Motorcycle Forum banner

1 - 2 of 2 Posts

·
Registered
Joined
·
18 Posts
Discussion Starter #1
I have a 1978 Honda CB400TII that inadvertently turned into a project bike. After a month if getting the engine apart and back together I finally started it and 3 things happened:
1: Oil started leaking from the gasket around the bottom of the cylinders. And not just a little. It was enough for it to start pooling on top of the crankcase and drip down the bottom. It's not leaking on all sides just the right and left sides. I replaced the gasket when I put it back together so I know the gasket isn't bad. The only thing wrong I can think of is that the old gasket was stuck on pretty good and I couldn't get all of it off but I did for the most part. I'm hoping that maybe just putting a bit more torque on the bolts will fix that problem.
2: While the bike did start and idle, when I rolled on the throttle even a little it would sputter and die. When I got the bike it had trouble idling but would be fine when I had the throttle open, but now I've reversed the problem. The only thing I can think of is that I replaced the handle bars to make them lower and for some reason it made all the cables tighter and to get the throttle cables onto the carb I had to take off about a third of an inch if the cable housing. I did get the engine to rev after about a minute of leaking and letting the engine warm up, but...
3: Smoke started to come out of the top of the exhaust headers. I'm really hoping it was just the paint I put on them was curing (or even burning off as long as it wasn't the actual engine that was smoking) that is made for high heat or just the oil that might have been dripping on the them burning off.
Any advice would be helpful!
 

·
Registered
Joined
·
1,133 Posts
gasket material that is left on a surface is the major cause of leaks. always remove all stuck gasket material with a combination of solvent and a scraper. what you want is a polished gasket seat. The smoke on the headers? There were probably header seals in the head that you need to get out before you put the new ones in. It usually takes a special chisel tool to remove them, I have removed one with a screw driver, but I bent the screwdriver getting them out.
 
1 - 2 of 2 Posts
Top