Bike wont run and I blame my carbs.. Need some help with a few simple question

[madmaze]

Hello Everyone,

I have an 83 gs450, which i got for free with parts taken off..
so i have put all of it back together and i think everything should work.

I have cleaned the carbs and since im using K&N-like pod filters I went up on my main jets from 115 to 125.

and since i know someone is going to ask:
-I put pod filters on because when i got the bike the air box was cracked and had mice nested in it..
-and Ive tested the spark.. even new plugs

So here is the main thing i have tried 115's 125's and 127.5's main jets.
but otherwise i havent done anything (except clean the carbs).. It just doesnt run. sometimes after it sits a while and i try cranking it again it will fire once or twice but thats it.

any suggestions?

this is my setup:

 

[Guest]

Check compression and the timing with a light

 

[TheCafeKid]

Hello Everyone,

I have an 83 gs450, which i got for free with parts taken off..
so i have put all of it back together and i think everything should work.

I have cleaned the carbs and since im using K&N-like pod filters I went up on my main jets from 115 to 125.

and since i know someone is going to ask:
-I put pod filters on because when i got the bike the air box was cracked and had mice nested in it..
-and Ive tested the spark.. even new plugs

So here is the main thing i have tried 115's 125's and 127.5's main jets.
but otherwise i havent done anything (except clean the carbs).. It just doesnt run. sometimes after it sits a while and i try cranking it again it will fire once or twice but thats it.

any suggestions?

this is my setup:

Stock pipes or no? If not, You're still by my guess a couple sizes too lean on the main...bump it up to about 130, or a 132.5. Somewhere around there... Without a header, try another size or two bigger on the main. Also, in all honesty, were I you, i would simply find an airbox rather than deal with the PITA that is pods on these bikes. Yes, it can be tuned to run well...ive FINALLY done it, with much anger and frustrations, and a Dynojet kit (do they make one for the 450?) but the trade offs of even a decently tuned pod bike and a decently tuned 'box bike are to many cons vs pros IMO. At any rate, you'll need to do a bit more tinkering with the carbs if you choose to keep the pods. After the main is figured out, you'll need to do something about shimming the needles, and then dial in your pilot screw settings...Really man they are a pain in the butt.

 

[madmaze]

no i havnt..
But at some point i had it running for a few seconds at a time by lifting the diaphrams with screwdrivers..(I know thats bad, but i just wanted to have it make a sounds =P)
I really think it may have to do with the carbs..

 

[madmaze]

Stock pipes or no? If not, You're still by my guess a couple sizes too lean on the main...bump it up to about 130, or a 132.5. Somewhere around there... Without a header, try another size or two bigger on the main. Also, in all honesty, were I you, i would simply find an airbox rather than deal with the PITA that is pods on these bikes. Yes, it can be tuned to run well...ive FINALLY done it, with much anger and frustrations, and a Dynojet kit (do they make one for the 450?) but the trade offs of even a decently tuned pod bike and a decently tuned 'box bike are to many cons vs pros IMO. At any rate, you'll need to do a bit more tinkering with the carbs if you choose to keep the pods. After the main is figured out, you'll need to do something about shimming the needles, and then dial in your pilot screw settings...Really man they are a pain in the butt.

hmm yea ive considered going back to an air box.. I think ill go look for one.. but i've already put alot of time and effort into this so it would be a bummer to just give up and let the machines win =)

ohh and no i have stock pipes.. still think i should try bigger?

 

[nvr2old]

Have you tried taking the float bowls off and manipulting the floats by hand to make sure they're turning the gas flow on and off correctly. Simple test to make sure they're not stuck. If they're slightly sticking in the up position they'd be shutting off the fuel, until it sits for awhile and slowly refills the bowls, maybe then allowing it to run for a little while before running out of fuel before it fills enough again to keep it running. Just something easy to try and to check off the list.

