Holed B44 piston (follow on from tale of woe)

KiwiB44 · Post by **KiwiB44** » Sat Mar 04, 2023 5:31 am

Well I need a new plus 020 piston and hone as bore looks ok.

Anyone recognise this “TNO” japanese piston and have experience if this sort of failure? Maybe why it happened?

Its holed, in the exhaust cut out, and cracked through the gudgeon right down to the skirt. Marked by black dot marker pen

No fragments on sump gauze.

Is it a cast or forged piston?

What compression ratio ? any ideas?

BSA_WM20 · Post by **BSA_WM20** » Sat Mar 04, 2023 6:46 am

kommando · Post by **kommando** » Sat Mar 04, 2023 9:53 am

TNO seem to be a Japanese auto parts distributor, so may not be the maker of the piston. Difficult to tell as only online presence is a facebook page.

https://www.facebook.com/permalink.php? ... wUshY&_rdr

Cast and normal compression, there is only one piston compression for B44's with a standard barrel its 9.4:1, removing or adding height to the barrel is how the factory changed the compression with the GP having an 11.4:1 compression from a short barrel.

Never seen a piston fail that way before, no 4 corner seizing, pin shows sizes of over heating but was that pre or post the crack appearing.

eebtr7 · Post by **eebtr7** » Sat Mar 04, 2023 2:33 pm

Tell ya what...a little super glue with a dab of duct tape...and keep it under 9,000RPM, should get you about 225 yards down the road.

This advice from the Official Warranty department is brought to you at no charge, and as always, parking is free.

Post by **minetymenace** » Sat Mar 04, 2023 5:39 pm

A lot of B25's about that ran cheap pistons only to suffer the same fate.... time to call EdV

matt49g · Post by **matt49g** » Sat Mar 04, 2023 6:43 pm

I absolutely agree with Minety above. You might have to go to a bigger oversize and rebore as J&E pistons are set up with tighter clearances. Ed will talk you through the whole works.

KiwiB44 · Post by **KiwiB44** » Sat Mar 04, 2023 8:38 pm

EandV sounds a great outfit BUT I am in NZ so shipping would be an issue

. I am visiting the UK soon though so might be able to pick up a piston then.

I had not thought of JE brand pistons for a B44, I have seen Gandini brand pistons for sale though via Feked etc.

kommando · Post by **kommando** » Sun Mar 05, 2023 12:09 pm

Mark Cook is based in Yorkshire and has a good range of pistons, GPM and Forged which may be JE like EdV's,

https://pesltd.uk/?catalogue=bsa-b44&di ... crankshaft

KiwiB44 · Post by **KiwiB44** » Sun Mar 05, 2023 8:48 pm

kommando wrote: ↑Sun Mar 05, 2023 12:09 pm Mark Cook is based in Yorkshire and has a good range of pistons, GPM and Forged which may be JE like EdV's,

https://pesltd.uk/?catalogue=bsa-b44&di ... crankshaft

Thanks kommando, and I notice PES do a 475cc kit also

but then I would probably need a new con rod and bottom end bearings etc

I have found possible evidence of a piston fragment very slightly damaging the bore, little more than a mark but it might just affect the top ring seal, so I may have to get a rebore and go to plus 040.

If I was to just be cheap and fit a new JE piston, anyone know the bore size size they need? Is it smaller or bigger than needed for a std piston? (to suit their forged pistons, which EandV are stating need 003 clearance). This bike just gets used for a monthly rally, occasional longer trip.

I can see I might need to call EandV…….and I might need to fund a local firm that can do a good reboring job, not so easy in NZ nowadays

Jeff K · Post by **Jeff K** » Sun Mar 05, 2023 10:21 pm

I have found that most automotive machine shops can do a good job on boring bike cylinder out. But they do not have a clue on the clearance for them. You have to be real clear on what clearance that you want and they can finish hone it to your size. Get the clearance from the piston supplier, ie EDV.
Jeff

KiwiB44 · Post by **KiwiB44** » Sun Mar 05, 2023 11:34 pm

Pics of bore defect and equivalent mark in piston in top ring area

Jeff K · Post by **Jeff K** » Mon Mar 06, 2023 1:15 am

That one picture seems to show a "ridge" at the top from the piston ring. That would be normal wear for a high milage motor. But it would also mean that it is time for a Bore/hone job.
Jeff

