98 speedster engine vibration

[cenzo4dub]

this is getting a lil frustrating. one engine runs mint one engine runs rough at idle and low rpms. runs great at top speeds,although it only shows 5600 rpm at WOT-but ii think its not a correct reading as im getting 55mph on gauge with 4 people on boat. engine hard to start and vibrates alot when running and even harder to start after its hot. went thru the carbs twice and everything is clean and flowing good have put in 2 sets of plugs, cleaned the rave valves and did a compression check (150) both cylinders. replaced both inline fuel filters. also im getting a weird cough like sound every 3 or 4 secs. this problem is getting annoying and ive noticed these threads die out pretty quickly and alot of problems dont get resolved. but again any input would be greatly appreciated. im thinking maybe its an oil injection issue? also i read somewhere to check the crankcase oil and add if nessacary. how do you know how much to put in if you need it bc you cant really see in it.

 

[Dr Honda]

The only threads that die out are the ones where the owner gives up.

OK... it can be a few things.

1) Carbs. (this is for the hard starting) You said you went though them... but did you

A) verify the jetting?
B) Verify the pop-of pressure?
C) Did you do your rebuild with OEM parts? (aftermarket parts all suck)


2) Did you verify a spark? The wire at the boot is known to burn. When we see issues like this, We recommend cutting the wire back about 1/4", and put the boot back on.

3) On the "Coughing" comment... did you check the charging on that side? When the rectifier goes bad... the CDI will do strange things.