 

[madmaze]

Have you tried taking the float bowls off and manipulting the floats by hand to make sure they're turning the gas flow on and off correctly. Simple test to make sure they're not stuck. If they're slightly sticking in the up position they'd be shutting off the fuel, until it sits for awhile and slowly refills the bowls, maybe then allowing it to run for a little while before running out of fuel before it fills enough again to keep it running. Just something easy to try and to check off the list.

actually they are in great condition.. and move freely

could it be i need different pilot air/fuel jets??

 

[Big T]

The size of the jets shouldn't affect if it will run - just how it runs

Are your plugs getting wet?

Is there fuel in the carb bowls?

 

[madmaze]

The size of the jets shouldn't affect if it will run - just how it runs

Are your plugs getting wet?

Is there fuel in the carb bowls?

hmm so i should still run.. hmm.. By "plugs getting wet" you mean if fuel gets into the comb. chamber.. I can smell it if i crank without the plugs in.. so i assume so..
and there is def gas in the carb bowl.. maybe ill check the float level..

 

[salty_monk]

Gas, spark, compression... those are the 3 things needed to get a running bike... can only be one of them.

Once you know you have all 3 of those look at timing.

Confused about "lifting the diaphragms with screwdrivers". If that works you're making it much richer (but how are you getting to them, you'd need no filters & throttles wide open??)

I think maybe your choke circuit is not working correctly. Maybe the tubes that dip down into the bowls to pull in more fuel are blocked?

Dan

 

[Big T]

That's essentially correct

If you're cranking it to start, the plug tip and base should get wet with gas

Also, I note that you mention testing the spark - what color did it show - yellow, blue. red, white?

What voltage is being delivered to the coils? 12V?

The reason I ask is, you need air, fuel and spark to combust. Air is plentiful, so no sense checking that.

If your plugs are wet with gas, then fuel is being supplied

And, that leaves spark - a weak spark on the plug out of the cylinder may be little or no spark in the cylinder. A common cause of weak spark is corroded wiring fasteners. So check to see what voltage is at the coils.

many people do the Coil Relay mod to work around low voltage at the coils.

 

[Guest]

If it runs with the slide lifted your pilot jet is plugged.

 

[Stefnwolf]

From your picture it doesn't look like the carb boot O rings have been replaced. If not, it is likely they will need to be done.

Can you get it to run by spraying easystart or carb cleaner into the intakes?

 

[madmaze]

OK, so now it run.. sorta..
Thanks for all the tips, i am not quite sure what in the end did the trick.. but i cleaned the choke fuel supply line.. and i took the plugs out of the pilot jets and i went through and cleaned everything else again for the 10th time..

Now I was able to run it last night on one cylinder and today for some odd reason it fired up on both.. I can even turn off the choke now and it continues running. but now if i get to around 4k-4.5k rpms the exhaust turns into more smoke than anything..

so am i right with the idea that im running too rich at that point??

 

[twiggy2cents]

black or blue smoke?

 

[madmaze]

black or blue smoke?

well its not blue.. not really black its more like white..
which doesnt make much sense to me.. since that is usually, atleast with cars, combusting antifreeze lol..

well i ran it again just now.. and Its behaving wiered.. it stayes around 2k rpm and then every now and then reves up to about 3.5k i didnt have that happen yesterday..

I can run it fine on the left cylinder but the right one wont stay going without the starter..
maybe something is plugged up again on the right one.. i dont know

 

[reddirtrider]

From your picture it doesn't look like the carb boot O rings have been replaced. If not, it is likely they will need to be done.

Can you get it to run by spraying easystart or carb cleaner into the intakes?

I have a feeling this is your problem.

 

[salty_monk]

Yep, you have air getting in somewhere...... Likely the O rings.

The white smoke - I wouldn't worry too much about for now. They all seem to do that for a few miles after a rebuild (at least mine did). Maybe burning off remnants of carb cleaner, dust out of the headers etc.

Dan

 

[twiggy2cents]

mine makes a little white smoke on cool days as the moisture starts to evaporate but yes it sounds like intake orings bad

 

[madmaze]

what are the intake - o-rings?
the rubber things connecting the carbs to the block??