Suzuki 2 Strokes

So I am noticing a few things with my T500.
Engine completely rebuilt including crank and wiseco pistons. I have about 70 miles on the bike since complete rebuild.
Carbs are stock, UNI pods with higgspeed chambers.

Noticing two things. wondering if anyone can comment on them:

1) since the beginning, I have noticed a strange noise on the bike. It sounds like a metallic rattling noise. It almost sounds like keys being jiggled together. I seem to notice it mostly when idling along at a low RPM down the road, but it can be present other times. I initially chalked it up to my keys rattling against cylinder head on the left, but it turns out that is actually not the noise. Seems like its coming from engine, but tough to tell. Thoughts?

2) second issue just started last week. I took the bike out for a drive. Warmed it up for a couple minutes. Took off down the road. Seems to drive just fine until I got about 1/4 - 1/2 mile away and it started missing on what seems like the left cylinder. I would hear a loud pop, then lose some power, then a loud pop, and lose some power and it kept doing this for about 1/4 mile. I pulled over to the side of the road. I assumed I was possibly low on gas (which I was) and I turned reserve on and drove home. It drove home fine the entire way home. No issues. seems like problem solved? except it did the same thing today. Warmed up bike. Initially runs great, then about 1/2 mile down the road it starts popping real loud and misfiring. I turn around and start to drive home and it stops after another 1/2 mile and didn't do it. I put on another 10 miles with no issues. Any ideas what is going on?

Does the noise go away if you pull the clutch? I have noticed the transmission can rattle a bit in neutral on mine pull the clutch and it disappears.

I will check what you suggest.

Anyone have any thoughts on the popping and missing described above?

If the key jangling noise is not the clutch, I would suspect that it's pinging.

Check ignition timing and jetting. It may need to be slightly richer on the pilot jet.

Popping sounds like the fire is going out and then coming back and igniting the unburned fuel. My first thought is fuel tank breather or dirt in the fuel system but it could also be a short or break somewhere in the ignition system. I would start by draining the tank and carbs and check teh fuel tap filters and float bowls.

What sort of ignition system do you have and are teh coils and switches and leads all new or "pre-loved"?

tz375 wrote:If the key jangling noise is not the clutch, I would suspect that it's pinging.

Check ignition timing and jetting. It may need to be slightly richer on the pilot jet.

Popping sounds like the fire is going out and then coming back and igniting the unburned fuel. My first thought is fuel tank breather or dirt in the fuel system but it could also be a short or break somewhere in the ignition system. I would start by draining the tank and carbs and check teh fuel tap filters and float bowls.

What sort of ignition system do you have and are teh coils and switches and leads all new or "pre-loved"?

Coils, electronic ignition, regulator and rectifier are all brand new from power dynamo. plugs are brand new. there is nearly a zero chance of there being sludge in the gas. The tank is fresh metal with caswell sealer and ethanol free premium gas. I have clear external fuel filters that both look perfect and the carbs are completely rebuilt with all new needle and seals. I Have only gone thru about three tanks in the few months that I have had this bike together. the strange thing is why would it do this for only a couple miles of driving, then stop? And why would it take 1/2 mile before it starts doing it?

I can't remember if the PD system is fixed timing or if it has a timing curve. If it has a curve, it typically would be full advance at low revs and that may be too much advance. If it's fixed, you could try retarding it slightly from where it's set and see if that makes the noise disappear.

The bike is certainly extremely clean and nicely done, but it's still possible that there's a flake of dirt or water globule in the fuel system partially blocking a jet. Drasin teh float bowls and see if they are spotless or if there's some dirt or water in there.

retarded the timing a bit on my powerdynamo. Didn't really change the clinking noise at all.

As for the popping and misfiring- I Checked over the carbs again. No debris in the jets. Bike still does a bunch of loud popping and misfiring on the left cylinder between mile 1/2 and mile 1 after you first riding it from cold start. Doesn't seem to matter if I let it warm up several minutes before riding or not. It Doesn't misfire or pop immediately, and it completely stops doing it after about a mile of riding. Still baffled by this problem. it never did this the first month I had the bike running. Just started doing it last week and now it does it every time I take it out. Would love to hear someone else's thoughts on this.

Stop and pull the plugs when it does it what do you see. Colour, wet, oily?

I figured I would post a follow up to my issues. They seem to be mostly resolved.

Regarding the clinging and metallic jiggling noise, that seemed to be fixed when I advanced the power dynamo electronic ignition slightly. Thanks Teazer for that suggestion.

Regarding the second issues of the popping on one cylinder- that took a bit more work to sort out. I will say it is somewhat embarrassing because the solution was very simple, in the end.
Basically I decided to troubleshoot on saturday. i checked compression- good. I checked timing- good. I checked all the carb passages again (for the third time)- good. I torqued down the cylinder head again- all good. I checked the oil pump- good. Basically I was ready to go insane sorting out this stupid popping that only occurred within first mile of driving.

Long story short- I went to the local ducati dealer for the open house and drove the T500. I test drove an MV Agusta Brutale and I loved it! I totally need one now. Driving home after test drive and the T500 dropped a cylinder completely, and I Barely made it home.

At this point, I had literally checked everything mentioned above within the past three hours. I figured what the heck, I will check the coils. Kicked her over on the left cylinder with plug out and I get a nice fat spark. Kicked her over on the right cylinder and nothing. The plugs were basically brand new (40 miles on them) and they looked fine. Either way, I decided to replace the plugs because they were cheap enough, and voila! The bike now drives perfectly. No more popping for the first mile.

Seems strange to me but I am not complaining. I guess I figured a fouled plug would have acted differently. I basically drove that bike about 10 times with the issues of it popping for the first mile, before finally the plug decided to crap out completely

Anyways, live and learn. This has been humbling to say the least. The bike rides great again. (After the test drive, I was so frustrated with this T500 that I was convinced I was going to sell it and buy that MV Agusta, but now I guess I will keep the T500 a little longer).