Desmog & Carb rejet --- Finally!

[Duct Tape]

Finally got around to it.  I pulled the carb bank today.  Desmogged and in the process of rebuilding and rejetting the carbs.  Have two of them done.  I knew the left bank didn't sound right.  It was backfiring and just overall gurgling a lot.  The number 2 cylinder carb spring was broken into three pieces.  I was considering ordering the I/S springs anyway.  Also, the pilot screw was only 1/4 turn out.  Hopefully will find time to finish a couple more tomorrow.  Also, plan to put on a 4 degree trigger wheel sometime this next week.

One question -- my jet kit recommends the needle setting at #3.  Do I count down from the top or up from the bottom?  It has five grooves, so it would make a difference. 

[R J]

5 grooves........

Set on # 3

Would make a difference.

It wouldn't make a difference when I went to school, but this new math sure do suck.

Start at the bottom slot as 1, next is 2, next is 3.
Start at the top slot as 1, next is 2, next is 3.

Same damn slot either way isn't it?

[Duct Tape]

Duh....brain fart.   QOTFU said I had to be getting high sniffing all that gasoline and carb cleaner.  I kept looking at it and thinking...if it had six grooves it wouldn't matter.  That's what an engineering degree does...makes you think about it too much and make it complicated.

[Patrick]

Do you know who owned this bike before you?? I'm wondering if it was one of us and if the pilots were adjusted using with a tachometer..Glad you figured out switch groove is which,, its fun to be our age isn't it??

[stevelp]

Finally got around to it.  I pulled the carb bank today.  Desmogged and in the process of rebuilding and rejetting the carbs.  Have two of them done.  I knew the left bank didn't sound right.  It was backfiring and just overall gurgling a lot.  The number 2 cylinder carb spring was broken into three pieces.  I was considering ordering the I/S springs anyway.  Also, the pilot screw was only 1/4 turn out.  Hopefully will find time to finish a couple more tomorrow.  Also, plan to put on a 4 degree trigger wheel sometime this next week.

One question -- my jet kit recommends the needle setting at #3.  Do I count down from the top or up from the bottom?  It has five grooves, so it would make a difference. 

I have had my carb bank on and off about four times.  Ran good each time I put it back on but I kept getting fuel leaks.  I am finally getting the picture that I need to rebuild all of the carbs,  I'm kind of thick and kept hopeing that each time I did something it would fix it.  No such luck.  Where did you get the carb rebuild kits and how much were they?  Also did you have a shop manual or did you do it by the seat of your pants?

[Patrick]

'Glad you figured out switch groove is which,, its fun to be our age isn't it??"

Switch groove??,, I gotta start proof-reading.. Should be 'which' of course..

[Duct Tape]

I have had my carb bank on and off about four times.  Ran good each time I put it back on but I kept getting fuel leaks.  I am finally getting the picture that I need to rebuild all of the carbs,  I'm kind of thick and kept hopeing that each time I did something it would fix it.  No such luck.  Where did you get the carb rebuild kits and how much were they?  Also did you have a shop manual or did you do it by the seat of your pants?
[/quote]

Got the kits from Rick at Red-Eye Tech in Kansas.  He sells on ebay also.  Willow had the website posted on another carb posting here.  I have a Clymer service manual -- good step by step instructions.  The first one took me about 3 hours.  The rest took me less than an hour each.  I was in no hurry.  Be patient.  A lot of very small parts.  I rushed the last one and dropped a couple small washers.  It was hell finding them.

It's running good.  I bench synced the carbs and was surprisingly very close when I put the gauges on.  Just some minor adjustments to finish the sync.  I set the pilots at 2 turns outs.  It's a little lean.  I'm going to back them out another 1/2.  Any further adjustment after that I'll probably do with either the tach or find a CO meter.

[Duct Tape]

The carb rebuild and rejet appears to have helped a lot.  Pre rejet highway mileage at 65-75 mph would only get me 26-30 mpg and a lot of flat spots and sputters on hard acceleration.  Post jet on the way to the Mid-winter ride I got 32-34 mpg and much better throttle response and greatly reduced flat spots.  Still seemed a little lean.  Backed out the pilots another 1/4 turn while in Austin.  On the way home got 34-36 mpg and throttle response continued to feel better.  I'm a little surprised at the last increase in mileage after enriching the mix.  I suspect the return trip may have been a little slower average speed with a different route.  A slightly richer mix should have sweetened the power a little, but dropped the mileage.   I'm going to keep it as is for a few hundred miles, and then plan to add the 4 degree trigger wheel.

[Ricky-D]

The carb rebuild and rejet appears to have helped a lot.  Pre rejet highway mileage at 65-75 mph would only get me 26-30 mpg and a lot of flat spots and sputters on hard acceleration.  Post jet on the way to the Mid-winter ride I got 32-34 mpg and much better throttle response and greatly reduced flat spots.  Still seemed a little lean.  Backed out the pilots another 1/4 turn while in Austin.  On the way home got 34-36 mpg and throttle response continued to feel better.  I'm a little surprised at the last increase in mileage after enriching the mix.  I suspect the return trip may have been a little slower average speed with a different route.  A slightly richer mix should have sweetened the power a little, but dropped the mileage.   I'm going to keep it as is for a few hundred miles, and then plan to add the 4 degree trigger wheel.

You have to figure that a richer gas mixture at the idle pilots may allow a lower throttle setting for the same power requirement, meaning you are staying on the low speed circuit more and less on the needle where the trade off is better gas mileage.   The good practice here would be to index your throttle and note the throttle setting while cruising. There's a wealth of information you can glean from this practice.

[Farther]

There's a wealth of information you can glean from this practice.

Like what?

[Ricky-D]

There's a wealth of information you can glean from this practice.

Like what?

Well, you're correct! 

That would mainly be affected by a persons intelligence and knowledge of the subject.

***

[Chrisj CMA]

There's a wealth of information you can glean from this practice.

Like what?

Well, you're correct! 

That would mainly be affected by a persons intelligence and knowledge of the subject.

***

Well I guess Im not smart enough either Farther.........I had the same thought....."like what?"

[Farther]

Well, you're correct!  That would mainly be affected by a persons intelligence and knowledge of the subject.***

  I was looking for a demonstration of yours.

[Ricky-D]

Ok, here is a link to a very good article about carburetors and tuning.

http://www.iwt.com.au/mikunicarb.htm

If you investigate this boys, you will understand a lot better.

***

[Farther]

So I read an article on the internet and now I is a rocket surgeon.