What did you do with your XS today?

Got some replacement LEDS off Ebay for my speedometer & tach. Less than $5 shipped for 2 and boy are they bright. Highly recommend them. Probably should have got 2 more to upgrade the 3 middle indicator lights.
 

Attachments

  • xs400j bulb.jpg
    xs400j bulb.jpg
    5.6 KB · Views: 417
Let us know how those LED bulbs work out in the long term. I haven't had more than a couple weeks from the cheap ones before they start failing. Poor quality solder and the vibrations of the engine...
 
Compression test.

After taking a ride around the block to warm up and perform an oil change a couple weeks ago, I found the bike running rather rich. Apparently, the night before, the carb float valve stuck and drained into the crankcase, which explains why the tank was lower than I had expected. It did make draining the old oil very quick though. So, I carried on...new filter, fresh oil, couple slow turns with the kick starter to get the new oil acquainted with it's surroundings and started her up and took it to normal operating temperature. So, coming around to today, I did a cold compression test with good results, considering that the engine was "seized" when I got it a year ago and have done no internal engine work. Right side: 165 psi, left side (threads are a little buggered and I couldn't get the tester in all the way to seat the o-ring): 158 psi. Now that there's fresh (and properly viscous) oil in there, we're back to the usual; running decent / possible intake leak forming.
 
Took my road test and passed! I've now got my full motorcycle license.

Also spent a bit of time troubleshooting bouncing/sticking speedometer and tachometer needles. Took the cables out and greased them, and re-routed the lines to get rid of some of the tighter turns. Seems to be working fine now.
 
Let us know how those LED bulbs work out in the long term. I haven't had more than a couple weeks from the cheap ones before they start failing. Poor quality solder and the vibrations of the engine...

I put some (1157 brake light bulbs also) in my 82 that I got from walmart last fall and after 1000 miles they still work:shrug:
 
UYoSN07.jpg

I got my home made rearsets excruciatingly close to finished last night. They're hilariously overbuilt; if I get ambitious I might downsize everything from M8 to M6. I need to cut a longer linkage for the shifter, it's currently too short to allow the correct range of motion and a comfortable toe position.
 
Replaced the carb boots. I'm not sure if the old ones were "bad", but they did have cracks on the outside and aren't very expensive or difficult to replace, so...why not? And, since the carbs were off, it gave me an excuse to quickie inspect and clean them too.
 
Last weekend:
Took apart the carbs, because the left cylinder wasn't getting any fuel. They were full of dirty rust sediment, so I decided to ditch my temporary fueltank and prep the big one.
Inspected and cleaned the petcock, checked the vacuum function, and attached it to the manifold, cut a fuelline to size and voila, looks factory standard.
Meanwhile, I spraypainted the steel bits on the carbs because they had started rusting already.
Everything back together, I couldn't get a decent run out of the engine, so I decided to check the timing, which I adjusted some time ago. Turns out the left was somehow firing early, which explains the blowbacks. Set it all back to spec with extreme care, kick it round and round, but no music. Eventually around 11pm, I found the culprit, a faulty ground-wire.
I try again the next day. Nothing. Check timing, way off, I'm going crazy, set timing, try to run it, fail. Have dinner, come back to a cooking ignition-coil, curse myself, check for sparks, find spark, try to start, fail, spill oil all over the pavement, go absolutely freaking MAD.:banghead:
When it does run, only on full choke and it dies instantly with the slightest amount of throttle....
Abandoned the bike and relaxingly built me a seatpan.

Not exactly a succes story but all work is good work I guess.
Next plans:
- check manifolds for leaky attachment, maybe get new ones as these are all cracked up on the outside.
- Check engine advance for wear (xs650 seems to have a spring-issue, same on an 400?)
- Maybe get some new contact breakers
- Try and get it running for dynamic timing
-Build a seat
 
Got the rear fender, seat and turn signals off, getting ready for mock up mode.

