Another Newbie

[jed74126]

New to the forum and new to the XS400. Just purchased an 81' XS400 Special II. Bikes I have owned, 03' Suzuki Savage 650 (purchased new), 05' Yamaha V-Star 650 (second bike purchased new), currently own a 08' Yamaha XT250 (purchased used) and now the 81' XS400. A little about me, my riding style is adventure/sight seeing. That's why I went from cruisers to a Dual Sport bike. Nothing wrong with the cruiser's, I loved them. Especially my V-star. But I couldn't see taking the V-star down a seasonal road, especially some of the seasonal roads I've been down with the XT. Some of those roads literally turned into goat paths. Anyway, my intentions for this XS400 is to turn it into a scrambler/tracker type bike, not really to take down "Goat Paths" but something that I can ride on the paved roads and the occasional dirt roads/ seasonal roads. I'll save the "Goat Paths" for the XT.
I have been reading posts on this forum for about 2 weeks now and found it very helpful with a lot of good information. Hopefully sometime here in the future I can help add to it with my experiences with this bike. You all seem like a good group of people.

Thanks,
Jed

 

[Lepp]

I really like this site as well and have learned a hell of a lot from these guys this street thing is new to me I been on dirtbikes my whole life but I’m catching on quick and my xs is turning out pretty sick

 

[jed74126]

Awesome Lepp, you got any pics of your XS?
Sorry to just post one day and not come right back to update. Been busy with this bike and attending my daughters softball games. Was having a problem withthe bike stalling on me after about a mile. Wait a minute or 2 and it starts back up and goes for another mile. Cleaned the carbs a couple times, complete and thorough tear down. Finally found the problem. Previous owner or someone he knew had put the tank cap vent back together wrong. Re-assembled the cap the right way and took it for a ride. 20 miles and no problem other than a slight surge at steady speeds. Had to wait for my synchronizing gauges to get here and sync the carbs. I know i need to re-jet due to the pod filters I put on. Tonight I shimmed the needles up with a washer on each(.020) and it helped a little, probably could open up the idle mixture screws another half turn each might help a little more but going up 1 size on the pilots and 1 or 2 sizes up on the mains is probably a better idea. It really does run really well other wise. I did get it inspected Monday.
I just want to make sure everything is in working order and reliable before I start stripping parts off and scramblizing (is that a word) the bike.
Question: was there an 18" rear spoke wheel with drum brake on any of the XS400's? or does anyone make a rim and spoke kit where i could use my existing rear hub to make it an 18"? I found only one dual sport tire that would fit the 16" rear wheel I have now. Bridgestone TW40 and it seems nearly impossible to find. Everyone seems to be out of stock, and they don't have an 18" front tire to match it.

 

[Lepp]

I’m pretty sure mine has a 18”spoked drum wheel on mine but yeah I think that picture of mine uploaded on here for ya if not let me know but yeah I been looking at getting some knobby or dual sport tires for mine my buddy I went to MMI with has a 1972 xs650 that has the mag wheels with the knobbys and I think it looks rad as fuck

 

[Lepp]

This what it looked like when I first got it and a picture now after I threw the clip on bars onto it. I am thinking bout taking off the instrument cluster up there too and everything cause I use my phone as a speedo anyways and subs just wire up a little green light for the neutral indicator

 

[Lepp]

Nvm I was wrong mine are a 16” as well I’m not sure about if they make a 18” for our xs but Try Motosport.com for your tires I’ve found a few nice dual sport tires there

 

[NewHavenMike]

Xs360/xs400s came with 18” spoked drum rears. I have 18” front and rear.

Get some plug readings before you up jet. Id go back to original filters unless you can get ahold of the old K&Ns that were made for our bikes, keep the H-pipe too...

I had to go down 2 jet sizes on my bike even with aftermarket mufflers. Going up is not always the fix.

I like Heidenau tires. They may offer dual purpose tires too. I use their K34s and they look good

 

[xschris]

80-82 sohc xs400's used 16" rear tires.

 

[jed74126]

Plugs with stock exhaust, stock jets, needles shimmed up .020, and Alpha Moto pod air filters.

 

[jed74126]

This is the plugs after re-jetting pilots up 1 size to a 45 and mains up to 137.5 . Looks rich on the left. Idles great, seems to rev up good but still surges slightly at cruising speeds. Has no problem accelerating and getting up to speed quickly. Last night I pulled the carbs and checked the needle heights. Left side measured. 015 higher than the right. Both needles have the same #'s on them (5GZ9) and I had them shimmed exactly the same. Found that from the tip of the needle to the clip groove was slightly different. So I adjusted the needles so both are at the same height now and re-assembled everything. Getting ready to take a ride now to see if it helped. BTW pilot screws are at 2.75 turns out, seems to idle best at that setting. Wish me luck! Lol

 

[xschris]

I would put the stock H-pipe and air filters back on and ditch those pleated pod filters. Those will cause all sorts of turbulence and make for poor running with our type carbs. If you must use pods, black foam uni's on the stock H-pipe will work ok.

 

[jed74126]

My stock H pipe has a tear in the rubber in one side. A new old stock I found on Ebay was $45 for one side. I went with the pods because they were cheaper and ultimately with my build the side covers and battery box are going away. I do understand though that those pods would create a turbulence that will make it hard to tune these type of carbs though. Took it for a test ride today and it is much better since I got the needles at the same height. Just got back from the ride and still have to pull the plugs to see how they look. I did put a new set of plugs in last night after I set the needles.

 

[Lepp]

I built a custom box for my battery make for a lot more room right there

 

[Lepp]

 

[Lepp]

I had to adjust each cylinder a little different than the other cause that how my right cylinder plug looked like running too rich so I just backed out the air screw 1/4 turn r so n they look much better

 

[jed74126]

Here is the 34 mile results

 

[xschris]

Still looks very rich. Tip is your pilot circuit, top half of the porcelain is your mid range and the bottom of the porcelain is your main jet. When you look at your plugs those areas will give you an idea what is in need of adjustment. Tips should be almost clean with a bit of color. Porcelain should have very light tan. the only black should be on the outer ring of the metal screw part of the plug. Sometimes a grey or brown also is fine. If you want to get more into it you can take head temps of the motor with an I.R. gun. Next to the plugs on the exhaust side of the motor after a good 50+ mile run at highway speeds on a warm day a stock sohc xs400 will get to about 265-285*f

 

[jed74126]

That explanation makes more sense to me. Thanks chris. I took the .020 shims out of the needles putting them back to stock. Took it for a 40 mile ride this morning and it made a big difference, way better. Just pulled the plugs and they look more like what you described. I think I also need the turn the pilot screws in a little. Maybe a 1/4 to 1/2 turn in. Feels a slight bit rich at cruising speed. Thanks again!

 

[jed74126]

So here is what I come up with to clean up the rear end still using the stock rear fender.

From this.

I also replaced the chain and sprockets with and EK oring chain and JT steel sprockets. Mufflers are on their way. Next is to work on the front end.