1982 xj 1100 boost sensor

[mwsxj1100j]

Thanks to all who have helped me out with their tips. I think the first gear slipping out at 3000rpm will have to be set aside for now since it seems to run just as well from 2nd than if in 1st I can use 1st as long as I do not exceed 3000 rpm. I really don't have the ability to get into the gear box also I cannot locate the fix guide. My issue today is the boost sensor. The mechanic who worked to get bike running straight linked the vacuum line from the intake horn that is attached to the heads to the nipple on carb number 2 to get it TV to run. Although there is a noticeable lack of power since the boost sensor is not connected. Does the vacuum line go to the boost sensor to the intake horn attached to the cylinder head or to the nipple on the carb? Which should be blanked off? Or should I connect both to the boost sensor? Thanks

mws82xj1100j@att.net

[crazy steve]

That 'boost sensor' is actually a vacuum switch that tells the TCI box to advance the timing under low load/small throttle opening operation. The vacuum supply should be connected to the #2 carb nipple, not the intake boot. Note that the sensor not working really shouldn't effect power, just fuel economy, so if you're down on power there's something else wrong. Make sure you have the right ignition box; yours should have a '10M' part number on it. If you have either of the other two used, the timing will be off and power will be down. The 10M box was an XJ-only part, so they can be hard to find....

[TopCatGr58]

Hey Steve,

Several years ago a fellow with an XJ burned up his 10M Tci, could not find one, but had a 4RO unit, tried it and it worked just great. Because the 81 4RO has the Cent. Adv. curves built into it, and like you said, it's the power curve, the VAC. adv. is only for fuel economy at low load/throttle settings.

SO...yes, if he still has OEM 82 XJ timing parts under the left crank case cover, but he has the 78-80 2H7 series TCI, then yes, he will not have any power....BUT if he has the 4RO TCI it will perform essentially as good as the 10M unit...without the VAC. adv./Boost Sensor connected.

So...yeah, MW, if you DO have the 10M OR the 4RO TCI, and poor power response, then there's something else wrong with the bike....carbs, hitting on all 4, etc.! But if you have the 2H7 TCI then you WILL have power problems because you're not getting any decent timing advance=power!

T.C.

[trbig]

What do you mean about the gear "Slipping out"?

[mwsxj1100j]

1982 xj1100j boost sensor

I have noticed that without the boost sensor the fuel econ is not as good. As for the transmission when in first gear as soon as the tach reaches 3000 rpmthe transmission goes into neutral. I either shift into second before hitting 3000rpm or take off in second gear. Going back to the boost sensor I just remember the bike having more get up and go maybe it is because I haven't rode the bike since my accident April 2010. It seems to be running decent as well as a 33 year old motorcycle with 11,000 miles after an accident can run. I just hate the transmission it shifts like an old Russian farm tractor. I still am having trouble getting the led tailight bulbs to stop sending a malfunction signal to the lcd dash. I think I need a load resistor since the bulbs put a much lower load on the electrical system. Also that stupid battery sensor is a pain I saw a guide on how to fool the computer it said to go to Radio Shack to get the parts but with radio shack going thru chapter 13 the stores are getting hard to find. Oh well, I did installed a wolo bad boy dual tone air horn I mounted it where the brake line support is for the linked brakes go to the front caliper using the same mounting location of the original horn using the included relay.

Thanks for all the help.

[DiverRay]

Also that stupid battery sensor is a pain I saw a guide on how to fool the computer it said to go to Radio Shack to get the parts but with radio shack going thru chapter 13 the stores are getting hard to find.

OK, I started in the middle....
Here is the link to Jerry's mod: http://http://www.xs11.com/forum/showthread.php?t=668
The one thing you will need is a 2K Ohm, 1/2W resistor. You should be able to get one someplace close. The wire and bullet connectors you can find at any auto parts store, or even at ACE Hardware!
The sifting sounds like an adjustment. If you look at the shift spring pictures, you will see in the first one that there is a dot in the shifter forks that line up with a dot on the shift drum side when in second gear. The second gear repair tutorial has a good view, and how to adjust. This should take care of the first problem for a little while. http://www.xs11.com/forum/showthread.php?t=2785The XJ had FIRST gear go before second for some reason. The fix is about the same, just different dogs/gears.

[trbig]

This doesn't sound like a 1st/2nd gear issue these bikes have. Sounds more to me like you just have a bent pin in your shifter drum, or you have a bent shift fork. The pin is an easy fix behind your shifter lever cover. The shift fork entails more and getting into the transmission.