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Hey there. I just tore down my 77 XS400 engine tonight mainly because I thought there was a transmission problem due to shifting issues and the kick start was only going half way down. Opened up the crankcase and found the transmission to be perfect. I put the kickstart in place with a view straight at it hitting the gears, turned it with my hand, and again only half way. Then I noticed a little metal stopper on the far inside of the kickstart shaft that hits against that little metal lip of the crankcase. I am willing to bet that your genius that put this back together put it in wrong then tried standing on it to get it to function, breaking the holding on the inside of the case. As for the clutch push rod mine has two rods with a small steel ball between them. Did yours have a steel ball bearing?
Big R got me straight with the shifting issue ... Thanks for the tip Big R!
Thanks King
That makes perfect sense. I was leaning toward this being the result of a crash but there would be more dammage than just the kickstart boss.
Yeah there is a ball in there but it is between the rod and the thrust pice that pushes on clutch housing.
The rest came apart just as the manual said it would. The cam and followers looked OK ish. There was some scuffing on the cam bearings and one small pit on one of the followers. There was also some scuffing on the piston.
When I grabbed the top of the piston though , there was some play on the wrist pin. Even I know this isn’t right. When I removed the circlip I was able to push out the wrist pin without much effort.
So after splitting the cases and removing the crank and tranny gears I found this.
It looks like the roller bearings spun in the case.The only reason that I can figure out is that maybe some of the clutch plate/mystery metal got in the rollers and jammed them up.
This might be where the fine metal shavings came from :-\
I figure that I should be able to rebuild it But, it will be near it’s wear tolerances and I will not be able to use the kick-start. With all this though I’m not sure I want to. I really won’t be happy with it and will always be worried that it will let go on me.
I am starting to think about a new engine or at least new cases at this point.
Stick with it man, it will pay off. I am on my second set of cases and probably the 10th dis-assembly making my motor bulletproof. It will be worth it in the end. You're learning for sure!!!!
Well I started to look for a new motor. I tried the motor cycle wreaker here on the island and he didn’t have anything. I also tried one on the mainland and they didn’t have anything either.
Then one of the guys at work suggested I try the independent shop here in town. He said they had some old bikes and parts in the back.
So my wife and I went up there on my lunch hour and what was sitting in front? A black 81 XS400 and it’s for sale!
I got the guy to start it so I could hear how it ran. My wife offered to but it for my birthday. In the end though we walked away. He was asking $1900.00 for it which I thought was way too much. It looked good but the more I looked at it I could see that It had just been cleaned up very well with some spray bomb black paint and chrome polish. The other problem was that just off idle there was a chain rattle sound. Probably needed a new chain tensioner. I couldn’t justify spending $1900.00 and then tearing the engine down to find that it was no better than what I already have. Besides I couldn’t give up the bike I have.
I came across a guy on Craigslist who had a bunch of motors for sale including a XS400.
I am very weary of things on Craigslist. How do I know I’m not buying a stolen engine?
Despite this I was getting desperate so I sent him an E-Mail.
What followed was the most frustrating exchange of E-Mails I have ever dealt with. In the end it took 7 days of E-Mails to find out that he only had a bottom end and to get a price. It’s part my fault though. He had lost me on the third E-Mail but I kept it going just to find out how much he wanted for it. He wanted $200.00. If he had just came out at the beginning and told me I might have thought about it. But in the end I trusted him about as far as I could throw him.
So I happened to be on the mainland and stopped by the auto wreakers that I had previously E-Mailed. I figured it would be easier to explain what I want in person. He was an interesting person to deal with. You could tell he had dealt with a lot of guys who didn’t really know what they needed and didn’t want to pay much for it. You told him what you wanted, he told you the spread of prices depending on the condition of the part, then if you were willing to pay the price he went and got it for you.
I asked for a XS750 fuel tank. He had one and wanted $120.00. I was thinking around $100.00 and it was in very good shape so I took it.
Next was a set of cases. He didn’t have just the cases so he took me the back and pulled out a complete motor. He turned the engine over with the kick-start and it had good compression. He said he could sell just the crank for $200.00 but he didn’t want to tear it down so he sold me the WHOLE motor.
I was also looking for a different front fender so he showed me where they were and let me pick through them till I found the one I wanted.
So $350.00 later and I had a new tank, front fender and a motor. The motor was only missing the carbs,starter ,shifter lever and final drive cover. The only drawback was the cases are painted black from the factory. The serial number on the engine makes it a 1982 XS400. ;D
So I plunked the engine in a plastic tote between the seats of our mini van (my wife is so understanding) and away I went.
Thanks for the encouragement Kanticoy. It’s been a good experience so far. Now that I’m into tearing down my #2 engine the fear and worry has been replaced with hard work, sweat and a few well placed swear words.
These really are beautiful little engines. Quite simple really.
