Cylinder head paper weight

Xjers:

I assume, since my Seca 400 doesn't use cam bearings, that if the cam bearing surfaces are messed up the head is now a nicely machined paper weight?

I'm sure there was some reason Yamaha decided to spin the cam directly in the head surface ($), but it sure would have been nice to just change bearings instead of having to search for and fork over big $$ for a good used head.

Herb

 

take it to a machine shop for a second opinion

 

As far as I know, the early KZ Kawasakis were the only Japanese engines to use dedicated cam bearing shells. I think a used head is the cheapest route for you.

 

Be more specific about the "Messed-up" ... maybe you have some options!

 

Can you post some pix showing the "messed up" portion?

 

I do believe that competent machine shops can set you up with bearing shells provided the head can support the machining, bearing shells of that size are available, and the cam isn't toast. A second opinion is in order. Used head isn't a bad idea either.

 

XJers:

Thanks for all of the responses.

I don't have a picture readily available, but one of the bearing surfaces on the exhaust cam is really rough and chewed up, as a result of my recent oil dump episode. That area of the cam has also worn through the plating, so it's history.

I contacted Bore-Tech on the internet -- an apparently respected and advanced motorcycle engine machine shop, and received the following response:

Hello Herb,
At the present time, it would be more cost effective to find
another head if the cam bores are damaged. Special tooling
would need to be made to do the repair.

Regards,
Bill Moeller

I haven't completed my tear-down yet, I'm also pretty sure I've got cylinder and/or piston damage in one cylinder.

A fellow on e-Bay has a head and cylinder for sale, but the head looks really weathered (rusty valve pucks) so I'm not keen on that.

Since pistons are no longer available anyway, and new cams are rarer than gold, I am switching my efforts to trying to locate a good used engine.

Wisconsin Cycle Salvage has four engines, ranging from $125 - $250, with the price based on measured compression. Shipping down here would add about $150 to that. I'm very uncomfortable going this route, since what I pay $300 - $400 for may be little better than what I have, but I don't seem to have a lot of options.

Sorry I haven't been posting lately, but I've been in somewhat of a depression since realizing I trashed my pristine, low-mileage engine through an ignorant mistake of my own doing (I mis-read the torque spec of 11 ft. lbs. for the oil filter cover as being the spec for the drain plug).

I just spent $300 on tires and chain/sprockets, and I don't have money lying around to throw away, so I'm not sure when I'll actually be buying an engine, but that is the plan.

If anyone has experience with buying used engines, or Wisconsin Cycle Salvage in particular, I'd appreciate hearing from you.

Thanks again for taking the time to reply.

Herb

 

i live bout 34 miles from salvage yard. I have bought a few items from them. they take every thing apart lable and put in shelves and such. you really have to trust they marked stuff correctly. They also build harley bikes (more of there main stay i believe) i think they sell every thing else to support the harley builds (just my opinion) But if you know what your looking for or at , I have no negatives as of yet.

 

Most engines these days use plain bearings in the aluminum head. Aluminum isn't a bearing material though so the bearing surface is actually the film of oil present when it's running but the oil drains off when it sits, then it's dry for a second when you start it and the surfaces touch, so some scarring is normal. Also, if the engine is run low on oil or overheats and the oil pressure drops to zero it will damage the bearing surface, which is a reason for everyone to use an oil cooler.
If the surface isn't burned or badly galled and moving parts still turn smoothly when oiled it may be OK. If it's too badly worn you will get a lot of loud knocking and other noises.

 

Will a 550 Engine bolt-up? I bought a 550 and was athinking about starting to restore it over the Winter.

Now, I don't have the room, unless I sell my 750 or 900. That ain't happenin'!

I had the engine "running" for a few minutes. Mostly on starting fluid, just to see if it would 'Go' ... it goes!

I'll give you dibs on the engine until you figure-out what you're going to do.

 

Used engine is not a bad idea. Low compression on a pulled motor could be a number of factors (some of which may work to your favor). I plunked down $150 for a used motor (with passable compression according to him, he was fronting for a yard) from a fellow in Utah to ship a 750 Seca motor to Los Angeles. Popped the sump and was treated to an absolutely beautifully clean motor. I went and did the compression test myself with my calibrated compression gauge and got better numbers than he quoted. Roll of the dice on that one but as I mentioned earlier, play like your going to loose it anyway. Do your homework, check out histories, ask around. Best thing you can do. Consider an upgrade such as Rick has suggested. Cheap and a lot of fun to boot! $150 for a used motor is reasonable. Shipping will cost but in the end if he's got what you need, start saving your pennies. The rusty head on flea-bay is a last resort as I expect you'd have some machining needing to be done to make it run happily. That or the poor sap just happen to be unlucky enough to leave it outside for a few nights last year. Might clean up nice and easily. Tough choices, I'll pray you get what you need. Best of luck to you and start saving up, Rick needs the room.

 

Robert, Rick, Steve, Chevy, et al.:

Thanks for the thoughts, offers, opinions, guidance, and prayer.

RickO- thanks for the dibs, but mine is the baby Seca (400 twin), and I don't want to even think about what I would have to do to the frame to make a four work! Looks like you'll just have to add a room for your latest project!

With the engine as a stressed member of the chassis, my only options are the 400 Seca or Maxim from '82 or '83 (and maybe '84 in Canada).

So far I've found the four engines at WCS for $125-$250 and one at a salvage yard in Canada for C$500 (!). Other than the compression checks done at WCS for pricing purposes, the condition of these engines is anybody's guess.

One other possibility is a 400 Maxim I found for sale by a fellow in Ontario for $200. He was selling the entire bike, which he said ran well but had a broken starter chain. He's including the new chain with it. Since I can't pay to ship the whole bike, I asked him if he would pull and crate the engine for an additional $50, if I arranged shipping. He said that sounded agreeable.

So while I'm counting pennies and making sure I'm not dipping into the kids' Christmas, I'm trying to decide which path to take. The Canadian salvage engine is obviously out, but I haven't decided about the others.

I'm leaning toward the Maxim engine from Ontario, since I at least know it's running (assuming the fellow is truthful, which I believe he is).

I tried to get more details about the WCS engines, but only got a series of one or two-word replies, which was kind of a turn-off for me.

So anyway, that's where I stand right now.

Thanks again for taking the time to help in my moment of pain. :wink:

Take care-
Herb