Newbe here. So I have this problem, what next?

[exess4]

My contribution to the community so far is what NOT to do; I suspect this to have gone unheeded after reading a recent post about someone trying the same thing - Kickstart/spring problem and having the case cover off. Although with clutch disengaged THIS is much less likely to happen:

After getting the bike in April (using part of my tax refund) I planned on getting her running w/ minimal funds and mechanical fuss. Due to unforseen and unmindful circumstance a COMPLETE tear-down was obviously, without question a necessity.

Turns out for the better since to do so, with no prior rebuilding exp. this idea was entirely daunting.

So now, recently newbie to the blue-collar working world, I've torn it down and ready to comlpete the parts list compilation and start shopping for bearings, rings, seals and whatever I hopefully don't forget.

BTW, I never did get a Clymer's so big love and thanks on YOC for the stickys, the Pioneer, and to YamaGod-Man for PDF of the Haynes.

Not to mention all the mostly great, sometimes interesting, advice.

I'll have loads of Q's and hopefully something to contribute in following weeks/months. Original goal was to be motoring by early July (I won't say the day), and now it's changed to sometime before the snow.

A couple quick questions: What is the safest and best way to clean the barrels?

Best gasket sealant for joining the case back together? (posted this question elsewhere (Bar hop)

But first things first! How effective, what method of welding, what questions to ask, what to be mindful of when I go to have above picture-puzzle pieced together? Regards and thanks!!!!!

[DTGordo]

As you've got the case apart, you could take it to a welder who should be able to tell you if they can do it or not. Some welders are magicians I reckon so hopefully you can that sorted.

Gordo

[wildturkey]

while checking out the welders for that option you should check your local craigslist and check ebay frequently and people are parting out these bikes or selling parts bikes whole quite often.

I am not sure about your exact model but use the cross-reference guides to find out if the your part was used on something else first or again.

[wildturkey]

If I have this right we are looking at the Crankcase of the XS400-2E 1978. according to http://www.cmsnl.com/yamaha-xs400-2e-1978_model8665/partslist/B-09.html the crankcase assembly # is 1L91510001. You take the first three digits "1L9" and look it up in a cross reference guide like, http://www.johnnystoybox.com/yamaha_parts_cross-reference.htm and you find out that the first bike the part was used on is the xs360d.

I could be totally wrong on this but when I do the cross reference for parts on my bike "77 xs500" it all seems to make sense.

good luck

[jrhendryx]

I had a KZ 305 that ran super lean and blew a hole in one of the pistons, requiring a full tear-down.

I used a sealant called 1190 I think... It's grey, and dries pretty fast. It's great stuff. Oil-resistant, and will still bind the case halves together, even if you cant get the gasket surfaces perfectly clean.

As for cleaning the barrels, I took mine (since I had it apart anyway) to a small local bike shop to have them honed prior to putting new pistons and rings back in. You will want to make sure that the barrels are still within clearance tolerances for the pistons/rings you have and that you don't have to bump up a size before putting it all back together. I think it cost $35 for them to do a wet honing on both barrels, and they shone like mirrors.

Good Luck!

[exess4]

As you've got the case apart, you could take it to a welder who should be able to tell you if they can do it or not. Some welders are magicians I reckon so hopefully you can that sorted.

Gordo

My first post on this problem, when still distraught and dismayed was assuring enough that it can be done, but yea "some welders" is the key, need to ask the right questions, the right welder to get it done right. Thanks for the resp!

If I have this right we are looking at the Crankcase of the XS400-2E 1978. according to http://www.cmsnl.com/yamaha-xs400-2e-1978_model8665/partslist/B-09.html the crankcase assembly # is 1L91510001. You take the first three digits "1L9" and look it up in a cross reference guide like, http://www.johnnystoybox.com/yamaha_parts_cross-reference.htm and you find out that the first bike the part was used on is the xs360d.

Excellent info, thanks for the help. I have my own theory though on the 2 parts of the Crankcase having been broken in together, worn in and warped and so on for the life of 15,000 miles that I prefer not to replace just lower half of case. Plus I'm just plain cheap Not sure on relevance of that idea, but am still cheap, convinced it's fixable.

As for cleaning the barrels, I took mine (since I had it apart anyway) to a small local bike shop to have them honed prior to putting new pistons and rings back in. You will want to make sure that the barrels are still within clearance tolerances for the pistons/rings you have and that you don't have to bump up a size before putting it all back together. I think it cost $35 for them to do a wet honing on both barrels, and they shone like mirrors.

Good Luck!

hmmmm, this "wet honing" sounds like just the ticket, not familiar enough to have known of that. Definitely to consider! I really was not planning on taking the bike or any parts to a shop with exception of tires and wheel spokes. Still time to look into that, probably won't be quite that price I'm thinking but maybe close to that and sounds well worth it if there's not a simple effective positively safe way to get done myself. Many Thanks!

[drewpy]

that snapped kickstart boss is a common problem due to newbies stabbing at the kickstart, not letting it mesh with the gears first.

your right in saying that the halfs need to be together as they are machined as a pair, as are the head and cam cover!

xs360, 250 and 400 crancases are all the same, may be able to snag one cheap somewhere.

when you say clean barrels I take it as the finned outer, if you mean clean the bores, then honing is the way to go, you can do it yourself by hiring the honers and using a drill

[exess4]

Used wrong terminology, I guess. Barrels - was referring to cylinders specifically and a local bike shop said only $20 for a crosshatching/wet honing cleaning. I like.

I think that Wildturkey prob. meant to replace entire case, upper and lower half, come to think of it, except I want to keep the same engine # on it.

The same local shop coudn't get Wellseal (preferred that) but bought Threebond 1194. Thinkin' the right stuff, and instructions to apply as thinly as possible. (apparently it is the replacement of 1104 due to lead content).

Haven't had time to talk to any welders about problema primera BUT what about this idea: have used this stuff on an old car for rust holes in the muffler and it hardens like, well . . . steel! The thought has occurred and am tempted to try it out although I might have forever regrets if it goes awry.

Then there's also this stuff, Devcon metal patch

Probably not such a great idea to even entertain

[jrhendryx]

The same local shop coudn't get Wellseal (preferred that) but bought Threebond 1194. Thinkin' the right stuff, and instructions to apply as thinly as possible. (apparently it is the replacement of 1104 due to lead content).

Yep, Threebond 1194 is exactly what I used. Great stuff.