Help to richen gs450 fuel mixture. Not as easy as your thinking!!

[Darren GS450T]

Hi, yet again another 1982 gs450 running to lean, I have had advice on here before (thank you all good), but I am not getting the answer to my problem. Cannot get fuel mixture rich enough, have to ristrict the air into air box to get the bike to rev properly. I have done all obvious, carb refurbish, jets are standard, no needle adjustment, new air filter, no leaking joints & removed idle mixture blanks and adjusted them, etc etc etc. I can only think I need bigger main jets or thinner needle? I am cutomising bike and running K&N type filters in the future, but that shouldnt be a problem. Bigger jet sizes please and part numbers, no emissions test here for me to worrie about, just need more fuel. Thanks, Darren, Lincolnshire, UK.

[tkent02]

Have you tried using bigger main jets and shimming the needles?
Plug chops to determine which circuits are too lean?

[Darren GS450T]

Thanks for shiming needle idea, I have never thought of that.

[Steve]

Thanks for shiming needle idea, I have never thought of that.

Yes, it's a great idea.

Now, ... do you know how to do that?

.

[Darren GS450T]

Well, I would think it means putting spacers under the c-clip of the needle to lift it, but I havent got a carb in front of me at moment, please give me any advice, so when I get home this evening I can have a look. Thanks again, Darren.

[Nessism]

Well, I would think it means putting spacers under the c-clip of the needle to lift it, but I havent got a carb in front of me at moment, please give me any advice, so when I get home this evening I can have a look. Thanks again, Darren.

Actually, you need to remove the plastic spacer on TOP of the clip and replace it with a washer stack that is shorter. There is a spring that pushes up on the needle and the height is controlled by the spacer on top of the clip.

[Darren GS450T]

Thank you for that info, I shall be tinkering tonight. I have been looking through other threads on this subject and it appears I will have to go up about 8 main jet sizes (what size will that be?). I am building a hard tail bobber that will have exhausts with a turn out pipe and no mufflers, also K&N type pod filters on carbs. The size 165 mains has been mentioned, what about pilots? Darren...

[Nessism]

You better go back and read some more, 165 is NOT what you need. Regarding your bobber project, I'm glad you in the UK and not in my neighborhood.

[Darren GS450T]

Thats good, Im lucky that people in my neighbourhood are tolerant of other people, and the way they live their lives, not like some neighbourhoods were people are boring and like it quite all the time, anyway if 165 is not correct would you share you knowledge with me of what would be the correct size, or a least close to the jets I need. Thank you once again. Darren.

[Steve]

Stock main jets are 115, according to the list that I have. Eight sizes up would be 135.

You say you will be using "K&N-type pod filters". That will change your jetting requirements, too. I can't say for sure exactly what you will need, but if they are true K&Ns, they will likely require different jetting than "K&N-type" filters.

Keep in mind that this is a starting point, your actual needs will need to be determined by plug chops to see the color of the plugs. They will tell you very quickly how close your jetting is.

Regarding the neighborhood: just because your neighbors are tolerant doesn't really mean they enjoy or even appreciate the noise.
Most of us are rather tolerant of others and their life styles, but we also appreciate the relative quiet, too.

.

[SqDancerLynn1]

the 165 # may have refereed to the jet # in a kit, no relationship to factory #s In the US we can get a package of washers from radio Shack. In the UK?? I believe you need 3mm flat washers

[Darren GS450T]

Great help chaps, is it possible to drill out the jets, what relationship does the jet number have with the hole in the jet, what size drill would turn a 115 jet into a 135 jet??? Darren

[Darren GS450T]

Can you drill jets to increase flow? Thanks. Darren.

[Darren GS450T]

Hi, if an increase to 135 main jets is carried out, what pilot size would be correct. Darren