The Honda PCX / Forza / ADV150 / SH Forums

Got to work this morning and the noise was worrisome. Knocking, rattling, like something has come loose. Didn't have the noise when I left for work. About a 10 min drive. Had a new ncy kit in there for a couple months. Haven't had it open in about a month when I changed the gasket. Been running fine until this morning. Will it get me home to work on it? Any ideas. Will open it up tonight either here at work or at home.

I wonder if one of the rollers came loose, though I don't know how it would. The rollers are tucked in the variator fairly secure, two at a time.
I do know that if the nut that holds the assembly came off it would stop running all together. Dave and I had that problem once, and the bike just stopped going forward.
Is the knocking only when you start off, like the clutch slipping? Glazed clutch pad?
How old is the belt? If it is old enough it could start shredding. I'm running out of ideas.

If it is only a 10 minute ride, how much is at high speed?

I don't know if it will still go. Knocking is when idling and and at 5-10mph speed, although thats the only time I noticed it. I didn't hear it till I pulled in to work, stopped, shut it off, and restarted. Hasn't run since. I'm thinking belt, or one of the big nuts is loose. Maybe the clutch. Won't know until I open it up. Maybe a roller but I don't know how that could happen either. Acceleration was good and consistent Maybe 5 min at 40 to 50mph. Belt has maybe 500-750 miles on it. Replaced when I got the ncy kit. Will update what I find.

It's not the variator or clutch or pulley. Ran it with everything off. No variator, belt, clutch, etc. Still had the noise. Something in the engine. When I Rev it seems to go away or less noticeable. Could this have been caused by the new exhaust I put on 10 days ago? See the vids. One of the sound with engine off and one with it on.
https://youtu.be/WtL2kj23LDA
https://youtu.be/Hr_LYQNkfLI

drove the 10 min home. seemed normal other than the noise. At speeds above 15-20mph, the noise is inaudible but I heard it in the exhaust this time and also had some backfires. Backfires to be more common since the new exhaust. I'll put the OE exhaust back on later and change the oil. Figure if there is engine issues it will show in the oil. If that doesn't fix it I'll send it to my local honda dealer. It's over my skill level I'm afraid.

viewtopic.php?f=9&t=8897

Link about my 10 day old exhaust.

Just added about 4oz of oil. No idea. Checked a couple months ago. Just hope I didn't go too long like that. No sign of leaks or burning oil. Gonna start fresh tomorrow.

Backfires are usually caused by an air leak or exhaust valve hanging open too long.

Seems to be above my skill level as well. You tightened the flange bolts and gasket enough on the new exhaust right? Is it one of those kind of exhausts that has an inner and outer pipe? Sometimes welds break on exhaust systems internally and they rattle. My old Honda Rebel 250 eventually had rattling exhaust pipes.

What else have you modified on the bike?

you you wrote:What else have you modified on the bike?

Variator and clutch, accessory lights, and the exhaust. That's all.

I've determined from other scooter forums (not hondapcx) and from YouTube vids describing a very similar sound in scooters that this may be the crankcase bearing. Not easy to get to.

neb4152 wrote:

you you wrote:What else have you modified on the bike?

Variator and clutch, accessory lights, and the exhaust. That's all.

I've determined from other scooter forums (not hondapcx) and from YouTube vids describing a very similar sound in scooters that this may be the crankcase bearing. Not easy to get to.

I think I'd definitely pop the original exhaust on and see what happens..

+1
If you still get the rattling after you replace the exhaust with the original one make sure your valves are adjusted correctly too.

Was the engine 4 oz low on oil? That isn't much but on a little engine that does not use much it is worth the effort to make sure it isn't leaking.

Mel46 wrote:+1
If you still get the rattling after you replace the exhaust with the original one make sure your valves are adjusted correctly too.

Was the engine 4 oz low on oil? That isn't much but on a little engine that does not use much it is worth the effort to make sure it isn't leaking.

4oz is all i had. stick was bone dry until then. may have been able to add more. i checked the oil and the valves a couple months ago. the more i think about it the more i worry i went without oil in the right places. working on getting it transported. It will still run and go but Im not taking any chances.

Was the level shown on the dip stick correct after you added the 4 oz ?