GS450 Carb rebuild

[jola]

OK so my motorcycle usually takes a long time to warm up and when the choke is on full or even just half choke the throttle response exhibits poor responsiveness and sluggishness. I was pretty much assuming this is due to dirty carbs since I do not think they have been cleaned lately. Would this be accurate. Otherwise the motorcycle runs fine as far as I can tell. Should I still rebuild them with the O-ring kit? I would also order the gaskets if I can find them from somewhere.

Secondly, if I do rebuild them, can I use the posted tutorial even though it refers to motorcycles after 1980 and mine is an 80 GS450E?

[jola]

OK, I found a set of bowl gaskets at Z1 so I'd be set there. What is this synchronization business? I don't want to have to buy an expensive tool.

[Dogma]

If your carbs are the same type (CV with the diaphragm on top) you should be able to use that tutorial. I've read elsewhere that the other carbs used by Suzuki on the GS series is simpler, but similar principles apply.

However, even though your carbs may need rebuilt, make sure your valve clearances are correct. This is a lot easier and a lot less work than rebuilding carbs. Even more importantly, correct valve clearances are a prerequisite for tuning carbs.

Synchronizing or balancing carbs is the process of making sure that all the carbs open from idle in a balanced fashion. This is necessary for smooth idle and reduced vibratio nat speed. It's been described a few times on the forum so a search should get you the information you need. I haven't done it myself yet, so I can't give you the details. The expensive tools aren't necessary if you're willing to build your own. Search the forum for a thread called "ghetto manometer".

[jola]

If your carbs are the same type (CV with the diaphragm on top) you should be able to use that tutorial. I've read elsewhere that the other carbs used by Suzuki on the GS series is simpler, but similar principles apply.

However, even though your carbs may need rebuilt, make sure your valve clearances are correct. This is a lot easier and a lot less work than rebuilding carbs. Even more importantly, correct valve clearances are a prerequisite for tuning carbs.

Synchronizing or balancing carbs is the process of making sure that all the carbs open from idle in a balanced fashion. This is necessary for smooth idle and reduced vibratio nat speed. It's been described a few times on the forum so a search should get you the information you need. I haven't done it myself yet, so I can't give you the details. The expensive tools aren't necessary if you're willing to build your own. Search the forum for a thread called "ghetto manometer".

Thanks Dogma. For some reason I am afraid of checking my valves, but if it much be done it must be done. I don't have a job, so I have plenty of time to screw stuff up.

[tkent02]

OK so my motorcycle usually takes a long time to warm up and when the choke is on full or even just half choke the throttle response exhibits poor responsiveness and sluggishness.

That's pretty much how these bikes work when cold, might not be anything wrong with it.
New O rings can't hurt, adjusting the valves is a great idea. The carbs usually don't need cleaning until they sit for months with fuel in them.

[jola]

That's pretty much how these bikes work when cold, might not be anything wrong with it.
New O rings can't hurt, adjusting the valves is a great idea. The carbs usually don't need cleaning until they sit for months with fuel in them.

OK, well that's reassuring. I partly want to do it just to gain experience since I've never worked on carbs before. Also, I have no idea when the last valve adjust was done, so I suspect I could benefit from adjusting them.

I think I may wait till riding season is over since she runs decent right now.

[Dogma]

Thanks Dogma. For some reason I am afraid of checking my valves, but if it much be done it must be done. I don't have a job, so I have plenty of time to screw stuff up.

I was discussing that with someone recently. People who've never done it are intimidated by it. It's really not that bad. Getting the old gasket off is the only hard part.

[jola]

That is reassuring. I looked up some parts and feeler gauges (the kind where there are 10 or 20 bolted on one and like a swiss army knife) are less than $10 but shims are over $100 if I buy the big set. I guess the cheap but slow way to go is to measure first then order the shims I need. After looking through Cliff's tutorial I think I'll be up for the challenge on an ambitious day. After that there is no turning back!

[Dogma]

That is reassuring. I looked up some parts and feeler gauges (the kind where there are 10 or 20 bolted on one and like a swiss army knife) are less than $10 but shims are over $100 if I buy the big set. I guess the cheap but slow way to go is to measure first then order the shims I need. After looking through Cliff's tutorial I think I'll be up for the challenge on an ambitious day. After that there is no turning back!

You got it exactly right!