New XS400 Maxim Owner with questions

I just picked up a '83 XS400 Maxim 5 speed a couple of weeks ago with 11K on it. A nice sized bike to relearn on as I haven't ridden in about 25yrs. I think it will be a nice starter bike for my wife when I get a bigger bike hopefully next year.

I did down load the service manual that was posted here, (thank you to who ever up-loaded that) I could use an operators manual for it though.

Anyhow, I do have a couple of questions.

I'm not sure how to find out what letter (J,L,...) goes after the 400 but the engine VIN starts with 12R.

The last bike I had, the fuel petcock was "on, off, res" not "pri" so I'm not real sure how to use it properly. My guess is you use pri to start the bike when cold then switch to on after a few minutes. I did find that the small tube from the left carb boot to the inside nipple on the petcock was off. I've put 300 miles on the bike and just noticed it. The bike seemed to run fine, a little coldblooded so I don't know what the little tube is for.

The neutral, oil and brights lights work, but the speedo and tach lights don't. Can the bulbs be replaced and how do you go about it?

I've read all the posts here that have XS400 in the title and have learned a lot. I also believe I have a slight problem with the clutch slipping under power between 3rd to 5th gears. It seems fine in 5th. I changed oil today with some better oil as one of the carb floats stuck on me on my way home from work last night. Some carb cleaning will be in order this winter.

Thanks for reading and any input you can give me is appreciated.

Rich

 

'83 would be a "K" and '82 would be a "J."

The petcock is supposed to be vacuum operated. That missing tube is the vacuum line that signals the petcock to flow fuel.

In "PRI" it should flow fuel all the time. "ON" and "RES" are supposed to be vacuum operated. If you were getting fuel flow in "ON" with the vacuum line disconnected you have a petcock issue. With no vacuum it should not allow fuel past (except on "PRI.")

Petcock 101: http://xjbikes.com/Forums/viewtopic/t=25058.html

Be sure to check the rear brake for delamination right away: http://xjbikes.com/Forums/viewtopic/t=15874.html Serious biz, this is very common.

To replace the bulbs in your instrument cluster, you will need to open the headlight, unplug the connectors that go to the cluster and remove the cluster. Place it face down on a soft towel and remove the screws holding the back on, and lift off the back. You should be able to replace bulbs at that stage. You MAY need to remove the bracket from the back of the inner housing in order to unplug the bulbs.

Here's the teardown of a 550 Seca cluster; yours is similar but you have fewer things to unplug. http://xjbikes.com/Forums/viewtopic/t=14948.html

I would recommend 194-base LEDs instead of incandescent bulbs for the instrument lights. (Not for the indicators, they're too bright.) I used these: http://www.hipoparts.com/product_info.p ... cts_id=572 another source: http://www.superbrightleds.com/

Be sure to flush/bleed the front brake right away, and plan on new lines soon (they aren't supposed to last more than 5 years.)

One last important item: Keep an eye on the chain. Depending on the conditions endured by the bike before you got it, the chain could very possibly be internally rusted despite appearing ok, and therefore fail soon after being put back on the road. If it won't stay adjusted, and/or bleeds red when lubed, just replace it before it bites you. Be sure to replace chain and both sprockets as a set.

You're in the right place. Your XS is really "half an XJ" and has a lot in common with the 4-cylinder XJ series.

Welcome back.

 

bigfitz, thank you for all the info. It is greatly appreciated. Looks like I have some wrenching to do.

Two other things I forgot to mention,

The fork seals are leaking a little, so they will have to be replaced this winter. Any old posts about changing those anywhere? I haven't had the seat off yet so I don't know what the rear shock looks like.

When the carb float was leaking, I had to take the open the A/CL box to see what was going on. Well the air cleaner was just sitting on the bottom of the box, not functioning at all. It looks like there is a piece missing to hold the filter in place somehow or it's the wrong filter. I used a shim to hold it in place until I can get to the shop and get a new one.

Thank you again for your help.

Rich

ps, I don't quite recognize the town your from in Mich, I live in Oxford.

 

LOL. I had the same problem.

When you abbreviate Cows And Pigs And Chickens you get CAPAC. :wink:

 

MiCarl, thanks, thats too funny.

 

Barnyard humor. It's a popular local joke, I can't take credit for it.

With most of these bikes (admittedly I don't have a 400 but I do have 550s and a 650) there are ridges or ramps or flaps molded into the airbox lid to hold the filter in place aganst the opening. Yours is likely similar, you're not missing the airbox lid are you?

Chacal recently compiled all of the how-tos and informative threads into this forum in his section: http://xjbikes.com/Forums/viewtopic/t=27544.html

Front forks are pretty straightforward, just a pain. Yours are the same design-wise as the basic forks on the 550s and 650s.

 

bigfitz, thanks for Chacal's link. I will keep that link safe so I can find it again. what a wealth of info there.

I do have the airbox lid and side cover for that side. I'm missing the side cover for the battery.

I looked at the LED bulbs for the guages, do you think the red or blue would be bright enough or stick with white? Just thought some color would be neat.

Thanks again,

Rich

 

Here's a site dedicate to the XS400's SOHC and DOHC models.
http://xs400.com/

 

in the 400 airbox the filter goes over the opening and there is a metal curved piece that holds the filter in place. I may have a few lying around I can send ya as I NEVER run an airbox on my bikes. (No Flaming Please)

 

nother michigander... have fun with the bike,they're light and nimble,and i think they have a red line of 10 or 12K... pretty fun for a twin