Carb Rebuild

[ianjb]

I am rebuilding a carb for a CT70 KO and i have a few questions.
First off how do I clean/polish the brass components?
Where can I get another drain plug screw?
Can I take the choke out and can I get the piece that is missing from it?
Is there anything else I can take out?
And finally how do I get the carb to look like the original finish?

Here are some pictures. I was going to buy this *CT70 KO THRU 1977 CARB PACKING SET (205K) to replace all the bad gaskets. Also the petcock has a metal washer type thing and it is warped, pushing the switch out causing a leak, thats what I think could there be another reason?

 

[snooter]

you can polish the brass with any good polishing compound..i dont see the point though..week later it will be tarnished again...ive never seen any keihan carb that i would consider to have "finish" they all were bare metal..you can clean that any way you want i guess..dr atv or others should have all the parts you need..if not polish em up..i have never seen a choke leak on a keihan..on a mikuni its a different story..so i dunno what the hell could be going on with the keihan choke...this week i have no love for the keihan..next week the mikuni will be on my shit list..luckily both are great carbs and dial in easily..good luck..

 

[ianjb]

Well the petcock is leaking and the coke is missing a piece do you know where I could get a replacement?

 

[tom0762]

the metal washer on the petcock is not warped, that's what they appear to look like when (new) also!

 

[ianjb]

So what else could make this area leak, bad gaskets?

 

[jdgmbi1]

So what else could make this area leak, bad gaskets?

Could be your float or needle.

 

[snooter]

ok i see the problem..replace the bent washer as you say and get a new rubber gasket..however if the surface is pitted from use there is very little that can be done...leaking petcocks i have found are always pitted and at least with my skill and judgement they cannot be repaired..i have tried and finally bought new...its just use over the years that causes the sealing surface to pit and wear and well not much you can do...hope this at least helps..best bet search ebay and try to find a better carb

 

[Backinthedays]

Here is a picture of a carb I just did. The picture doesn't show it to well, but I soda blasted it and it looks like a brand new carb in person. Even the brass looks new. Just be sure to clean it good and then clean it again!

 

[ianjb]

So this is about as clean as the shell is going to get, I mean like thats the color?

 

[Ayers Garage]

I just finished mine a couple of days ago. This is soaked in old school Berryman ChemDip then rinsed and soaked in Pine Sol for a few days then lightly bead blasted. Clean thoroughly after any blasting.

Before


After


As far as the petcock leaking and it's sealing surface, no need to replace it, just run it over a fine tooth file to machine it back smooth and remove the pits. It only takes a minute or two.`Combine that with a new rubber underneath it and the wavy washer holding tension on it and you should be good to go for another 40 years.

 

[Backinthedays]

So this is about as clean as the shell is going to get, I mean like thats the color?

The picture really makes this one look darker than it is. It looks really good in person. It might not be the exact color as it was brand new but it would be hard to tell. I have polished one before but I don't think it looks as original.

 

[jdgmbi1]

I just finished mine a couple of days ago. This is soaked in old school Berryman ChemDip then rinsed and soaked in Pine Sol for a few days then lightly bead blasted. Clean thoroughly after any blasting.

Before


After


As far as the petcock leaking and it's sealing surface, no need to replace it, just run it over a fine tooth file to machine it back smooth and remove the pits. It only takes a minute or two.`Combine that with a new rubber underneath it and the wavy washer holding tension on it and you should be good to go for another 40 years.

So, where would Old School Berryman Chem Dip be found?

 

[Ayers Garage]

Any auto parts store. I got my last gallon at O Reilly Auto Parts. It runs about 20 dollars, but is reusable indefinitely.

 

[Backinthedays]

So the ol pine sol work out pretty good? That carb looks nice. Makes me want to redo mine. I am going to try to take a better picture of mine. The picture I have doesn't give it justice. Might not be as shinny as the one in your picture but it looks nice. After soda blasting it I soaked it in a gallon of Gunk carb cleaner using a vibrating table.

 

[ianjb]

That thing looks great you guys have great looking carbs haha. If you don't bead or media blast it does it make that much of a difference?