KiwiB44 · Post by **KiwiB44** » Mon Mar 06, 2023 7:09 am

Jeff K wrote: ↑Mon Mar 06, 2023 1:15 am That one picture seems to show a "ridge" at the top from the piston ring. That would be normal wear for a high milage motor. But it would also mean that it is time for a Bore/hone job.
Jeff

I shall clean the carbon off and do the “fingernail” test and report back, but I am fairly sure this piston has not lasted long before failing. There are the remains of honing marks over most of the bore, the piston has some scoring but I think that is either dirty oil, or lack of an air cleaner (from prior owners not me

)

kommando · Post by **kommando** » Mon Mar 06, 2023 10:44 am

A good borer would require the piston to be in his hand for measuring and info on the required clearance. A 3 thou clearance would be too tight for a normal piston, so a piston with a recommended 3 thou clearance would make for a quiet top end once you can get rid of the tappet rattle.

KiwiB44 · Post by **KiwiB44** » Mon Mar 06, 2023 11:59 am

kommando wrote: ↑Mon Mar 06, 2023 10:44 am A good borer would require the piston to be in his hand for measuring and info on the required clearance. A 3 thou clearance would be too tight for a normal piston, so a piston with a recommended 3 thou clearance would make for a quiet top end once you can get rid of the tappet rattle.

I don’t have the necessary measuring equipment eg internal mic, but I will ask around to see if someone I know has, using feeler gauges to measure the gap between piston and cylinder has provided “odd” results eg that the bore appears to be tapered, the clearance being 006 at the top, 004 in the middle and 002 at the bottom (same part of piston). I need to measure this properly though.

If the bore is tapered it means a rebore from 020 to 040 over anyway, so no option just to get a new 020 over piston and the barrel honed, and yes I would give a new 040 piston to the machinest. I would usually ask a machinest what oversize to move to, but in this case I am confident 040 will remove the slight gouge, I just hope it was rebored square and concentric last time.

I cleaned away the carbon above the rings, and the wear ridge at the top is negligible, so its not done much mileage.

kommando · Post by **kommando** » Mon Mar 06, 2023 1:56 pm

You can get coatings that increase the size of a piston if its a matter of a thou or two. For daily riding you can allow up to 5 or 6 thou wear over the initial 4 to 5 thou clearance.

Mark Cook · Post by **Mark Cook** » Fri Mar 10, 2023 9:59 am

Have it bored to see if it cleans, the honing can be done later when you have the piston.
If you just have it honed to clean it up, the piston will rattle like a cock in a shirt sleeve.
We have liners on the shelf for those that have just gone too far.

KiwiB44 · Post by **KiwiB44** » Sat Mar 11, 2023 7:08 am

Mark Cook wrote: ↑Fri Mar 10, 2023 9:59 am Have it bored to see if it cleans, the honing can be done later when you have the piston.
If you just have it honed to clean it up, the piston will rattle like a cock in a shirt sleeve.
We have liners on the shelf for those that have just gone too far.

Thanks Mark, don’t worry there is no way I would try to get the imperfections removed by honing. Using verniers the bore is 79.5mm +/- 001 but I will get it properly measured with a mic. I’m pretty confident it will in spec for a plus 020 piston eg bored to the std size and not significantly worn.

I will then try to find a firm that has experience in boring this type of barrel (to plus 040) and which I can trust, I doubt I will, they keep closing down as the owners retire or die off! in which case I will take the lower risk option of a hone (to restore hone marks only) and fit a new std compression plus 020 piston, and cross my fingers the imperfection in the bore does not cause any issues. If it does I will have wasted the cost of the new piston

It is tempting to look into a PES 475cc conversion, especially as I am in the uk for 7 weeks soon and could bring the barrel over, but this is a lightly used bike….

Mark Cook · Post by **Mark Cook** » Sat Mar 11, 2023 10:10 am

If you in the UK, we can turn it around in a couple of days for you.
You can purchase all the other bits you require too and save on import duty.

Mark

KiwiB44 · Post by **KiwiB44** » Sun Mar 12, 2023 9:51 pm

Mark Cook wrote: ↑Sat Mar 11, 2023 10:10 am If you in the UK, we can turn it around in a couple of days for you.
You can purchase all the other bits you require too and save on import duty.

Mark

Thanks Mark, its great to know I have that option.

I try to avoid import duty (GST, 15%) if I can! Also UK VAT, if I can. The NZ rules are privately importing a shipment up to a value of $1000 (including shipping cost) is not liable for GST.

