Carb question (newbie)

[cajun31]

I always disassemble everything, including splitting the carbs from the carb bank. If available, around you get the one gallon can version of Berryman's with the tray in it and put all the parts in the tray and let it all soak. Some folks will chime in and say the Berryman's will harm the rubber parts. The one gallon can version does not. Safe to let the parts soak. The heat trick worked for you. Another neat trick is that the float bowl screws and top cover screws fit the emulsion tube threads too and putting one of those screws in after you remove the main jet gives you more room and something to tap on to get the emulsion tubes out. Once you soak the carbs don't be afraid to clean them thoroughly with water then blow all the passages out with air. Compressor air is best if you have it. When you remove the pilot jet screws from the towers lightly seat each one making a note of how many turns on each one. That will be a good starting point after cleaning and reassembly. If you haven't already read the tech tip on bread tie bench synching. Also something to do after reassembly. Depending on the condition of the carbs it is also a good idea to replace all the shaft seals. The intake manifolds are also a source of problems with vacuum leaks. I am not talking about leaks in them and that is generally not a concern, they can look cracked but it is usually just surface based. The leaks occur where the manifolds meet the engine. A lot of companies sell gaskets that if installed break down and don't make a good seal. Get rid of the gaskets and use a good quality sealant such as yamabond and put a thin coat on the engine as well as the manifold. That will seal then against the engine. Vacuum leaks will cause all kinds of problems when synching the carbs. If you don't already have a good set of synch gauges you might want to consider getting a set. These old bikes have to be checked often as part of routine maintenance. Plenty of tips available here as well as good folks. Oh and pictures are worth a thousand words when asking for help. If parts are needed as you go along be sure to stick to original mikuni parts and stay away from aftermarket. Some of the parts in the aftermarket are usable but none of the jets that come with those kits are worth the pain they cause to make the work.

[MarkD]

All good points, guys. Especially the one Cajun31 about writing down the turns to back out the pilot jet screws. I just cleaned my carbs ( See my post about a cold cylinder), and reinstalled them accordingly. Tempt- DO NOT screw pilot jet screws too far, or you will incur the dreaded point break-off and buried tip of the point. The PO did this on mine when I bought it, and it was a pain to remove. Good luck. BTW, I cleaned mine 3 X to get them super clean.

[Tematt]

Thanks all - Very helpful and responsive group! These puppies gonna need 6x cleaning. I rack it up to it being better than pulling them back off 5 times. I do not think the previous owner had this serviced, couldn't imagine that in 43 years, but definitely a possibility..

[DEEBS11]

Carb gasket with O-rings

https://www.ebay.com/itm/352927647481

[DEEBS11]

Rubber manifolds. You can ditch the gaskets like Cajun31 said.

https://www.ebay.com/itm/361850795811

[DEEBS11]

Carbs seals. Qty 2. You will need a few sets to do your carb rack.

https://www.ebay.com/itm/291732072322

[DEEBS11]

The best carb tool on the planet (and I have used them all).

https://www.ebay.com/itm/222463312429

[DEEBS11]

This is my secret to cleaning carbs. Used on hundreds and hundreds of carb cleaning jobs from chainsaws and lawn mowers to antique BMW, Indian, and Harley restorations. It will not harm rubber. I use it with hot water. Much more powerful than Simple Green. Great for cleaning outside of engines too. Been using it since it was called "Castol Super Clean". About 30 years.

https://www.ebay.com/itm/16642201033...Bk9SR9z0nPuDYw

[Radioguylogs]

We're going to nickname Deebs "The Sourcerer".

[LAB3]

We're going to nickname Deebs "The Sourcerer".

Those of us that have been around awhile know that knock off parts are often more trouble than they're worth.

I've seen PLENTY of intake boots out there that go anywhere from $30 to well over $100 such as the ones deebs linked. My question is are the more expensive ones really worth the extra money? Georgefix has a great rep for selling decent quality parts on eBay and he also has boots that go for half that price so my question is, are they really worth spending the extra money on?

Same with diaphragms, there's cheap and more expensive ones. How do you know which ones are worth passing on and which are worth buying? Seems to me best ones are the ones that have been tested by someone who's actually bought and used them.

I've been putting off tearing into my carbs for far too long and more than likely will be doing that in the next month or two. Now I know that genuine Mikuni is the way to go but some things can be just as well accomplished with more affordable parts, right? After all it seems to me that a viton oring is still the better choice despite who's name is on the package.

[bikerphil]

My experience with the cheap carb intake boots is that the sync tube ports will come out when you try to pull the rubber cap off. It seems like the internal metal under the rubber is much thinner. You can actually see how flimsy they are when they get hot, you can see them pulsating with the suction of the piston intake strokes. A real bad idea using these too if you are running pod filters with nothing extra supporting the carbs.

IT seems like the decent quality ones, such as TourMax
are made in Japan, not China.

[DEEBS11]

As I have written many times, avoid the cheap Chinese parts (especially rubber parts). I always try to source Japanese or American manufactured parts. It's getting real tough these days.

[cajun31]

The best carb tool on the planet (and I have used them all).

https://www.ebay.com/itm/222463312429

Lot's of folks don't like the morgan carbtune's but I am one of those that give them a thumbs up. I also recommend and use the colortune. If you go that route these old bike like just the hint of orange instead of the blue recommended. Gunson Colortune See Through Spark Plug Kit (gunsonshop.com) thread size is 14mm and they are usually out of stock.

[Tematt]

bikerphil find me some carb diaphragms, i also see I got mixed jet sizes on the current carb from po, 3x 115, and 1 @ 120.. God bad eyes, but i think thats what they read. ugh... Sooo jets too? The kit I got came with a 110 and a 115, seems like I'll probably only use that kit for the gasket

[bikerphil]

I don't know who has the carb diaphrams, I was referring to the engine side intake boots...

https://www.ebay.com/itm/27269541451...Bk9SR6KKx7OEYw

Main Jets...

https://www.jetsrus.com/a_jets_by_ca...arge_round.htm