Throttle slide question

Hi!

I'm doing a carb cleaning and complete overhaul on a -83 XJ550 (4v8-european). I've noticed a detail that I'll need your advice on...

Two of the throttle slides (the tubes on wich the diaphragms are fitted) are originals and the other two are aftermarket parts that were mounted some twelve years ago when the originals were worn out.

My question concerns the bottom of the slides where the needles comes out. On the originals there are two holes in the bottom. One just next to the needle and the other one,slightly wider, a bit further out towards the edge of the slide. On the aftermarket slides the holes for the screws that keeps the "needle mounting plate" inside the slide are drilled all the way through the slide bottom leaving two extra holes there. The holes are obviously plugged by the screws but since the screws aren't that long there are two 0.4 inch cavitys in the bottom of the aftermarket slides that aren't there on the originals. So... Is it possible that these holes will affect the carb function in any way? I figured that since the carbs are really sensitive I want to be 100% certain that this is kosher.

Hope you can make some sense of this, I'm sorry that I haven't got any pics.

-Felix

 

I had to read your description a couple of times to understand what you're talking about, but I think I do.

You're concerned that the "unfilled" threaded holes being open between the bottom of the slide and the ends of their screws (can't be 0.4", maybe .04"?) could somehow affect performance?

Good question. I can't see how it would, as long as the screws truly seal the holes; and the necessary, functional holes are the same as the original slides.

My only concern might be a significant difference in weight between the aftermarket and OE slide assemblies; do you have a way to accurately weigh them?

 

Hehe, yeah... I realise that it wasn't crystal clear, but you guessed right - that was my question! =)

I'm not at home with inches since I'm eroupean =) The depht of the holes are about 8mm and that gives 0.31" when I put it in a converter.

I'll have to get my hands on a way then!

Thank's for your answer!