HOWEVER the NZ tax authorities require overseas suppliers (PES?) to charge GST if they export over an annual value of $60k to NZ, that is poorly policed however as when the $60k rule was introduced it was mainly to target Amazon, Ebay, Aliexpress etc, nit specialist old bike part suppliers

KiwiB44 · Post by **KiwiB44** » Tue Aug 01, 2023 9:54 pm

I’ve finally got around to fitting the new PES piston, the barrel has been honed and the piston/barrel clearance is bit bigger than I hoped for but less than the previous piston so I will give it a go. Ring gaps are a bit too large as a consequence as well.

The new gudgeon pin is a tight fit in the conrod, it actually pushed the bronze bush out when I tried fitting it, I have dealt with the slightly loose bush by expanding it very slightly and pressing it back into place (using a long bolt, and being careful to line up the oil holes etc). I then used a small hone to clean up the bore of the bush but that of course did not remove much metal and did not result in the pin still fitting without a bit of force (but it does now fit without the bush moving in the conrod though).

SO I am wondering whether I should now get the bush reamed out to give a working clearance on the gudgeon pin?

I notice the new pin rotates easily in the piston, and there appears to be oil supply holes to the pin in the piston as well, so maybe the pin is not supposed to rotate in the con rod?

If the conrod pin SHOULD rotate in the conrod, what should the pin to bush clearance be? I guess less than 001”?

Mark Cook · Post by **Mark Cook** » Wed Aug 02, 2023 8:21 am

The pin must move freely in the rod,

If the bore is oversize and out of shape, don't expect wonderful results.

Mark

KiwiB44 · Post by **KiwiB44** » Wed Aug 02, 2023 10:20 am

Thanks Mark, I will get the bush reamed out.

I’m not expecting great results, basically I am hoping to get away with just replacing a cheapo piston that holed after a few thousand miles with a decent forged one. It’s a gamble, but I only expect to do 2000 road miles a year absolute max (to rallies) on this bike.

I guess I will know pretty quickly if I should have rebuilt the whole engine, new sleeve, new rod, crank bearings etc

KiwiB44 · Post by **KiwiB44** » Sat Aug 26, 2023 6:56 am

Piston is fitted and there are no abnormal noises that I can tell and no obvious signs of burning oil, I’ve got to decide how long (and how) I run it in for now. I did about 20 miles after this vid was taken using light throttle no lugging and maybe 3500 rpm max.

I weighed the new +020 PES piston and even though its forged it weighed exactly the same as the holed cast piston so vibes are unchanged.

Onto the clutch and gearbox (3 new gears to be fitted) now, annoyingly the friction plates and springs I bought whilst recently in the uk turned out to no use so its got the surflex plates back in it, which I thought were worn out but are thinner than oem even when new, so aren’t.
The surflex plates also appear to need more spring pressure to avoid slipping than the unknown brand that were in it, so the clutch is heavy and basically awful.

https://youtu.be/AIYTeFIlZfY?feature=shared

ghislain · Post by **ghislain** » Tue Aug 29, 2023 9:56 am

To have a light clutch, I use american Barnett bonded plates an a PES pressure plate ....no need to tight hardly springs , and never have to readjust clutch ...
They are now more than 30000 km old, and don't show any wear ...

KiwiB44 · Post by **KiwiB44** » Tue Aug 29, 2023 9:32 pm

ghislain wrote: ↑Tue Aug 29, 2023 9:56 am To have a light clutch, I use american Barnett bonded plates an a PES pressure plate ....no need to tight hardly springs , and never have to readjust clutch ...
They are now more than 30000 km old, and don't show any wear ... 362608811_6305619232825783_1475491886058579117_n.jpg

Thanks, unfortunately my options are limited now I am back in NZ, due to shipping costs, but I will try different plates before trying an extra plate conversion etc. The last plates I had worked fine (just 4 of them) until the tangs got chewed up, so it is possible.

For the record “fairdeals2017” on ebay says it supplies friction plates but they don’t fit and they refuse to take down their listing or provide refunds to those mis-supplied hence ripped off (me).

https://www.ebay.com/itm/144965222844?h ... Swthlj~TTK

SteveS · Post by **SteveS** » Wed Aug 30, 2023 7:07 pm

Hi

Sorry, going slightly off topic.........................

