Been a while... Updates!


XS400 Guru
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Cleveland, OH
Hey guys, I've been MIA a bit. Got called back into work the beginning of May and between that and super secret military musings, I've had no time to even get online the past month. I have a few days off again and figured I'd log in and see what's been going on.

So I took my bike to track days the past 2 weekends. Runs like a beast still, but man I can't stand riding it anymore. It's painful. The thing has tried to kill me twice now.

Just some food for thought, after putting 1500 street and track miles on it, for anyone looking to do the things I did to my bike. (see build thread if interested)-

DO NOT MESS WITH THE CRANK ON A STREET BIKE. I kind of knew what to expect from going lighter on the rotating mass, but it's a lot worse than what I expected. Being a twin, our motor naturally has a ton of engine braking, but it's manageable in stock form. It has so much engine braking now that I rarely have to use the brakes (this caused me a 'whoops' moment, keep reading). It's fine on the track, but on the street it is extremely annoying in stop and go traffic and city driving. Also, it vibrates like all hell now. Even with it computer balanced, it's just stupid.

Those craptastic Mike's XS carbs are still craptastic. I've said it before and I'll say it again in hopes that google will add this to a search and save other people money. Don't buy them, period. I pulled them off yesterday and have genuine carbs going on. They work, but only at WOT. Fine for the track, but I like bikes that can idle and have consistent AFR at any throttle position, and not go out of whack every 15 minutes.

Don't buy Chinese shocks. Mine have already had a blowout. Buy Hagons or something similar. Worked decent until the seals let the gas and oil out, but no shock should ever die after 1K miles. That's just complete junk.

I will never again use those generic ebay/etc cheapo seals. I've gone through a few sets now just to find ones that won't leak straight out of the package. I gave up and bought OEM ones and like magic, no more leaks. Had to source out a different cam seal since I couldn't find one OEM, but I made sure to grab one from a country that actually has quality control folks in their factories.

The Pamco ignition works great, no complaints.

With my frame/suspension mods, the bike handles turns WAY better than it did in stock form. It's not 'modern' good of course, but miles ahead of where it was. I think the swingarm bearings and swingarm bracing made the most noticeable difference, as the rear feels 'tighter' and less 'noodley'. Careful adjustment of the suspension seems to have played a role as well. I let a guy ride it around the track last weekend that said he used to own a bunch of old yamahas back in the 70's and 80's, and he seemed rather impressed by how it felt.

Don't be an idiot like me and ride without a rear exhaust hanger. I actually had a bracket welded on a long time ago when I welded up the exhaust, but for some reason never bolted it up. I suppose my thinking was the complete system was so lite that it would be ok. Well, take into account the insane vibration of my motor and you can guess what happened. Was riding it to work one morning and I could hear the exhaust getting louder as I rode. Looked below and could see that my mega was hanging lower to the ground. Figured my welds were crap and letting go near upper bend. When I got it home, I tore the pipe wrap off(won't be going back on, I'd rather be able to see what's going on) and I was surprised to see my welds still fully intact. The vibration and stress from the weight of the exhaust had split the pipe open on both headers right at the head. Attaching the rear bracket would have prevented this no doubt. Since I repaired the cracks/holes and attached the rubber dampening bracket, I have had no issues.

130 width rear tire is too big. I ride this thing at it's limits in turns, and I still have about 5mm of unused tire on each side. On another note, these Avon soft compound tires are the bees knees. Too bad they don't make a 120, it would be perfect.

Don't use heavy clutch springs. They aren't necessary from what I've experienced, and they are destroying clutch cable ends for me way too fast. Once again, keep reading to hear about my 'whoops' moment.

Don't get transmission parts REM polished on these bikes. I did it because all the literature says it doesn't change part tolerance, all it does is fill voids. Well my measurements prove otherwise after getting pissed off with false neutrals and ripping the thing apart to investigate. I was wondering why I had to reshim everything to line up properly when I assembled this motor, now I know why. The polishing removed a tiny bit of material, which isn't that noticeable on its own but on a complete assembled main and lay shaft it makes a huge difference. I'm getting around it by preloading the gearshift lever every shift and using massive foot movements, but it's dumb and annoying and absolutely not worth whatever minimal gain the polishing did. My theory is that the tolerances on these transmissions were a bit on the shitty side from the factory, and my mods just magnified issues ten fold.

I'm still in love with the Cone Engineering muffler. Perfect noise level when putzing around. Super loud only at WOT. I still might throw on one of their quieter cans just to see the difference, and save this open can for the track.

Oil cooler and thermostat working great. I'm convinced it is the only reason my motor has survived this much thrashing I've been doing to it.

Steering damper was well worth fitting up.

So moral of this story? Don't use heavy clutch springs. This was a brand new OEM clutch cable I put on for this build, and the ball/barrel end literally ripped right off. I'd normally blame a bad angle at the lever, but that shows up as fraying that gets worse then eventually breaks. So I really think it was the springs being too heavy and the cable couldn't take it anymore. Maybe a bad factory soldering job on the barrel end? Could be.

Well that's all I got folks. Hope you all are enjoying your rides this summer. Be safe out there!
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Oh geezzz, the track bump off sounds crazy...can't believe it stayed****t!!! At my one and only track day so far, I saw two separate rider crashes, with one needed the ambulance...both were ok I believe, but still...pretty intense reality checks. I also scared the sh*t out of myself on one corner when I downshifted to far and the bike just shuttered before making the turn....yikes! I find it really difficult to remember which gear I am in on the track and I assume that's kind of important info to have a grasp of when racing. So this Friday I'm going to make a point of working on knowing exactly what gear I'm in at all times. Any advice would of course be appreciated. I did watch "Twist of the Wrist" since my last track day, which did silly of a production as it is...solid info for sure.
Advice? Sure thing!
- you have to slow down and be smooth to go fast.
- track racing requires consistency. Repeat until perfect, then do it again! And again!
- only make 1 change at a time, regardless of what that change is.
- keep detailed notes about everything. Dates, times, places, temperatures, weights, quantities, sizes, pressures, speeds... Everything!
- speed requires focus. Avoid ALL stimulants (or other perception altering compounds), even nicotine, caffeine or sugar can cause problems. Avoid them all and drink water.
- eat well! Just be sure to give yourself an hour or so, depending on your metabolism, before getting on the track.
- warm up your body with stretching and light exercise beforehand.

Hope that helps a bit.
You also need to get rid of the fear of crashing, in racing it happens and once you get over it you'll have more fun. Lowsides are a dime a dozen, good gear and you'll just get up and brush the dust off. Just don't highside!

In regards to the rear end getting loose on you.... that's what will happen when you are right where you gotta be on the downshift. You don't want it to the point where it can break free, but a little shimmy is ok. Just watch every superbike/motogp video, they all do it, even back in the non-electronics days.

Maybe you'd be interested in a gear position indicator like I have? It's a life saver on the track. It's not extremely hard to do, but takes a little competence.
Glad you, and most of the bike, are ok! Great to read about the experience and lessons learned.