Whistling noise at WOT

GoldenMotor.com

Rollingstones

New Member
Apr 3, 2014
37
2
0
Los Angeles
Hello everyone,

I have been trying out a few different spark plugs and when I switched plugs at one point today my engine/exhaust/clutch (not sure which to be honest) started making a very high pitched whistle like noise.

It does not come in an exact cadence or anything its almost at random.

I have noticed that I have some oil coming out where the exhaust connects to the engine. This is the second muffler that this happens with, I just can't seem to get a perfect seal from muffler to engine for longer then a few days for some reason :-||

Could this be pressure from a leak at the exhaust due to my expansion chamber or does anyone know something else that can be causing it?

Any and all help or pointers are appreciated...
 

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
24
38
Ridin' inSane Diego, CA.
I'm pretty sure it's just the wind whistling past your ears at high speed. Everything else should be inaudible at WOT with a 2-stroke engine screaming underneath you.

dnut
 

Rollingstones

New Member
Apr 3, 2014
37
2
0
Los Angeles
It doesn't happen when just peddling with the clutch engaged so I don't thinks that is the issue : /

I think that either its a exhaust leak, head leak or the piston hitting something... not sure what it could be hitting.
 

Rollingstones

New Member
Apr 3, 2014
37
2
0
Los Angeles
I just did a run around the parking lot a second ago to see if I can pinpoint the source and it sounds to be the clutch...

Also when I let go of the clutch lever and give it gas it wants to boggle out as if it was not catching right and therefore not making the engine revolve...
 

crassius

Well-Known Member
Sep 30, 2012
4,032
158
63
USA
a clutch can squeal a bit if it is slipping (often heard just a bit by guys who let it out at too low a speed)

any oil showing up needs to be fixed & can also be a source of noise - the muffler hanger at the bottom should help to keep the muffler sealed at the top, but the head gasket might also leak very near there - clean it well & spot where it starts to show up
 

Dave31

Active Member
Mar 1, 2008
11,199
47
38
Aztlán, Arizona
One time I had a stock air filter cover that whistled. Took me a long time to discover that is what it was.

After trimming it the whistle went away. Not saying that is your problem but maybe something to look into.
 

Attachments

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
If you're having problems keeping the exhaust flange/gasket tight you might want to check the gasket surface of the pipe. They are usually warped from the welding process where the pipe is welded to the flange.

To check it for flatness, remove the pipe, clean the gasket surface and 'paint' it with a magic marker or machinist dye. Now rub the flange against a sheet of sandpaper laying on a flat surface, glass works best, and after a couple of swipes you'll be able to see high and low places. Those inconsistancies need to be removed so the gasket surface is as flat as you can get it.

Torque the fasteners to about 60 inch pounds and see if that doesn't keep things sealed up for you. You'll also want to use a better grade of gasket material than comes with the kits. Any auto parts store can provide you with quality, automotive type gasket material.

It helps to have a bracket that holds the lower end of the pipe so vibrations are reduced and keeps some of the stress off the flange and fasteners. Good luck.

Tom
 

Rollingstones

New Member
Apr 3, 2014
37
2
0
Los Angeles
Thanks 2door, I actually read the thread you stated that in previously and am following the steps. issue seems to be the bolts loosening rather then a faulty seal. Thinking about just doing a **** coil fix.
 

stinky

New Member
May 21, 2011
84
0
0
The South
Yeah also make sure the clutch flower nut retaining screw is tightened in!! Just watched my youtube video and that was making a horrible squeal as it ate away at my clutch cover!
 

Rollingstones

New Member
Apr 3, 2014
37
2
0
Los Angeles
Just wanted to provide an update.

Took the dang thang apart and it was an air leak at the head. Since I had it all apart I skirted the piston and cleaned up the edges a bit. Painted the bottom black and repainted the top blue since oil had been going everywhere on it.

She is a looker. Speedometer, tach and lights arrive tomorrow. If I could figure out a chain that is not so loud and make my tank stop spilling gas she would be perfect :)