Ebay can be a good source for parts but as you've found out the hard way there are some unscrupulous sellers that know their products are inferior and/or sub-standard. Personally I've had recent issues with an aluminium petrol tank from India that was not fit for purpose, tried to get a refund but it would have cost me nearly as much as the purchase cost in return shipping so eventually gave up. I left negative feedback with a detailed explanation concerning the faults with the tank so that other potential buyers were aware. Ebay took down the feedback???

For the record “fairdeals2017” on ebay says it supplies friction plates but they don’t fit and they refuse to take down their listing or provide refunds to those mis-supplied hence ripped off (me).

'fairdeals2017' were originally shipping directly from India, they now have a warehouse in Birmingham and state parts are 'UK supplied' which is true but what they don't tell you is that their 'dedicated production facility' is in India i.e. parts are made in India, shipped by container into the UK and then sold on internationally as 'UK supplied'

I get exasperated that Ebay allow sellers to punt these non-fitting often dangerous items on their site. Below is a link to YouTube video regarding Indian made replica BSA M20 girder forks. The host of the video is so abjectly pi** off with the quality of the forks it almost makes you laugh

Indian made girder forks Are they any good?

KiwiB44 · Post by **KiwiB44** » Thu Aug 31, 2023 9:18 pm

SteveS wrote: ↑Wed Aug 30, 2023 7:07 pm Hi

Sorry, going slightly off topic.........................

Ebay can be a good source for parts but as you've found out the hard way there are some unscrupulous sellers that know their products are inferior and/or sub-standard. Personally I've had recent issues with an aluminium petrol tank from India that was not fit for purpose, tried to get a refund but it would have cost me nearly as much as the purchase cost in return shipping so eventually gave up. I left negative feedback with a detailed explanation concerning the faults with the tank so that other potential buyers were aware. Ebay took down the feedback???

For the record “fairdeals2017” on ebay says it supplies friction plates but they don’t fit and they refuse to take down their listing or provide refunds to those mis-supplied hence ripped off (me).
'fairdeals2017' were originally shipping directly from India, they now have a warehouse in Birmingham and state parts are 'UK supplied' which is true but what they don't tell you is that their 'dedicated production facility' is in India i.e. parts are made in India, shipped by container into the UK and then sold on internationally as 'UK supplied'

I get exasperated that Ebay allow sellers to punt these non-fitting often dangerous items on their site. Below is a link to YouTube video regarding Indian made replica BSA M20 girder forks. The host of the video is so abjectly pi** off with the quality of the forks it almost makes you laugh

Indian made girder forks Are they any good?

Thanks Steve, I certainly won’t use “fairdeals2017” again, and for the record….. the over length clutch springs came from Draganfly! I might be able use them if the take a permanent “set” after over compressing them in a vice or similar, but for now I have re-fitted the old springs (even though they need replacing due to being different lengths).

The B44 engine is running well and passed its “WOF” (aka mot) yesterday, once the 3 new gears and new indexing parts are fitted and clutch improved it will be ready for the NZ rally season, albeit its rideable now.

KiwiB44 · Post by **KiwiB44** » Thu Aug 31, 2023 9:20 pm

ghislain wrote: ↑Tue Aug 29, 2023 9:56 am To have a light clutch, I use american Barnett bonded plates an a PES pressure plate ....no need to tight hardly springs , and never have to readjust clutch ...
They are now more than 30000 km old, and don't show any wear ... 362608811_6305619232825783_1475491886058579117_n.jpg

Thanks I will have another look at sourcing “barnett” friction plates.

Mark Cook · Post by **Mark Cook** » Wed Sep 06, 2023 9:44 am

I tried to buy Barnett to stock.
They were so expensive I suspect I could have custom plates for less.

Whilst you were here I could have guided you to the best sources if we never had the parts.

Mark

KiwiB44 · Post by **KiwiB44** » Wed Sep 06, 2023 12:41 pm

Mark Cook wrote: ↑Wed Sep 06, 2023 9:44 am I tried to buy Barnett to stock.
They were so expensive I suspect I could have custom plates for less.

Whilst you were here I could have guided you to the best sources if we never had the parts.

Mark

Thanks Mark, things got a bit hectic during my uk hols, we toured around scotland (right up to John O’groats) and just ran out of time to source everything I needed, hopefully I have found a source of friction plates in OZ, time will tell! They are in their way, but I will have to find a plain plate elsewhere if I go the extra plate route. Link below. https://superbikesupply.com.au/collecti ... 9104439411

I noticed the Barnett plates are not much thicker than Surflex, so still thinner than oem BSA.

