Introduction and Advice Needed, for 83 maxim XS400

Happy NYE everyone!

I'm back with a couple questions about my next step in my first motorcycle project. The topic of this post is Carburetors!

First question. I plan to run a cut off exhaust with "hi flow" mufflers. I've seen folks on this forum and others say that running a free flowing exhaust will necessitate a re-jetting of the carbs. I would imagine that means running a larger jet size?

Second question. I purchased 2 carb rebuild kits from mikexs.net a while back. I'm wondering if I need larger jets, are they included in the kit? It seams to have a bunch of jet options available. Pic of what the kit contains attached below.

Third Question. If anyone has any advice, links to "how toos" or sweet step by step instructions/videos on carb rebuilding, SEND THEM MY WAY!! I have the service manual on hand, but any other tips n' tricks would greatly be appreciated!

Thanks!
 

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If your stock mufflers are still good DON'T CUT THEM!! Find a crappy set to mess with. You may want or need to put the stock ones back on to get the bike running its best. Any non-stock setup will need tuning and adjustments. Your stock setup will give you the best overall performance.
 
Back from the thread graveyard of page 3....

It's finally starting to feel like spring here in Chicago! And that means I can finally try and get this bike started!

Thanks to everyone with the advice on how to winterize my ride a couple months ago, but now I need tips on "un-winterizing" this beast. Below is a punch list of items I could use some advice with...

- I fogged my motor before the winter. Are there any extra steps to "un-fog" the motor?
- I got new oil filters from MikesXS.com but they didn't come with filter casing O-rings. I should be able to bring the old o-ring and casing into a parts store and find a new one, right?
-The handbook says I should use 20w-40 motor oil on for my bike, but I can't find that weight oil anywhere! Is 20w-50 ok? Also my sight glass is pretty FUBAR'd and being a super cold start...does anyone have a round about idea of how much oil should go in the crank case before a first start?
-I need new fuel lines. Any idea on the size line I need? I need to make sure I get the right size line and fuel filter combo
-can someone please send me a pic of the start/kill switch controls on a 83 Maxim 400XS, time has not been nice to mine and I can't read them. I don't wanna be that guy thinking his bike is broke when the off switch is on...

Besides that do any of y'all have advice on starting a bike that hasn't started since at least last summer?

Thanks!
 
Yes, 20-50 will work. Advise using semi synthetic as a starting point. Fill to 3/4 of oil level window. Methelhydrate in the tank...1 oz, fresh premium gass, full charge on the battery via tender. 1/4" inner diameter fuel lines with a fuel filter in line. Switchs, up to start toward front tire, down to kill. The O rings are specific to the filter. usually the filters come with the rings to replace. You should be able to find the O rings at a quality parts shop. Another great site for parts is CMSNL.com over in Europe. A great source for NOS parts. Once you get all that done, fire it up. See what you get.
 
Yes, 20-50 will work. Advise using semi synthetic as a starting point. Fill to 3/4 of oil level window. Methelhydrate in the tank...1 oz, fresh premium gass, full charge on the battery via tender. 1/4" inner diameter fuel lines with a fuel filter in line. Switchs, up to start toward front tire, down to kill. The O rings are specific to the filter. usually the filters come with the rings to replace. You should be able to find the O rings at a quality parts shop. Another great site for parts is CMSNL.com over in Europe. A great source for NOS parts. Once you get all that done, fire it up. See what you get.

Thanks so much Warren!!! Once I get this beast started I can get a start on the building it up, I'm sure it'll be an adventure lol
 
One thing I do when I take the bike out after winter storage is to spray some fogging oil back into the cylinders and remove the rocker arm caps and douse everything. 10w40 motorcycle oil would be appropriate for your location and because its still cold. 20w50 is the norm but I wouldnt use it if I was riding below 40 degrees or if youre still getting overnight temps below freezing.
 
Welp I got the bike started and it purrs like a kitten. Took a long while to get it to warm up, but I'm sure that normal for a bike this age that hasn't started in god knows how long. Check out the video below!


