BannedCR500Riders.com

I just recently put my topend together and noticed that when wide open it seems to make some clattery noise, first i thought it was my worn out front sprocket, changed that and it didn't go away. Seems like it only does it in 4th or 5th, so am hoping its not something in the engine but i,m not sure. Took the rollers off and lubed them hoping it was those, noise is still there. It only happens when wide open or close to it, worried that its just gonna grenade sometime. Any assumption on things i should check or fix before something goes wrong.

I had porting done by gss and was wondering if my jetting should change. Right now its at #50 pilot, #170 main, its a Keihin PJ. Close to sea level.

I think your main is way off. i just put my 01 back together with new stock bore with bridgeless gss porting. rad valve, pro circuit pipe, pj carb, 93 250 ign. ran it all weekend at Hollster Hills in Calif, 660 ft elevtion. got it sorted out, ended up with 58 pilot, dgn needle which is jut a hair lean on bottom clip, 185 main. 190 main neutered power. perfect running motor with sonoco 110 mixed 50/50 with 91 and 927 at 32-1.

I'll ask the obvious. How does the plug look after doing a 4th or 5th wide open and hearing this noise??? Could give you a lot of information on whether or not you are too lean and causing ping.

Your wristpin is coming loose, probably lost a clip.


Just kidding. But seriously, did you check all tolerances including the crank before you put it back together?
Under power, you're more likely to hear piston slap.
Did you put a NEW top end in it?

might be the cam chain tensioner

Pinging.

variable port timing aint adjusted right ?

britincali wrote:Pinging.

That's more than likely what it is.

X3 on the pinging...

Thanks everyone, I think i'll change the jetting, if that doesn't help anything I move on to octane booster. I have no idea where to get anything besides 93 octane. I will warm the bike up change the plug out and try to get a benchmark plug reading before i start messing around with the jetting.

Do you think i need a new powerband.

Jet isnt going to solve pinging at 3/4 throttle

Change the needle.

my short rod wouldn't stop pinging the the dgn so I switched to dgj

kptkyle wrote:Thanks everyone, I think i'll change the jetting, if that doesn't help anything I move on to octane booster. I have no idea where to get anything besides 93 octane. I will warm the bike up change the plug out and try to get a benchmark plug reading before i start messing around with the jetting.

Do you think i need a new powerband.

AvGas, 100+ octane

There's a really good jetting thread on here, maybe check it out.

kptkyle wrote:Thanks everyone, I think i'll change the jetting, if that doesn't help anything I move on to octane booster. I have no idea where to get anything besides 93 octane. I will warm the bike up change the plug out and try to get a benchmark plug reading before i start messing around with the jetting.

Do you think i need a new powerband.

I had to have the squish band on the head modified to continue running pump gas. My jetting seemed right. it would just heat up and start detonating under load. Sounded like bb's rattling around in the crank.

Problem fixed, I put in a 58, and 185. I asked for the needle one of you ran but my shop here doesn't carry needles. I lost a little top-end but for the trade-off of for a healthy running bike is no problem. I'll definitely check out the jetting section. Thanks again.

kptkyle wrote:Problem fixed.