You are learning more about your bike with these teardowns than most owners will ever know. Props for sticking with it, I'm sure it is frustrating, but once your are cruising down the road you can laugh at those previous problems and punch the throttle, haha. Good luck, this I will be following.
Hmmm ... I am wondering why you wouldn't just replace the roller bearings and pistons? If the crank, trans, and all other engine components are fine (minus the kick start) wouldn't replacement bearings and pistons be cheaper/ faster? I agree an XS400 for $1800 is crazy ... look up on NADA under vintage motorcycles and you will see what they are worth. Very interested in your work ... keep going!!
Well there were a few problems. I would most likely have to repace the con rods to fix the play at the wrist pin. They are not cheap. I could fix the problem with the roller bearings by usine some Loc-Tite . Then I would have to rebearing the crankshaft and con rods. But I would still be left with some pitting in some of the gears and on the cam follower. Then there is the scoring in the cam housing. There are no bearings to replace here just the complete head. I just didn't have a good feeling about it. Too many small things that were wrong. Besides I got a new motor for only $200 ;D (as long as it turns out to be ok)
Hey King I finally checked out the NADA website.Thanks. That sure is handy. I can see that the price of xs650's and cb750's are starting to get alittle out of hand.
Not too much progress so far. i'm still tearing down my #2 engine but it looks really good. The only problem I have run into so far was a couple of siezed spark plugs. A lot of penetrating fluid and a little time took care of that. The camshaft still has the original machining marks on it except for the tips of the lobes so that makes me think that it has verry low KM's on it. Yeah there was some moisture in the crankcase from sitting so long (mixed with oil. {white goop}) but it clened up easly enough. Now the pistons still had some slight play at the wrist pin but maybe this is normal. After all the oil would have drained back to the crankcase over time. The only thing that supprised me was the same scoring where the tranny bearings go. I have since seen this in a couple of builds on this site so once again maybe this is normal? ??? I will post some pictures soon.
It has been a while since I last posted anything here but I have made a little progress. Not so much on putting anything together but I have managed to collect a lot of the parts I will need.
First here's a picture of the cam from my #2 engine. It looks like it still has the original factory machining marks on it.
Also here are the marks where the tranny roller bearings go on the #2 engine. It looks the same as the ones on my first engine. So maybe it is normal?
Here are some of the gaskets and other parts I have bought.
These are some of the tools that I picked up. I love Midland tools. The fork boots are actually shock boots from Pro Comp.The small end is 33mm and the large end is 54mm. I haven't tried them on yet but should fit my forks perfectly.
Here's some fun stuff I bought. I also got a pair of sea boot socks but don't have a picture.
I was really happy to get a pair of 33mm clipons. I got them from 250champ on E-Bay. There was no "buy now" button so I had to wait several weeks till I got the price I was willing to pay. They were a great buy At a good price.
Very cool. I'm working on a '79 XS400 cafe right now. I actually ended up with two, and I plan to tear down and rebuild the extra motor maybe next winter, and setting my build up for this coming summer with the better of the two. I'll be watching
My last post is a bit deceiving. I have actually put a lot more work into it in the last while than it sounds. I have received all of my gaskets and seals. The Athena gasket kit in the picture was a no brainer. It was way cheaper than the factory stuff. However I have read in a couple of places that the Athena base gasket is to thin and prone to leaking. So I ordered a OEM Yamaha base gasket. The Yamaha gasket is thicker than the Athena and only cost me $7.00 so was well worth the price. The seals for the tranny (main output, clutch push rod , ect.) do not come in the Athena kit so I had to order them separately.
I looked around to see where i could get the best deal. The OEM parts (except for the Athena kit) were pretty close in price. The big difference was with the seals. Bike Bandit was almost half the price. So I decided to buy all the parts from them. It all fell apart when the freight charges were applied to Canada. The freight took up most of the savings. So I ordered the parts from my local dealer instead. Same cost but OEM quality. This turned out to be a good thing. Along with the seals and misc parts I also ordered crank and con rod bearings. This is where things got fun.
It took several weeks to get all the parts as some were backorderd to Japan. In the end one of the crank bearings was discontinued. Well there is no point in changing only 2 of the three bearing sets. The dealer did give me the part # and suggested I try online. 2 days later I had the bearing coming from a dealer in the next province at a cheaper price. I should note here that the bearings are sold as a half a set, something I didn't know at the time. It cost me twice as much as I thought.
The problem started when the bearings arrived. They are ordered by taking a number stamped on the block and subtracting a number stamped on the crank. The resulting number is put in a chart in the service manual which then gives you a color. The color is changed in the parts catalog to a part number you order.
So two of the bearings had the right part numbers but the wrong colors. it took the dealer a couple of days but he found out that Yamaha uses the same crank bearings on the FJ1200. The same part numbers but with different colors. : The other nice thing was that the dealer gave me a photo copy of 10 pages that had all the engineering specs for the engine. So now I can plastigage the bearings if I need to.
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