xj engine miss

[DannyB]

on my xj11 it starts to miss at full trottle above 6500rpm i have not been able to figure this out would like any help here, also not getting vac. from #2 carb, i have plenty at the intake #2. by looking at plugs it appears to running lean.

it has a dyno jet stage three kit
4-1 header
accel coils
air pods

[dbeardslee]

Welcome to ch11! Have you checked for carb boot leaks? If you spray some wd-40 or starter fluid around the boots where they meet the head, if the idle rises you've got a leak. Keep a fire extinguisher handy - no joke. You might also check to insure that all the hose clamps are properly installed, and that all the carbs are properly inserted into the boots - should be able to tell with a flashlight.

[TopCatGr58]

Hey Danny,

Welcome to the site. Okay, XJ, but with POD filters! Stutters at 6k or so. Are the pods the cheap EMGO brand with a prominent lip on the mounting inside edge?? IF so, they are known to cause air flow problems with the carb intake ports and such. Quick experiment is to just take them off, and test ride. IF no stutter, then you've found the problem, modify the pods and their mounting...or get different pods.

The vacuum port of #2 carb doesn't create anywhere as much vacuum as the synch port on the boot. It is a small signal that goes to the BOOST sensor on the XJ to control advance timing for cruising rpms, but actually doesn't do much under hard throttle.

The accel's need good voltage to run, along with the TCI. Do you have the OEM glass fuses? Those clips can wear, get weak, glass fuses also corrode and can go bad. Have you checked the voltage at the coils (+) leads? Have you checked your battery and charging voltage?

T.C.

[petejw]

hey Danny,
welcome aboard,
Youll probably find the stage 3 kit to be to big, even with pod filters,
try dropping the main jet to the 128, and readjusting
your mixture screws.

[Ivan]

Had a similar problem once. Turned out to be a main jet worked loose and fell into the bowl. Also, if you have a dynojet kit with their jets, make sure the brass washer is under the jet. With those small jets, that's the only thing keeping a loose emulsion tube from sliding up into the carb throat.

Just a couple thoughts.

[DannyB]

miss

[QUOTE=TopCatGr58;275634]Hey Danny,

Welcome to the site. Okay, XJ, but with POD filters! Stutters at 6k or so. Are the pods the cheap EMGO brand with a prominent lip on the mounting inside edge?? IF so, they are known to cause air flow problems with the carb intake ports and such. Quick experiment is to just take them off, and test ride. IF no stutter, then you've found the problem, modify the pods and their mounting...or get different pods.

The vacuum port of #2 carb doesn't create anywhere as much vacuum as the synch port on the boot. It is a small signal that goes to the BOOST sensor on the XJ to control advance timing for cruising rpms, but actually doesn't do much under hard throttle.

The accel's need good voltage to run, along with the TCI. Do you have the OEM glass fuses? Those clips can wear, get weak, glass fuses also corrode and can go bad. Have you checked the voltage at the coils (+) leads? Have you checked your battery and charg

[DannyB]

miss

Hey Danny,

Welcome to the site. Okay, XJ, but with POD filters! Stutters at 6k or so. Are the pods the cheap EMGO brand with a prominent lip on the mounting inside edge?? IF so, they are known to cause air flow problems with the carb intake ports and such. Quick experiment is to just take them off, and test ride. IF no stutter, then you've found the problem, modify the pods and their mounting...or get different pods.

The vacuum port of #2 carb doesn't create anywhere as much vacuum as the synch port on the boot. It is a small signal that goes to the BOOST sensor on the XJ to control advance timing for cruising rpms, but actually doesn't do much under hard throttle.

The accel's need good voltage to run, along with the TCI. Do you have the OEM glass fuses? Those clips can wear, get weak, glass fuses also corrode and can go bad. Have you checked the voltage at the coils (+) leads? Have you checked your battery and charging voltage?

T.C.

i have emgos will mod and try again, i have removed the fuses and hard wired all the wires because of problems with the contacts breaking. i am am planning to put in a blade type fuse box. if i can get pass this miss problem.

[dbeardslee]

i have removed the fuses and hard wired all the wires because of problems with the contacts breaking.

Dude! Bad idea! Those fuses are there for a reason and you're taking a real chance operating it without them - particularly on a bike that's having issues. One short and you can wind up with fried wires and components. You might even get a fire started. My advice is get the fuses back on there quick.

[DannyB]

thanks t.c.

Hey Danny,

Welcome to the site. Okay, XJ, but with POD filters! Stutters at 6k or so. Are the pods the cheap EMGO brand with a prominent lip on the mounting inside edge?? IF so, they are known to cause air flow problems with the carb intake ports and such. Quick experiment is to just take them off, and test ride. IF no stutter, then you've found the problem, modify the pods and their mounting...or get different pods.

The vacuum port of #2 carb doesn't create anywhere as much vacuum as the synch port on the boot. It is a small signal that goes to the BOOST sensor on the XJ to control advance timing for cruising rpms, but actually doesn't do much under hard throttle.

The accel's need good voltage to run, along with the TCI. Do you have the OEM glass fuses? Those clips can wear, get weak, glass fuses also corrode and can go bad. Have you checked the voltage at the coils (+) leads? Have you checked your battery and charging voltage?

T.C.

you were right it was the filter pods. been over a year sorting this out thanks for your help.