After I let the bike warm up a bit I checked on the status of the drivetrain. I pulled in the clutch and kicked down into 1st gear, and as soon as I did the back wheel started spinning, even with the clutch handle compressed. I kick it up into 2nd-5th and it just spun away even within no clutch applied. I'm sure this isn't normal right? I got a feeling that something with the clutch is fubar'd. Anybody got any ideas on what it could be?

Another thing is my petcock is leaking pretty bad. Do y'all recommend using a rebuild kit or just buying a new one?

All and all it feels good to get it started so I can move on to the next task of this project.
 
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Check to make sure your clutch is properly adjusted, should be in the manuals that are sticky'ed at the top. Mine still spins a bit while on the center stand, but it's not noticable when the bike is on the ground. Sometimes though, clutch plates can get stuck together after a long time of sitting. If you can take it for a test ride (assuming everything else is functioning), try to do a good stop with the rear brakes and sometimes that can break it free. Otherwise, the plates might need a rebuild, which isn't too hard.
 
Check to make sure your clutch is properly adjusted, should be in the manuals that are sticky'ed at the top. Mine still spins a bit while on the center stand, but it's not noticable when the bike is on the ground. Sometimes though, clutch plates can get stuck together after a long time of sitting. If you can take it for a test ride (assuming everything else is functioning), try to do a good stop with the rear brakes and sometimes that can break it free. Otherwise, the plates might need a rebuild, which isn't too hard.

Unfortunately there will be no test rides anytime soon. The brakes and tires are are roached! I'll study up on the clutch adjustment tonight, thanks!
 
You can sit on the bike and apply the brake and put it in gear. My bike might get a little sticky when it hasnt run in a while. While the bike is warming up I will give the clutch a few pulls to get some oil in there.

When the bike sits, most of the clutch is not submerged in oil. It dries out after a while, no big deal.
 
You can sit on the bike and apply the brake and put it in gear. My bike might get a little sticky when it hasnt run in a while. While the bike is warming up I will give the clutch a few pulls to get some oil in there.

When the bike sits, most of the clutch is not submerged in oil. It dries out after a while, no big deal.

Thanks Mike!

Got an advice on a leaky petcock?
 
I ended up replacing the vacuum driven petcock with a gravity style one and it looks as if the leak is gone!

I'm looking to replace my choke cable and assembly and cable with a pull type located on carb. Anybody got a clue if this is even possible?

Also the weather has taken a turn for the worse here in Chicago, so not much wrenching lately. But I have been ordering parts like crazy!
 
order parts is so key! I'm building a minibike right now and I've been stocking up on online parts orders during the quarantines. I have no idea if that style of choke would work for you but I expect you'll get an answer from a senior forum member in short order. Best of luck on the remaining spring build!
 
OK! So the nice weather is finally here in Chicago ...kinda (supposed to be below freezing tonight)... now it's time to start with the tear down and rebuild.

After I got the bike to crank over (which was featured in a post above) I figured I'd move onto the front end.

First step front end tear down. I had already stripped down the damaged headlight mounting brackets to make room.

Got the bike on a super pro center stand lol


Then the front wheel and fork tubes came out




After the front end was stripped it was time for the rebuild and refurbish

Luckily the fork tubes are in decent shape. The top plugs came out "easily" compared to some of the stories I've read on here.



also the oil wasn't in bad shape either. Hard to get a pic of how clean the oil was, but if you look at the drip on the fork tube you can kinda see



filled them with new oil and then prepped them for paint



paint drying, plus guest appearance of my dog Lucy



now onto the front wheel and brake rotor

I had to use some PB Blaster and rubber mallet to get the rotor off



prepped, taped and ready for paint







taped off and painted up the rotors with hi temp paint as well



finished wheel
 
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ah man I can't see the photos. I really want to see this post! Anyone have an idea how to get them to load? Just looks like this for me
upload_2020-5-7_15-42-36.png
 
Now on to the reassembly of the front end

You can't put freshly painted parts on some dusty a$$ yoke and triple tree, so on to more prep and paint


turned out nice!



now on to the instillation of the handle bars



now the fork legs with new gator boots are back on



Front wheel back on and bike back on the ground.


I also installed new fork mounted headlight brackets with during the install. The whole front end I'm in love with, but I go back and forth on the tracker bars.

Let me know what y'all think!
 
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