'83 750 Kat carb rebuild

[versicat]

Hey Gang,

Well... I went ahead and got a battery and tried to fire up the Kat today. Simply putting gas in the tank = massive fuel leaks from the carbs. Figure I'd better go through them first and rebuild 'em.

Questions:

a. best source for rebuild kit? Seem to be plenty on eBay for like $90, but thought I'd ask y'all.

b. they seem to have some type of vacuum activated slides. Not terribly familiar with this system, having only worked on the old school cable-pulls-the-slide type carbs. Do I need to fiddle with the top of these carbs? What's the scoop?

c. these carbs are painted black. Are stock carbs black? They look like shit. I'd prefer bare aluminum. Any suggestions for paint removal? I'm thinking they'll need to be bead blasted or vapor blasted or something if they are going to look nice. I mean, with all the nooks and crannies, how in the heck else could I take off all the paint? Anyone ever polish these things? Will they hold a polish?

Thanks in advance!!!

Peace,

- Adam

[sixdog]

Hey Adam....I have had good luck with Ebay kits. As far as the slides , yes I would recommend taking those out and cleaning the slide area as well as taking a look at the needles. The paint....wouldn't be able to help you there.

Good luck brother!

[versicat]

Hey Adam....I have had good luck with Ebay kits. As far as the slides , yes I would recommend taking those out and cleaning the slide area as well as taking a look at the needles. The paint....wouldn't be able to help you there.

Good luck brother!

Cool, thanks. Is there some type of rubber diaphragm that I need to be careful of when taking the tops off those carbs? Any recommendations? Peace

[Suzuki_dog]

Hey Gang,

Well... I went ahead and got a battery and tried to fire up the Kat today. Simply putting gas in the tank = massive fuel leaks from the carbs. Figure I'd better go through them first and rebuild 'em.

Questions:

a. best source for rebuild kit? Seem to be plenty on eBay for like $90, but thought I'd ask y'all.

b. they seem to have some type of vacuum activated slides. Not terribly familiar with this system, having only worked on the old school cable-pulls-the-slide type carbs. Do I need to fiddle with the top of these carbs? What's the scoop?

c. these carbs are painted black. Are stock carbs black? They look like shit. I'd prefer bare aluminum. Any suggestions for paint removal? I'm thinking they'll need to be bead blasted or vapor blasted or something if they are going to look nice. I mean, with all the nooks and crannies, how in the heck else could I take off all the paint? Anyone ever polish these things? Will they hold a polish?

Thanks in advance!!!

Peace,

- Adam

Adam,

The '83 carbs were black. The best and least damaging way to remove the black is to have the carbs vapor blasted. If you can't find someone locally, I know a guy here in Indiana, but that would mean not having your carbs for a period of time. Vapor blasting looks very good when done correctly, probably no need for polish.

Carbs are vacuum activated, make sure the vacuum tube from the petcock is clear and not kinked, also. Get them cleaned up and rebuilt, they should work fine, I've never had any issues with mine.

[sixdog]

Joe's advice is perfect on the vapor blasting. The slides operate with a vacuum diaphragm. Remove the top of the carb and carefully remove the diaphragm ( rubber and slide ) from carb very gingerly.

[Suzuki_dog]

A couple of (bad) photos of vapor blasting. The first is before, the second after. He "blasted" the part for about 20 seconds.... He also had a carb that he had just done, along with it's mate, the blasted one was near perfect. Vapor blasting does not hurt any rubber or plastic parts, either.

[versicat]

A couple of (bad) photos of vapor blasting. The first is before, the second after. He "blasted" the part for about 20 seconds.... He also had a carb that he had just done, along with it's mate, the blasted one was near perfect. Vapor blasting does not hurt any rubber or plastic parts, either.

Cool. I heard about vapor blasting, and even found a vapor blaster on Craigslist (thought I'd just buy one and pay it off by doing a bit of a side biz; alas, was too expensive).

That is exactly what I need.

[Suzuki_dog]

Cool. I heard about vapor blasting, and even found a vapor blaster on Craigslist (thought I'd just buy one and pay it off by doing a bit of a side biz; alas, was too expensive).

That is exactly what I need.

I think he paid $3500.00 for his? Plus chemicals...

[versicat]

I think he paid $3500.00 for his? Plus chemicals...

That seems expensive - I could buy a vapor blaster and compressor for that. Hmmmm...

[sixdog]

A good friend of mine from the CBX forum has a shop in Tucson Arizona. He does vapor blasting. Give him a call, tell him Mario sent you and he will probably give you a quote.

https://www.restocycle.com/

[Frazer]

Carb rebuild

Hi Adam,
Hopefully you rebuilt your carbs but if you didnt I use and recommend Old school carbs
IN san Jose CA
As the name suggests this is all they do.They have all the factory mikuni tools and are pretty well known for there work on CBX 'S including Ian Fosters bikes and bikes that show at the Quail gathering.
He rebuilt my 81 Katana 1000 slide carbs to perfection after it had sat for 20 years when a local
( so cal ) katana "expert " said they were junk.
My Katana is a U K Homologation bike with the factory snoothbores so I wanted them restored
If you go this route be patient they take there sweet ass time but the end result was amazing
All o rings gaskets and seals were replaced new screws and the choke levers re plated
Right out of the box it fired up like new ,Old school has the factory specs for set up.
It pulls like a train, rides like it did when it was new.
Cant beat that.

[sixdog]

Fazer is on the money....I own two 1979 CBX's and when I need a good carb rebuild I use Mike Nixon's shop , http://www.motorcycleproject.com/....

Basically bolt on and hit the starter button and it runs like new....