Carbs GS1978

[Marc64]

I own a 1978 GS750 not sure what model reg 01/08/78,the carbs are worn,and having trouble finding original replacement.Does anyone know wether any other carbs would fit as an alternative.Thanks in advance.

[hampshirehog]

Carbs from a 77-79 GS750 or 79 GS850 will all work if you want to keep it simple. How are they worn out btw? Usually they're fixable.

Oh - and welcome to the funny farm aka the GSR.

[Nessism]

I suggest you rebuild the carbs you have. Rebuild tutorial here... http://www.thegsresources.com/files/vm_carb_rebuild.pdf and O-ring kit from cycleorings.com

Purchasing used carbs is a bad idea since they will have to be rebuild anyway because the rubber O-rings are 32 years and very prone to leakage.

[SqDancerLynn1]

Unless the carbs have 100K miles or someone has ham fisted them they are rebuildable. Usually just need a very good cleaning & new O rings maybe float bowl gaskets. I have seen people have the slides recoated- I don't know who would be able to do it..

[Marc64]

Thanks for your advice.I think i've mainly got a problem with the outer left one.I run a heavily modified rat gs,but as far as i know the engine is standard.The exhaust is a cut down race can,the carbs are enclosed by a home made air box but the outer carbs are fitted with k+n's,a ledar air corrector kit has been fitted.When we were setting the air and fuel mixtures we were using a glass spark plug so we could see the spark,3 of them when went blue on the spark from orange but the fourth one no matter how much we turned the mixture screws we could'nt get the spark to go blue .When u rev the bike up and release the throttle the revs drop but not down to idle speed and sometimes it does'nt drop down,so i was thinking of getting a carb rebuild kit for the one,but would i need new screws etc.

[SqDancerLynn1]

Check the intake boots first & replace the intake O rings, The carb kits are usually not needed

[hampshirehog]

If that carb is showing white on the colortune it's running weak. As SqDL says check the boots and O rings but if it's no.3 check the tube to the vacuum tap is fitted (or block it off if it's not fitted with the vacuum tap).

If the carb is running rich (yellow flame) check the float height and that the float valve isn't worn.

No 1 cylinder (and carb) is the left one as you sit on the bike looking forward, no.4 is on the right btw.

[Guest]

You're saying the inner two carbs have a homemade airbox and outside two have K&N pods with these carbs using press in main air jet correctors.