10W-30 oil causing the problem...

[Over_Easy]

Friend has a SV-650 and changed to a Castrol 10W-30 from 10W-40...don't know the specific make. He had always used but since he started using the 30 it isn't running well...sputters, backfires, sluggish, etc. I told him to check his owner's manual to make sure it meets all the oil standards for his engine...he believes it does.

If it does could the fact this is the first time using 10W-30 oil be the problem?

Keep in mind this is a SV-650 motor.

[SHADiGUY1]

did he fill it correctly i have heard of them problems with over filling.

[roadthing]

did he fill it correctly i have heard of them problems with over filling.

+1 on that suggestion.

I'd go for that first, especially if it's sputtering, back firing, etc. As it's a wet sump motor, overfilling will immediately cause breathing problems. Breathing problems wreak havoc on any engine, and can be a bear to diagnose.

[heykenny]

+1 on the above... it's not the fact that it's 10-30.. it's that he checked the level while on the sidestand or some other goof

[Over_Easy]

Thanks fellas. I'll check with him on how much he used and get a true level reading.