16 replies to this topic

[pusb]

My engine seems to have developed a hissing sound under acceleration.

Could this be an air leak?

Ive attached a picture of a hose that goes to the carb from something behind the engine (forgive my lack of technical terms). This hose looks in a very bad state, so could that cause the noise?

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[Yoda]

Get another piece of hose, stuff one end in your ear, wave the other end around the engine bay until you hear the hissing sound. Home in on it and take a good look around for a split, hole, loose pipe etc. If this is not successful, come back for the next answer.

 

I would replace that hose anyway, and any others that look a bit perished too .

 

Check round the engine bay for Snakes too. They hiss.

Edited by Yoda, 19 May 2014 - 12:09 PM.

[Dan]

Yes, and yes. Could be. That hose doesn't look that bad but it is the wrong part and likely to leak because it'll be too big at the carb end.

[Gremlin]

Yes, it could be the noise, but I would expect to hear it more when there is a higher vacuum - idle or overun - yes change it, and the thing behind the engine is the crankcase breather can that attempts at condensing any oil vapour

[Dan]

The emissions port is where it is on the carb body for a reason, the engine only safely burns off vapours at large throttle openings. There should be little or no depression in the emissions hose at idle.

[Yoda]

Its a bit difficult to see in the image, but does anyone else think that the filter box may be loose? could just be this and you can hear induction roar from the carb elbow. But change that pipe anyway.

[megamini_jb]

Mine has starting sounding like as if I've got a dump valve fitted? Would this be same thing?

Haven't lost any performance, but I'm sure it never used to so don't know why...

Edited by megamini_jb, 19 May 2014 - 12:27 PM.

[Yoda]

hmmm. sounds like it could be your warp drive overbalance negative gravity valve is leaking. or it could be another split pipe blowing raspberries.

Edited by Yoda, 19 May 2014 - 12:31 PM.

[pusb]

Interesting yoga that you mention the air filter box. I had that off at the weekend and it only seemed to start making the noise after that.

[Yoda]

I do not do Yoga, but you can call me Yoda if you like. 

 

So, when something happens to go wrong. The first place to look is the last place you touched is it not eh? Maybe a lesson is learned here.

 

Silly i may seem but right i am often. Go check and let me know if right i am.

[coopdog]

hahaha yoda is on one today!!!

but yeah its the air box making the noise, its just induction noise

[Yoda]

I might be on one now, but later i will be on more than one.

 

Anyone up for a beer?

 

Too hot it is to work.

[cal844]

I might be on one now, but later i will be on more than one.
 
Anyone up for a beer?
 
Too hot it is to work.

make mine a magners!

[megamini_jb]

hahaha yoda is on one today!!!
but yeah its the air box making the noise, its just induction noise

Oh yeah, forgot I had a K & N filter swear it never used to be as loud though lol

[coopdog]

 

hahaha yoda is on one today!!!
but yeah its the air box making the noise, its just induction noise

Oh yeah, forgot I had a K & N filter swear it never used to be as loud though lol

 

just enjoy the noise :L