entire bushing is way too tight on the shaft... and if you then hone the bushing, the end result is a loose bushing/shaft combination. So you're back to square one. It takes a little experience and some good measuring equipment to determine if the problem is just at the end, or along the entire length of the bushing. In the case where it is only tight at the end(s), I use a dremel to remove a very small amount of metal from the outermost end of the bushing until the shaft goes in with no resistance.

I have small hole gages, ball gages, and plug gages that I use for cylinder head work, and digital micrometers that read in the millionths.

There is a trade-off on "snug" completed jobs. After a few weeks/miles of use, the shaft will loosen up as the high spots wear off and the shaft/bushing mate to each other. It's impossibe to predict how much "wear-in" will occur. I shoot for about .001 clearance, but have let them go when they were tighter than that, hoping for the best. It's a judgement call. If your clearance starts out at .002 or .003+, then it won't be long before the carb starts having problems again. I oil them & work the completed assembly for about 15 minutes manually to see how it is going... WD40 woks good because it carries away the sediment and lubricates at the same time. If it doesn't loosen up, I take it apart and touch it just a smidgen with a hone and try it again.

 

thanks Tom454, looks like i got lucky on the one's i did, i owe you one