Engine knock and bogging down when throttled...

[Nefarioc]

So my 05 is bogging down and turning off on me and the knock is pretty loud. I'm worried because I'd hate to take it in and have it misdiagnosed. I changed the oil on it recently and it worked fine...then drove it a lil while only to have it bog out on me again. I thought it might have been a firing problem as my bike has 17,000 miles on it and needed new sparkplugs. So I changed those out last night and it ran flawlessly. Well, I got on it the morning and once again bogged out on me multiple times and died.

I've done all that I can think of without pulling the motor...I've called some service shops around here and they say if it is a piston or valve that I'm just about better off buying a new motor. Is that right?

(the check engine comes on very briefly during the bog)

Any help about options would be appreciated.

 

[SHADiGUY1]

do a compression test on all the cylinders

 

[Supergank1]

you might try cleaning the fuel injectors before you take it anywhere??

 

[Nefarioc]

do a compression test on all the cylinders

How would I do that? Do I take it in and ask the shop to do it? I've done almost all the work on my bike myself.

 

[SHADiGUY1]

go and buy a compression gauge they sell them at most car part stores maybe even a sponsor would have one they could sell you then ou pull the plugs one at a time put the guage where the spark plug should be and fire the motor it will tell you a compression reading. do this in all 4 cylinders.

 

[Nefarioc]

go and buy a compression gauge they sell them at most car part stores maybe even a sponsor would have one they could sell you then ou pull the plugs one at a time put the guage where the spark plug should be and fire the motor it will tell you a compression reading. do this in all 4 cylinders.

Ok...and I assume that if one of the cylinders has a low reading then it's busted? What sort of diagnosis will the compression test give?

 

[heykenny]

my advice is to take it to a mechanic.... knocking loudly.. that's not good. I don't mean to sound rude, but if you don't even know about compression testing,you certainly don't have the skills to be inside a busa engine... And quit running it.. if it really is eating parts,you'll just make it worse,and more expensive.

 

[300Busa]

could be a problem with fuel getting to the motor. Maybe dirty injectors, pinched fuel line, dirty filter, bad fuel pump....just hoping that it isn't anything major for you.

 

[MC MUSTANG]

You mentioned that it sounded fine briefly afetr changing the spark plugs? Check the coils and see if one is bad, you may only be firing three cylinders.

The way to check is to remove the spark plugs and reconnect the coils to see if all of them spark... if they don't then chek that spark plug on another coil... you might need a new one...

A relatively easy check and you don't need to run the motor to do it.

 

[Nefarioc]

I appreciate all the advice guys.  I just recently painted my gas tank so I'm hoping it is something to do with the fuel system.  Perhaps something went wrong when I reinstalled the fuel pump...I hope it's that minor.

However, the bike runs perfectly fine when in Neutral...the engine only bogs when it's in gear.

 

[Crazyhorses]

Need to clean the whole fuel system out.

 

[GoldenChild]

check the vacuum line that goes to the little sensor on back of airbox and be sure it's connected to the nipple.