Carb advice needed.....

[Andy]

Hey,
Can anybody tell me what size main jet they are using in their 73a please,the reason i ask is because i spent some time on mine today(carb strip etc) and it`s running 95 mains but seems to be suffering top end (12k plus) and i was going to try 90 mains.....
Anybody have any experience of this problem?

Andy

[Variablevalves suck]

Hi Andy,
I only got a parts list for a RK model and it lists 97.5.

[Jaicen]

I can't speak for the GK73, but the 71 uses a 94 main jet, so 95 sounds about right. I think i'd look elsewhere for the problem.
Check the filter on your fuel tap etc..

[Andy]

Hi Andy,
I only got a parts list for a RK model and it lists 97.5.

Cheers fellas,
I`ve set the float heights,changed the `o` rings set the mixture to standard and still feels a little `wooly up top` it`s nothing serious but annoying all the same considering it revved out all the way before the strip,the low rpm/midrange was shocking though and now it`s lovely and fluid and will stand full throttle in top at 3k showing on the rev counter and pull smoothly right out to about 12,500......fix one problem and inherit another,good job it interests me!

Andy

[Variablevalves suck]

If it was running ruff before the o'rings its because the bikes run rich so if the top was better before, you may need to up the mains a little to give the same effect, say 2 or 3 on the size. Do you have a race can as these can ask for slightly bigger jets due to the motor runing free'r.

[Andy]

If it was running ruff before the o'rings its because the bikes run rich so if the top was better before, you may need to up the mains a little to give the same effect, say 2 or 3 on the size. Do you have a race can as these can ask for slightly bigger jets due to the motor runing free'r.

Running viper cans on twin system at the minute but that was the set-up on it when it revved out before the strip!!! All will have to wait until the weekend now Chris due to another set of downpipes(originals holed/rusty) coming this week.I would really like to keep the twin cans if possible(i know a local pipe-bender/welder) but i`m led to believe a single outlet gives more power,is that true?
Cheer`s
Andy

[Variablevalves suck]

Andy, dont think the twin pipes will make any difference to power as they meet up under the motor before spliting so efectively give a 4/2/1/2 set up and the factory gives the same BHP for all models. People run the single out let as you are going to be saving a few pounds by losing a silencer.

[Andy]

Andy, dont think the twin pipes will make any difference to power as they meet up under the motor before spliting so efectively give a 4/2/1/2 set up and the factory gives the same BHP for all models. People run the single out let as you are going to be saving a few pounds by losing a silencer.

Cheer`s,twin pipes it is then.....

Andy

[Andy]

Ok,
After further tinkering with mains,mixture/pilot sizes/settings i`ve come to the conclusion my bike hates me.....seriously my finding`s are as follows;

1,Increasing the mains give`s a strong top-end and clean rev-out to and if you let it past the red line BUT the trade of is a loss of mid and wooly idle/slow speed control...

2,Decreasing the mains improves the low/mid throttle response marginally but crucifie`s the top-end completely

All above was with standard settings;mixture/float height etc....

My initial thought`s were go with setting 1 and change pilots etc to sort the low end response out but quite by chance i noticed the `new` jets i was using were approx 2 mill thinner than the originals hence lowering the float height by the same in theory....mmmmm
A float check and set(i hate float setting!)later and bingo it feels just as it did before but with a top-end for a change,nice
There is still some wooly bits(marginal) but i think some experimenting with the pilots will cure this but i`m going to leave that untill the new d/pipes are fitted etc...

When it is finalised and i`m happy with it i`ll post my setting`s etc(when i`m sure it`s good!)

Happy,happy,happy

Andy

[Variablevalves suck]

Good to hear!
Could be just wear in the carbs but lowering the throttle tickover and lifting it back up with a little more on the pilot screws could help. theres a link to a book ive got that just happens to show the carb section, could be of help to ya.
http://books.google.co.uk/books?id=4FHL ... q=&f=false" onclick="window.open(this.href);return false;

Chris.