Low Power

[Joshwuh]

I bought my '77 XS400 stock. It was missing the exhaust baffles so it was kind of like straight pipes and I put pod filters on (didn't rejet). It had a lot of torque on the low end and when I hit 7k-9k rpms it was like I hit a turbo button and power really kicked in the only problem was that it overheated on highway trips over 20 miles. Now that it's spring I bought some new baffles and put them in and noticed a substantial drop in power over the whole range and I can't get past 8k rpms on most days. (on a side note one of the baffles actually didn't fit right so there's still pressure coming from the exhaust collar area) I'm planning on rejetting but I'm curious if this will give me back the power I had. And if not then would a rejet with the "straight pipes" prevent overheating if I were to remove the baffles?

Regarding low end power my mixture screws are at 3.5 turns each (I know the misfit baffled side should be different and I'm experimenting right now to see what gives the best results)

Thanks for any input/advice

 

[Joshwuh]

After doing some googling I read that apparently it's abnormal for an air cooled engine to overheat at higher speeds. Also, this could have to do with the ignition timing is set too advance and the tappets are tight? Any input? Also, what are "tappets"???

 

[drewpy]

no tappets in the sohc, that term refers to the old OHV engines where the camshaft lay near the crankshaft and mushroom headed "tappets" rested on the cam and pushed a rod (pushrod) to the rocker arms and hence to the valves.

everyone calls them tappets now though as you still adjust the rockers

 

[XSLeo]

With the pods and "straight" pipes the engine is probably running very lean. This will make it run hot.
Leo