LCGB Forums

At last i have the opportunity to have a proper play with my TS1,it went 'BANG' back in 2005 (panel grill clip went down the carb ),eventually had the cash for a piston and a re-plate in 2010,new bearings/crank/seals/head in 2014,and it clatters like the piston is touching the head (but it isnt),stripped it again,cant see anything amiss,put it back together again,still clattering!,cant be piston slap (can it???),not even 700 miles on the clock,standard porting,run on fully synthetic at 4%,34mm Amal (the VHSA 30 has given me nothing but grief so its relegated to my other project),JL 'CURLY' pipe,and im losing the will to carry on ,is this going to end up as an expensive paper weight?

Does the clatter go when it's warmed up?

What is the piston to bore clearance?

Have you checked the skirt isn't touching the casing a BDC?

'Clatters' when hot and cold,piston definately not touching anything at top and bottom...........................BUT........................I HAVE JUST DISCOVERED SOMETHING AND ITS MY OWN BLOODY FAULT
Normally (if im doing a job for someone else),ill check everything that arrives for that particular scoot,just to make sure there wont be any problems,BUT..... just lately,when ive had time to do my own stuff,ive been very slack,and just trusted what ive sent for being what it should be!,Obviously,when i eventually got the TS1 back after a 5 year break,i assembled it without checking everything,and just assumed it would be ready to go......................WRONG....................I have a grade 'A' barrel,with a grade 'B' piston,possibly the clatter being an undersize piston???????...DOH!

Or possibly not!!

Did you check the clearance between the crankcase and the webbs on both sides & top and bottom while rotating the crank ?

Only rattles at low revs ? or it gets continually worse as the revs rise ?

Flywheel touching somewhere on the mag side on either the cowling, stator, mag housing itself or the nuts and bolts that hold the mag and stator in place these often gives a rattling rubbing scraping sound but might be worth looking to see if there's any witness marks.
Flat slide carbs often make a slight rattle clicking noise at tick over.

rossclark wrote:
What is the piston to bore clearance?

I can get a 0.006'' feeler between the piston and bore!!,seems like a lot of wear for the massive 650 miles its covered

Captain Pugwash wrote:Did you check the clearance between the crankcase and the webbs on both sides & top and bottom while rotating the crank ?

Only rattles at low revs ? or it gets continually worse as the revs rise ?

Flywheel touching somewhere on the mag side on either the cowling, stator, mag housing itself or the nuts and bolts that hold the mag and stator in place these often gives a rattling rubbing scraping sound but might be worth looking to see if there's any witness marks.
Flat slide carbs often make a slight rattle clicking noise at tick over.

Everything with the top end off turns smoothly,with no 'flat' spots,this thing clatters when cold and hot,i reckon its just well worn for some reason or another,so much for 'nicasil' being hard wearing!

If it's 6 thou in Line with but at 90 degrees to the gudgeon pin then I would say it's worn.

Captain Pugwash wrote:If it 6 thou in Line with but at 90 degrees to the gudgeon pin then I would say it's worn.

650 miles though!!,something went wrong big time!!

kevspeed wrote:

Captain Pugwash wrote:If it 6 thou in Line with but at 90 degrees to the gudgeon pin then I would say it's worn.

650 miles though!!,something went wrong big time!!

I've done over 20,000 on the same bore and the barrels still good to use, maybe your TS barrel was oversized from new.

The plan now is to get it sent off and looked at,then brace myself for the quotation to get it put right!
If its too much for me to consider being worthwhile,ill have an 'attractive paper weight' to look at!

kevspeed wrote:'Clatters' when hot and cold,piston definately not touching anything at top and bottom...........................BUT........................I HAVE JUST DISCOVERED SOMETHING AND ITS MY OWN BLOODY FAULT
Normally (if im doing a job for someone else),ill check everything that arrives for that particular scoot,just to make sure there wont be any problems,BUT..... just lately,when ive had time to do my own stuff,ive been very slack,and just trusted what ive sent for being what it should be!,Obviously,when i eventually got the TS1 back after a 5 year break,i assembled it without checking everything,and just assumed it would be ready to go......................WRONG....................I have a grade 'A' barrel,with a grade 'B' piston,possibly the clatter being an undersize piston???????...DOH!

Isn't a B grade piston bigger than an A grade?

Now i would have thought that!,so something has gone wrong somewhere!!
I gave a quick call to 'Rayspeed' and was told that the difference in grades of piston was around half a thou,so.................

grade 'B' piston is slightly bigger than the grade 'A' one, but did you send the piston with the barrel to get re-plated?
what's your timing set @? 19 to 17degs?

Without reading the above (sorry if said all ready)

Piston skirt hitting the deck?..... Skim with wet&dry over some glass...