Running Bad

[chiefpage]

My 05 Rex just started running bad. It will start and seem to run good at low RPMs but when I'm riding it runs like it is running out of gas. I'm thinking it is either bad gas or a carb problem. I lifted the tank off last night but did not completely remove it, could I have pinched something? Any suggestions?

[Bama109]

I am having the same problem. I removed the tank and drained the fuel- no water or trash. All four plugs were good. The bike starts breaking up or missing around 3000 rpm. It cranks and idles fine though.

[TGHW]

If the bike has been sitting for any length of time it is probably dirty carbs. Two other things that you can check are the small black vacuum line that runs from the no. 2 carb to the petcock. Make sure it is not kinked or it will not open the petcock properly. Also, if your bike still has the airbox, make sure that the lid is installed correctly. There are tabs at the bottom of the lid that need to be engaged or the lid will allow too much air to get in.

One way to check to see if the pilot jets in the carbs are partially plugged is to leave the choke on and see if it runs better above idle. If it does, the carbs need cleaning. You can also try running some Seafoam fuel treatment through it. If they are not too dirty that will sometimes clean them up.


TG

[Bama109]

Thanks - I will try the choke trick. My bike only has 3100 miles on it but it has been running good. It actually started running bad during a short afternoon ride. I don't get to ride very often but I do try to run the bike at least every two weeks. Also, I currently have Seafoam in the tank.

[TGHW]

Just to clarify, the choke on a ZRX is not a choke in the traditional sense. It is an enricher that adds fuel. That's why you can use it to see if the pilots are running lean.



TG

[zrxrob]

could also be a gas cap venting problem

[Jethro]

Generally when it feels like it is running out of fuel it is a dirty carb problem
If one of your vac caps is not ruptured, your carbs need to be cleaned

Have fun...............

[Wolfman]

Put it in the "Prime" postition on the petcock next time, and see if it changes anything. That will tell you if it's a vacum line issue.

[Bama109]

OK I tried the choke trick and it made a slight change. But overall it is still rough over 3K. If I rev it up with half choke it will sometimes shoot a blue flame out of the exhaust. Before I rip out the carbs is there any chance of this being an electrical problem? Thanks for the help. As you can tell I am not a mechanic...........................

[zrxrob]

OK I tried the choke trick and it made a slight change. But overall it is still rough over 3K. If I rev it up with half choke it will sometimes shoot a blue flame out of the exhaust. Before I rip out the carbs is there any chance of this being an electrical problem? Thanks for the help. As you can tell I am not a mechanic...........................

you've got trashy carbs (dirty little bitches!) whereabouts in Bama is ye?

[TGHW]

Just in case, check your battery voltage, both static (ignition off), and then while you're cranking the starter. Is it original? Do you use a battery tender?


TG

[KWICK]

http://kwickstand.net/Hyper-Formance..._Cleaning.html

[bossracer]

Put it in the "Prime" postition on the petcock next time, and see if it changes anything. That will tell you if it's a vacum line issue.

do this. I've pinched and or failed to re-install the vacuum line to the petcock numerous times. You MUST do this before proceeding with troubleshooting.

although from your description, it sounds like carbs. You simply can not let the bike sit with todays crappy fuel in it. I've had fresh carbs gum up in a week. If you know it is going to sit, remove the fuel supply line to the carbs and let it run until it dies. this will help.

Try Berryman's. Entire "small" can in the tank. Go ride.

[Bama109]

Thanks for the help - I'll check these tips before I tear it down this weekend.

zrxrob - I'm in south AL about 80 miles north of Mobile.

[Wolfman]

Just a small road trip away.
I also woulf check the battery. Have it load tested and static voltage tested (auto zone is free), but it sounds like dirty carbs.
Rule out the simple, cheap stuff first. Are you SURE it's getting gas from the tank. (clear filter install in line helps.)
Try reserve,prime, etc. all BEFORE pulling carbs.