So what did I learn?

What a year. Long story short, we took my 21 year old stepson off a dangerous bike and gave him an old Jeep Cherokee to get around in. So now I have a 1982 Yamaha Maxim 650 that intermittently runs, won't idle under 4000 rpm, has cracked sidewalls on the tires and no brakes.
My gallery has a list of everything I have done to this bike.
I purchased a set of carbs from ebay last fall and cleaned and rebuilt them with extreme patience and precision. The carbs on the bike I had rebuilt, but always felt I could have done better, but I was in a rush for some reason to get the bike running. First rebuild I didn't to the fuel rails or shaft seals, 3 months later I had to.
I installed the new carbs, rechecked the valve clearances, did a running vacuum sync, then used the colortune plug to adjust the a/f mix, then reverified the vacuum sync.
What have I learned? The carbs are a work of fine precision and have very little tolerance for not being spot on.
Bike starts almost by just looking at the starter button, idles down whether it is cold or hot.
No hesitation off the line and the powerband just keeps going. I had a Kawasaki 1000 LTD back in the late 70’s and this bike seems just as fast and powerful. Well, at 56 it is all I need plus more, lol.
Seriously, if you are having carb /running problems, stop using sprays, additives, and witch oils. Take the carbs apart till there is nothing else to take apart. Be meticulous and precise on cleaning and rebuilding. Don’t think it is ok, make sure it is ok. Verify all jet #'s are the same and correct for your bike. Polish and clean with extreme dedication. There are absolutely no shortcuts. 30 years have played havoc on some of these bikes and a restoration can’t just be a can of carb cleaner, some seafoam and a blow from an air gun.
Big Fitz, Rick, Chacal, K-moe, Polock, Hogfiddles and many others have all agreed on one thing, spec is in spec and you have to be precise and really meticulous on rebuilding the carbs.
No shortcuts…..that is what I really learned…do it right the first time and then get to enjoy your bike.
Have a great summer ya’all!!

 

Bruce,
That is very inspiring.
Hopefully I shall also reap the same benefits.
Lord knows that I am certainly taking my time. :?
And meticulous is my middle name.
Biggest threat to me is seeing others out riding whilst my carbs are in pieces.

 

Stickied in my brain. Well stated, Bruce.

 

There you have it. Yet another voice speaking from experience.

As I've said way too many times, these carburetors reward precision. (And ruthlessly punish anything less.)

 

But, but that one guy said the YICS system dooms all these bikes to failure? I just don't know what to believe.

 

that's a bunch of hoo-ey. The YICS is basically a passage between the intake runners that allows the fuel charges between the intake runners to 'balance' themselves a little, as well as add some additional "swirl" to the charge. THe idea is that it will help increase the burn, making it burn more completely and efficiently.

The YICS block-off too separates each carb from the others so that you can dial the carbs in even more accurately.

However, PERSONALLY, (and I know others feel the same way.......it's often a discussion at carb clinics) I don't use a YICS tool..........yes, I DO have one, thank you very much----- I believe that with careful colortuning, and carbtuning/balancing, the intake stuff will be just fine.

Now, to add fuel to THAT fire, the YICS system came into being, and then disappeared too.........which seems to me to indicate that they decided it wasn't the 'big solution' that they thought it would be.

In short, no......the YICS system doesn't doom all these bikes to failure.

Dave Fox