crxnfx

Okay gear heads, thinking caps on.

So my ancient 96 Seca 2 has some problems with the engine and I want to get them fixed. I'm on deployment right now, so its not like I could fix them right now, but I will when I get home.

first and foremost, the bitch burns oil. Like a lot. it blows blue smoke, in the form of a light haze (sometimes white) from the exhaust when I start it in the morning. I guess through acceleration, it blows smoke as well. from what I can tell, my rings are either nearly gone or gone. Is this a true statement? I have checked for oil leaks (when parked) and there are none. Is there anything else I can check to verify this without ripping it open and replacing the rings? It has about 26k on it, which is much too early for ring replacement, but I have a feeling that it spent some time at redline with a previous owner.

It only has about 56 horsepower, but it feels like it doesn't have any. acceleration is lumbering but it does climb, compression test on the carbs is good- they all read the same and within tolerance according to mister manual.

is there anything I should check before paying $50 for rings when I get home? Thanks in advance.

Chino

spark plugs?

98formulaLS1

duh!!!! do a compression test on the cylinder!!! Go buy a compression tester from the autoparts store. Thread it int your spark plug holes. Then, crank over the engine with the fuel lines disconnected. This is a sure fire way to test your piston rings.

skr00zloose

and valve seats, and head gaskets, etc.

anyway, if you're gonna do the rings, while you have the motor apart, do yourself a favor and replace the valve guide seals, check the valve seats and lap them or have them re-done as needed. I shouldn't have to say it, but I will anyway, DON"T try and re-use the head gasket, or wrist pin clips if you take the pistons all the way out.

I have a compression tester if you want to borrow it when you get back.

If you're burning oil, you might as well just rebuild the whole top end, or you might just be putting a bandaid on the problem. Do it once, do it right.

rollingstock

+1 and dont u have to pull the rods to get the pistons out?.. thats rod bearings, and whatnot.. id send the crank off... probly better off buying another motor or a whole bike haha

skr00zloose

nah, that bike doesn't have upper case/cylinders like alot of sportbikes, it's like your KZ's, the cylinder block comes off, no need to tear into the bottom end.

98formulaLS1

no way...unless your incompetent.

skr00zloose

troof...

that seca motor is about as basic as it gets. No offense, but it's pretty much a 4 cylinder lawn mower engine. Even if you've never done a top-end rebuild, if you wanna learn, that'd be a great motor to start out on. With the exception of maybe getting the timing way wrong, you can't really screw it up if you take your time and pay attention to what you're doing (and get a service manual)

crxnfx

thanks for all the input. I just checked the valve seats and they are right within tolerance. Since they are not adjustable- I'd have to buy new ones and that puts me right at the mark for over or under. I'll stick to what I have.

as for the engine- having built at least 4 motors I know not to the old head gasket or wrist pins and to replace as many of the gaskets as possible with the motor open.

I'll buy a piston compression check when I get home and check out the piston compression for sure.

as for buying a new bike: why? I can rebuild this one.

skr00zloose

uh, maybe you got confusted, valve SEATS aren't generally replaceable on jap bike heads, nor are they adjustable, and you'd have to pull the head off to even check them.

By seats I mean the point of contact in the cylinder head where the mushroom end of the valve meets the head, in the combustion chamber. You don't have many miles on the motor, so they're probably fine, just lap the seats, put the valves back in, and they should be good to go.

when you do a compression test, if any of the cyliders are low, you can then do aleak down test. If you hear air out of the carbs or exhaust, the valves aren't seating properly, if you hear it out of the crankcase vent or the oil fill hole, it's more likely rings.

that may sound confusing, but I can explain it in more detail if ya need it. Just don't have time at the moment, gotta go back to the shop and load a crapton of bikes in the trailer for sturgis.