Re: Noise from the barrel area/ new build
Posted: Tue May 08, 2012 5:38 am
73 Spanish 200
Scooterotica
The UK's No1 Lambretta & Vespa Scooter Forum.
https://www.scooterotica.org/forum/
Noise from the barrel area/ new build
Page 2 of 2
Re: Noise from the barrel area/ new build
Posted: Tue May 08, 2012 10:00 pm
Hi, have just had exactly the same thing happen on my new build, 20 mins with the wet and dry on a flat surface with the piston sorted it..
Re: Noise from the barrel area/ new build
Posted: Tue May 08, 2012 11:34 pm
ive had the same too, i use 110 rods now so illuminates it
Re: Noise from the barrel area/ new build
Posted: Thu May 10, 2012 5:49 pm
Took 0.5mm off the skirt & the piston is clear.
Barrel/piston is now proved to be not the problem. Gear box/clutch has been checked for peace of mind really because the noise is certainly the top end. Just built it up & started it........same noise.
The only thing it can be is the crank or mag bearing but these are new. The noise has been audible since the first start up so the most likely answer now seems to be the big end was damaged right away with the piston skirt kissing the casing.
Any thoughts anybody ?
Barrel/piston is now proved to be not the problem. Gear box/clutch has been checked for peace of mind really because the noise is certainly the top end. Just built it up & started it........same noise.
The only thing it can be is the crank or mag bearing but these are new. The noise has been audible since the first start up so the most likely answer now seems to be the big end was damaged right away with the piston skirt kissing the casing.
Any thoughts anybody ?
Re: Noise from the barrel area/ new build
Posted: Fri May 11, 2012 10:25 pm
And there's no other marks or scratches on anything inside?
I have the same symptom(of course, not necessarily the same problem) on a 165 i just made. Fitted to the bike 2 days ago. My squish is a bit tight, but within range. I plan on just screaming the hell out it til it blows up. I'll let you know what it was when it fails
Just a thought.....you said the piston is 67mm? Did you open up the head gasket from 66mm? Maybe the piston is tapping the ridge of the gasket?
I have the same symptom(of course, not necessarily the same problem) on a 165 i just made. Fitted to the bike 2 days ago. My squish is a bit tight, but within range. I plan on just screaming the hell out it til it blows up. I'll let you know what it was when it fails
Just a thought.....you said the piston is 67mm? Did you open up the head gasket from 66mm? Maybe the piston is tapping the ridge of the gasket?
Re: Noise from the barrel area/ new build
Posted: Fri May 11, 2012 10:49 pm
8 thou clearance thats big big! why this large clearance?
one mans rattle can be another mans knock ,i see you are from carlisle is there no one (expert) you can take it to for a 'listen' and get a second opinion?
one mans rattle can be another mans knock ,i see you are from carlisle is there no one (expert) you can take it to for a 'listen' and get a second opinion?
Re: Noise from the barrel area/ new build
Posted: Sat May 12, 2012 1:08 am
8 thou? are you sure...thats going to rattle big time. If you are sure of the piston to bore clearance measurement, thats your rattle right there.
Most piston slap can be heard at tickover.....if it disappears with higher revs its generally ok....if it doesn't , fix it.
Most piston slap can be heard at tickover.....if it disappears with higher revs its generally ok....if it doesn't , fix it.
Re: Noise from the barrel area/ new build
Posted: Sat May 12, 2012 7:46 am
Right from the off I changed the barrel & piston to take it out the equation.
Going to double check squish,timing & the fuel.
Next step is crank out & another one tried.
Going to double check squish,timing & the fuel.
Next step is crank out & another one tried.
Re: Noise from the barrel area/ new build
Posted: Sat May 12, 2012 7:56 am
I think when you take the crank out you may find some shiney bits where the big end has been catching the crankcase. I had to take a fair bit off the crankcase to get enough clearance on my MECEUR 60mm crank.