Are all bored TB's created equal?

[Kenny]

Most of you already know the answer. This is a little info on what has been called the nicest bored TB on the market, which is simply false marketing to get your money.

Here is the evidence as supplied by one of my competitors:
Notice the out of round condition of the bore and the poor fitting throttle plate illustrated by the backlit plate that is completely closed without the throttle housing. This TB casting was clamped too tightly during machining and has some pretty serious bore distortion, meaning the throttle plate had to have extra clearance to keep from binding. Idle problems were the result.



More evidence of core distortion as you can see the final pass did not make a straight cut all the way around the bore. This is easy enough for me to fix, because this TB did not measure 47mm (+3) anywhere. It was between 46.7 and 46.89 depending on how you clocked the mic. There was .008-.009" plate to bore clearance, which should have been strictly held to a much tighter number. The throttle plate was not a precision machined piece, it looks as if it is a punched piece by the look of the rough striations around the edge




Check out the super hard stainless fasteners they were not bradded into place and used no locking compound of any kind. They were surprisingly easy to get loose, and would spell certain death for an engine if they came loose. This is the third "competitors" throttle body (since a couple of guys are selling the same one) that I have had to repair lately, and by no means an isolated incident. The good thing is that all I had to do to repair them is bore them to an actual +3, install a precision machined plate held to .004" and install "soft" screws with a good thread locker, or in layman's terms, redo everything that they already paid for!



This TB not only had very poor tolerances, but the throttle shaft was warped from machining as well. This is gonna lead to shaft and bore wear that will be a problem down the road. Anyone that has bought one of these needs to get thread locker on the screws at the very minimum. These screws are so hard that you cannot brad them into place without bending the throttle shaft. If anyone needs help with fixing theirs, please feel free to contact me.

[Colorado700R]

So the symptoms of a problem like this is poor idle?  any other effects?

[Kenny]

So the symptoms of a problem like this is poor idle?  any other effects?

Sometimes there is a poor idle, that may or may not be correctable. The worst danger shows no symptoms until it happens, and that would be dropping one of those hard screws and destroying your motor. If someone has one of these, they should immediately check it and at the very least, get some loctite on those screws. The rest will just be an annoyance

[txredxj]

crap i missed this thread. i have idle problems. thought kenny did mine but now i wonder. so im guessing if it has soft screws its ok?