02 380SX Engine knock

[gabr999]

I've have an 02 380SX. The problem is that the engine has a knock around 1/8 throttle. The knock sounds like a hollow matalic ping or knock. When getting on the throttle I hear one knock, when I chop the throttle I hear one knocking sound. Around 1/8 throttle the motor will knock continually at that throttle setting. The dealer rode it and said he thought it was jetting.? As far as things I have tried; pump gas w/93 octane, race gas, and a mix of both. Premix is Yamaha 2R 32to1 and 40to1. Jetting; started with stock with richer mains and pilots, now I've switched to R1467N needle middle pos., 170-172 main, 48-50-52 pilot with no success. The bike runs good except for the knock. I'm running stock pipe and silencer. I've also tried changing the timing but still had the problem. I'm thinking it could possibly the power valve or the govener for the power valve? Or are 380's noisy motors (it shouldn't sound like this). Any help would be greatly appreciated.

 

[jeb]

It's hard to say without hearing it, dude. My 380 was a noisy bugger but I don't remember any knocking. It's been 4 years, though. Has it always made the noise?

 

[380EXCman]

I have an 02 380SX and I had a 99 380E. This may sound a little weird but both bikes had some knocking when I would chop the throttle. Other than that all the other symptoms the bike had were that it was rich. I actually ended up leaning out my jetting and the knock went away. I still prefer my bikes to be on the rich side. So by most peoples standards it is probably still rich. They are fairly noisy motors and having a skid plate would amplify those sounds. I have also heard of people using different tappered needles and fixing the problem. I guess I wasnt much help. I would just tinker with the jetting a little. Try leaning it just a little and see what happens. If that dont work try going richer.....

 

[gabr999]

380EXCman, did you lean out your pilot jet? What jetting are you running? I'll try leaning out the mid range, I've been going richer thinking it was lean. I'll let you know how it works.

 

[crazycarl]

my 02 380 sx had same pinging at 1/8 trottle.it also would kick/ backfire sometimes while kicking over.i tried all different jet/needles.the best set-up for chicago,il is 45P NOZG-2 170 MAIN and timing set right in the middle of the 2 marks(was set on left one).this setting runs/starts perfect no pinging
the timing advance made big improvement and removed all pinging !!

 

[380EXCman]

Yep I leaned out the pilot on step.. Im running 170 42 NOZH #2. For elevations 2500' to 8000'.

 

[Idaho Charley]

My 98 380 exc has a number of sounds. One is the chain hitting the mud deflector. One is the power valve mechanism under partial throttle and when I chop the throttle. I worried about the power valve noise initially and had the dealer check it out and he said it was fine. I can shift the rpm point where the power valve noise occurs when I chop the throttle by changing the PV preload. After 5 years of riding it (about 4000 miles) and experiencing no problems associated with either noise, I just turn a deaf ear to it.

BTW - Every once in a while a shrill sound will be emitted from the rider. Usually associated with pucker in the seat material and smile on the lips. LOL Life is great!! Later.......