Ordered some clip on, head light brackets and grips. Contacted Ian holcott over at twin line about making a seat for it. He built my cb550 seat and have been a huge fan of his work since.

 
Washed the mud and road grime off the bike from a camping trip this past weekend. :thumbsup: Went to a large cruise night and didn't see another XS400. Though there was an XS650 in attendance. :shrug: And, as usual, had a number of people ask me what my bike is/was/started life as?... :D Then rode it home like I'd just stolen it. :bike:
 
Took a break in between putting cab corners on my truck and threw my clip ons on real fast. Waiting on my headlight brackets and then I'll button up everything up front

 
Cleaned and tweaked carbs, h-pipe & air boxes a bit. Also got my retro headgear all setup and ready to use. The helmet even matches my bike! :D

full
 
Went on a road trip from Ottawa down to Burlington VT and back over to Lake Placid. The bike ran beautifully, even with two of us on it, a backpack on the back, and another one strapped to the gas tank!

It still doesn't like the 1200-2000 rpm range, though, especially when it warms up after some highway riding. Makes it annoying to pull away from a light (sometimes takes a few seconds to get the rpms from idle to above 2k). I've checked for vacuum leaks but can't seem to find anything... 3rd time's the charm with cleaning these carbs, right? Anything else I should check?
 
JaredK,

If the rpms climb high and want to stay high you're lean.

If the bike bogs, the rpms refuse to climb, or performance is sluggish you're rich.

The warmer the bike gets, the warmer the air gets as it enters (it becomes less dense), further richening the mixture.

It sounds like you fall into the rich category.

What modifications have you done to the intake and exhaust? What modifications have you done to the carbs? A float height allowing too much fuel in the bowl might cause the symptoms you're describing. You may also have your idle mixture screws turned way too far out.

Issues with being too rich are generally not due to dirty carbs.

You can confirm a fat low end by pulling the spark plugs and looking at them.
 
JaredK,

If the rpms climb high and want to stay high you're lean.

If the bike bogs, the rpms refuse to climb, or performance is sluggish you're rich.

The warmer the bike gets, the warmer the air gets as it enters (it becomes less dense), further richening the mixture.

It sounds like you fall into the rich category.

What modifications have you done to the intake and exhaust? What modifications have you done to the carbs? A float height allowing too much fuel in the bowl might cause the symptoms you're describing. You may also have your idle mixture screws turned way too far out.

Issues with being too rich are generally not due to dirty carbs.

You can confirm a fat low end by pulling the spark plugs and looking at them.

Thanks bcware. The air intake and exhaust are completely stock. Valves are within spec and carbs are synced with a manometer. Float height is perfect at 3mm below the carb mixing chamber body edge. I haven't changed anything on the carbs, although the RH main jet is a #120 instead of the #117.5 that the DOHC manual suggests. Perhaps the P.O. did this, I'm not sure.

Once the bike warms up (especially after a run on the highway), the RPMs do hang a bit when they come down, yet it bogs down in the low RPM range (up to about 2k). The spark plugs look good from what I can tell. I've attached a pic.

Any thoughts?

Posted via Mobile
 

Attachments

  • IMG_20150709_183301 (Medium).jpg
    IMG_20150709_183301 (Medium).jpg
    149.3 KB · Views: 235
Apparently the reason that the manual calls for different RH & LH jets is that the design of the factory air box provides different enough airflow to the respective carbs to require it.

Maybe your P.O. was a better Japanese engineer than were the guys who designed our bikes in 1980, but I doubt it.
 
Perhaps a close inspection of the diaphragms is in order?
Is the stock air box clean? A dirty filter can cause mayhem.
Do your carbs have a rubber o-ring on the mixture screws? Is it intact?
Have you tested the butterfly seals and intake for air leaks with gas?
If your exhaust is original the baffles may have rusted out reducing back-pressure; this could have an impact.
 
Back
Top