I have an 88 with a Duke. Over the weekend I replaced the exhaust manifold due to a rather large crack. While I was at it I changed the O2 sensor and cut out the very clogged cat. Now i am getting valve clatter with light acceleration. Any ideas?

Pull the valve cover and check the lash sounds like all that back pressure or the lack of it depending on the crack has pushed it off. I don't know an easy way to check the valves.

Could just be an exhaust leak. They sound like a bad lifter/valve or bearing.

J.

quote Originally posted by jaskispyder: Could just be an exhaust leak. They sound like a bad lifter/valve or bearing. J.

No leak. It is vale clatter. Thanks for the thought though.

The duke clatters like an old diesel truck when it gets worn, the exhaust leak probably masked that until you fixed it.

JazzMan

Is it a fluttering sound? Like detonation? My duke did that when the EGR wasn't working right.

quote Originally posted by Steven Snyder: Is it a fluttering sound? Like detonation? My duke did that when the EGR wasn't working right.

X2

quote Originally posted by Steven Snyder: Is it a fluttering sound? Like detonation? My duke did that when the EGR wasn't working right.

X3

You shouldn't have any valve noise while the engine is above idle that isn't there at idle. At idle the oil pressure is lowest, and therefore more likely to allow a lifter to bleed down if not lashed properly (and oil pressure is very low).

EGR valve seems to have been the issue! What a great site!

Heh, lifter chatter is normal on an 88 Duke if you haven't rebuilt the engine...they still keep on going, and going, and going though :P Tough engines, if a bit anemic.