Pinging or rattling in 5th gear

[BigRed]

Today, while traveling on a highway, I noticed a strange noise. Seemed like almost every time when going up a hill, if I tried to open up the throttle and speed up (was going 70 mph) I would hear a noise that sounded like a loud rattle. If I eased off the throttle the noise would immediately go away. Was that my motor pinging? If so, what could be causing it? I run my bike on 93 octane gas.

[dshelly]

Bad tank of gas.

[BigRed]

Originally Posted by dshelly

Bad tank of gas.

Filled up @ Gulf this morning and rode 150 miles. My next fill-up will be @ Shell.

[HwyRider]

I would guess something is loose on the bike. You've ridden that bike a lot without any sounds coming from it. Maybe a bolt is working it's way loose somewhere on an exhaust cover. Have you added anything to the bike recently?

[HwyRider]

This will fix the problem as well as the seat issue.

http://boston.craigslist.org/nwb/mcd/5044946284.html

[BigRed]

Originally Posted by HwyRider

This will fix the problem as well as the seat issue.

http://boston.craigslist.org/nwb/mcd/5044946284.html

Are you offering to buy me a new bike?

[cnc]

Try down shifting into 4th and accelerate to see if it still does it.

[BigRed]

Originally Posted by cnc

Try down shifting into 4th and accelerate to see if it still does it.

@ 70 mph?

[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.

[MAS Tequila]

When is the last time you ran some SeaFoam through it?

It sounds like detonation, but there are several causes.

Try running several ounces of SeaFoam through the fuel tank, and a couple ounces of MMO wouldn't hurt either.

If you're running anything other than regular gas, you most likely have deposits that need to be cleaned out.

MT

[BigRed]

Originally Posted by MAS Tequila

When is the last time you ran some SeaFoam through it?

It sounds like detonation, but there are several causes.

Try running several ounces of SeaFoam through the fuel tank, and a couple ounces of MMO wouldn't hurt either.

If you're running anything other than regular gas, you most likely have deposits that need to be cleaned out.

MT

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

[dshelly]

Lately I started running 87 or 89 octane fuel with this starbrite fuel additive. Bike hasn't pinged one bit. Actually runs better than on 93. Plus my mileage went up a little. This it great stuff. Seafom and MMO never impressed me, they seem a little harsh. This stuff will clean out you fuel system as you ride. I use it every tank..

http://www.starbrite.com/item/star-t...ategory_id=587

[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.

[recumbentbob]

Originally Posted by BigRed

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

Yes and rural king.

[CBO Vaquero]

If it is pinging don't let it continue or you'll end up like my old Mean Streak. The previous owner added really loud pipes and a custom air cleaner without adding a "tuner". When I put the stock stuff back on and you could finally hear the motor it was too late, rattled and knocked terrible. He had been riding it with it pinging but couldn't hear it and knocked the pistons out of it. I had to have it bored oversize to save it.