Hi, I bought my 954 about 3 months ago. Everything has been fine with it but this morning I heard a new noise. Under acceleration it sounds like almost a harley or like a subaru with an exhaust.. Like a deep toned thump while accelerating. I also noticed it's pretty gutless now.. Not as torquey and just to see how gutless I pinned it on the freeway and doubt it would go over 120. I know for sure it has a bad fuel pressure regulator and am waiting for that to come through the mail. But i don't think a bad regulator would all of a sudden do this. I think the regulator has been bad since I purchased the bike, I just noticed the poor fuel mileage and decided to check the vacuum line and it was full of gas. I read in another thread of a similar issue saying the spark plug was loose? I was curious if they start unscrewing themselves or if the boot comes off? Thanks for any help

 

Check this out. 100% sure this is your problem. Easy fix.
https://cbrforum.com/forum/how-103/h...ulator-129704/

 

It's the fpr. Ur dropping a cylinder or two bc it's flooding the cylinders with fuel. If I were you, I would park the bike until the fpr is replaced. I would also check the plugs to make sure you haven't fouled them out and change the oil. The spark plug boots do not screw on, they just snap over the plug. I highly doubt it's worked it's way loose.

 

If you try to run the crap out of something thats not running right, you will certainly do some damage eventually.

 

Ok, I will park it until the regulator gets here and Ill change the plugs too because it's due for it anyways.. On this particular tank I accidentally put 87 in it and last night I put 91 in it and the noise/running bad is gone.. Not sure if that was it but i'll wait till my parts come in just to be safe

 

87 is fine. I' gone 5000 miles with just 87.