Trouble with first start after several years

After pulling out my dad’s bike (which has been passed along to me) out of storage a few months ago I cleaned the Carbs checked the valve clearances and everything seemed fine. When I try to fire it, it suddenly jumps to around 5k rpm and stays there. I can tell that it is running very rich. The throttle is free to move and does not hang up. I have not been able to find any air leaks around the carbs or the carb boots. Anyone have any ideas what this could be?

 

As much as it sucks, you're probably going to have to clean the carbs again, sounds like the pilot jets might still be clogged...

Before you do that though, have you tried adjusting the idle control knob that's tucked away between the second and third carb bodies? Running rich can probably be solved by doing a sync and colortune.

Hope I could help.

 

Make sure you didn't get the throttle and choke cables backwards when you hooked them back up.

 

If it starts your in good shape. I would suggest the same as those above. If it climbs to 5K quickly maybe all the carbs are malfunctioning the same pointing to a cable or an external mechanical linkage problem ? Before re-installing the carbs move the throttle assy by hand making sure all the linkages are moving at the same time and that at rest all the carbs are in the fully closed position. I found refering to a service manual and the instructions with the carb sync tool really necessary. These sync gauges or meters are a little expensive but well worth the money now and in the future ( I sync my carbs every year ) Smooth performance and ease of starting will be really improved. Don't forget to use a YICS shut off tool when setting up the carbs if your bike has this feature.

More information on everything I mentioned above is available from those of us on this site, afterall that's how I was able to get my own bike up and running lol

good luck

 

Yesterday I inserted the YICS blanking tool and it ran a lot better. I have one cylinder that is running good and the other three are excessively lean even if I back the low speed needle out almost all the way. Sound like another cleaning?

 

I have finally found the fix to the problem that I was having. I was trying to run the bike without the air filter in. I called the Yamaha dealership and talked to them for close to an hour and they told me just to put the air filter in and give it a shot. After syncing the carbs, its running like new.

 

fishinchickens,

Welcome to the Club. Post your model in your signature so the members will know which bike you have.

Gary

 

It is clearly written in the manual that you sholdn't run the engine without air cleaner unit connected. Now you know (and I know too!) what kind of problems could result.