I put this over in the enginesection, but figure I would ask here too.......
Kinda have a weird question , but here goes.... Just put 1 3/4 drag pipes on my 98 dyna I just bought.Not the one in the sig,but twin to that one.Dont know ANY history on it except its only got 16k on it,STOCK other than open K&N air cleaner and drag pipes.Its being jetted next week for the pipes and K&N, but here is the thing....startedit up, and there is ALOT more air coming out of the back exaust than the front,it that normal for it not being tuned? Back pipe "sounds" and feels like it should(the air comeing out), and the front "sounds" kind of weak...just a weird situation.....
Anyone got a clue??

 

check compression

 

just did the compression test with both plugs out,throttle wide open and plunger pulled up...front cyl. is about 119-120-------back cyl is 90 psi.SOOOO WTH could cause that? Doesnt smoke or ping(that I can hear now,lol) motor was cold by the way. .

 

Something pluggin up the pipe?

 

EHHHH..nope! Gaurantee you that...LOL. But i gota figure out whats up with the compression.....I dont hear ANY engine noises,hopefully its nota lifter bleeding down.I usually dont work on them, I just blow em up and pay someone to fix it...LOL
Seriously though, i just work to damn much and when i'm off, dont feel like working on them to much

 

Just ride it Joe and don't worry about it.

 

I don't know crap but.......the back pipe is shorter so you would feel more air and hear louder sound.

Front pipe is longer and has more c.I. To flow thru. Hence less pressure? Sound?

 

Pipes are the same length just about maybe couple inches.... but whatever it is, the front cyl compression is lower so i dunno.Its been sitting ALOT ,hence only 16k on it.
Yea Rawhide,It might just need taken out and rode hard for a couple miles and thats what i plan on doing ..LOL

 

Check your compression with the motor hot. Should be something around 125 and no more difference then a couple of psi between cylinders. f you want the real skinny do a leak down test.

 

Yea, going to dump some oil in eacj cyl. and see what happens tomorrow...Today when i done it i let it set for about 3-4 minutes to see if the pressure would bleed off....didnt seem to.Ill check tomorrow when the engine is hot. It fires up IMMEDIATLY,no smoke, no noise of any that i can hear....but something definatly is going on...