Pinging or rattling in 5th gear

[cnc]

Originally Posted by BigRed

@ 70 mph?

Maybe not down shift right @ 70, but you can accelerate past 70 in 4th to see if you get the same noise.

[cnc]

Originally Posted by HwyRider

Did you check the light visors to see if they could be causing the noise?

That's not so far off. I was once getting a strange rattle at a certain speed and it would go away as soon as I went a bit slower. Drove me crazy, even stopped the bike and looked it over completely. Finally I discovered the cause, the snaps on my helmet visor were rattling with the wind buffeting the visor as soon as I was moving fast enough. It really sounded like it was coming from somewhere on the bike.

[Teachme]

Love seafoam i put some in about every 4th or 5th tank of gas. I run it in everything i have that takes gas the scoot ,cars, lawn mowers and all.

[HwyRider]

If it's only happening at 70 mph and in 5th gear I doubt it would be fuel related.

[ctrider]

I've used both seafoam and star tron. I felt my bike runs better on sea foam but I know lot's of HD'ers that swear by star tron. I also don't mind paying more for 93. I usually run seafoam every 2-3 tanks.

I might go along with the headlight visor. You said it felt loose to you a few weeks ago. You can also try getting it up to 70 again in 5th then let off the throttle let it come down to 60 then hit the throttle hard. If it happens right away I would go with fuel and should not be a rattle but a ping if it's the fuel. Suppose you could take off the visor also.

[dgconstable]

Mine always pings,, it's a Nomad it will ping.

What I do to avoid it most times is gear down when it starts. I'm getting better at predicting when it will happen so I avoid it most times now.

[ubernomad]

Originally Posted by BigRed

I've never run SeaFoam through it. Is this available at the local auto parts store?

Seafoam isn't going to solve anything. It *might* clean up a little bit of carbon deposits, and maybe clean the injectors, but if you are lugging the engine at low rpms under heavy load you might have engine knocking (aka pinging or detonation). It's a very unique sounding metallic "ping" sound similar to someone hitting your engine with a ball-peen hammer. Reduced engien load and/or higher rpms typically reduces the noise.

The only solution is to run higher octane fuel and don't lug the engine under load in higher gears. 5th gear can be tricky at highway speeds below 60mph because it acts like an OD gear.

[ubernomad]

Originally Posted by dgconstable

Mine always pings,, it's a Nomad it will ping.

What I do to avoid it most times is gear down when it starts. I'm getting better at predicting when it will happen so I avoid it most times now.

If it's truly "pinging" that's bad. Very bad. It kills pistons.



One solution no one has thought of is to run water/methanol injection. Yes, it requires a water tank somewhere on the bike but I've used it on cars and racing jet skiis with outstanding results. Kind of the poor-mans version of running high octane fuel when you increase timing or compression. Water/meth is atomized in the intake and rapidly cools the intake charge to fight detonation. On a motorcycle you don't need a big tank so you could retrofit a tank in one of the saddle bags.