A test ride today revealed I have a return of jumping out of top gear and back into 3rd once I get to 45mph, but it is all good with the other gears

. Two steps forward and one back.

I have managed to fix a top gear issue on this bike before, by elongating the screw holes in the index spring by 2 or 3mm, to ensure the spring gets fully into the top gear notch on the camplate, instead of sitting half way down the notch with the dogs fully engaged and the camplate unable to rotate any further. I did check for this issue before putting the cover back on but I will tear the box down again

and if necessary try this same mod again, with the new layshaft gears just fitted, albeit its a shame to mod a new spring.

I find cleaning the cover faces of gasket goo, doing the ign timing, checking gear engagement etc makes the gearbox strip and rebuild take a while…….its tricky without taking the primary apart as well.

Its not a great mod to have a spring that it is not held in place by the two screws as securely as it should be. The new PES spring is of course correct dimensionally but it does seem I need to “fettle” the spring to suit the set of parts I have. I guess something in the box is still out of whack

ghislain · Post by **ghislain** » Wed Sep 06, 2023 6:12 pm

https://www.ebay.com/itm/201403830533?h ... R_ydyrfNYg

Hope this helps !

KiwiB44 · Post by **KiwiB44** » Mon Sep 18, 2023 9:50 am

I have received some Barnett plates, these are slightly thicker than Surflex (I think). They actually have less friction material which was unexpected. They measure 0.130’ thick.

The Surflex plates shown slip even with the springs over compressed, but look pretty oil soaked. They measure 0.110’ thick.

A possible future project might be to modify the incorrect (blue coloured) plates I received from an ebay supplier, as they are nice and thick as per oem (see pic), and have a suitable ID and OD. But of course the metal used could be “cheese” like the unbranded plates I bought locally and where the tangs were hammered and which failed after a few hundred miles.

I am waiting for a new mainshaft sliding gear, i5 should be here this week, to (hopefully) help fix the top gear issue I have, but it will have a used but visually ok top (sleeve) gear to mate with. Fingers crossed. The old sleeve gear dogs were obviously munted.

FGF · Post by **FGF** » Wed Sep 20, 2023 2:11 pm

Hello ,
Since i fitted Barnett plates as '' Ghislain '' told me to do , i 've no splipping at all ...( B50 SS - MX cam)
The friction radius is greater than the surflex one , as it 's possible to see
on the photos.
The friction material is doubtless a best quality one to support a higher pression. ( ID Barnett < ID original )
Francois

KiwiB44 · Post by **KiwiB44** » Thu Sep 21, 2023 1:10 am

FGF wrote: ↑Wed Sep 20, 2023 2:11 pm Hello ,
Since i fitted Barnett plates as '' Ghislain '' told me to do , i 've no splipping at all ...( B50 SS - MX cam)
The friction radius is greater than the surflex one , as it 's possible to see
on the photos.
The friction material is doubtless a best quality one to support a higher pression. ( ID Barnett < ID original )
Francois

All good points, even better would be making them oem thickness!

Do you find 4 barnett plates is enough?

KiwiB44 · Post by **KiwiB44** » Thu Sep 21, 2023 1:27 am

I had to make a simple tool to press the sleeve bushes out, to use on the gear going back in the bike. You can maybe see the munted (female) dogs on the old gear gave that gave trouble eg jumping out of top.

I didnt fit new bushes as the old ones appeared ok, and I didn’t want the bike off the road again whilst waiting for parts to arrive. I was surprised the bushes did not get ruined during the swap over.

The used sleeve gear I bought was probably only sold because the seller thought it not worth much with worn out bushes

(yep I am cynical when it comes to buying used parts). I hope I am right and the dogs are ok on it.

Next challenge, apart from getting the cluster back in, there were only 24 of the 3/16” rollers in the clutch, should be 25. Not sure how hard it will be to source these in NZ.

Mark Cook · Post by **Mark Cook** » Thu Sep 21, 2023 9:05 am

A better option than the split bush.

https://pesltd.uk/?product=41-3045

[url]https://pesltd.uk/?product=40-3206[/ur]

Mark

twinshocker · Post by **twinshocker** » Thu Sep 21, 2023 9:40 am

If you can´t get the missing 3/16 roller you can put in a smaller one (i.e. 4mm) just to fill the gap

KiwiB44 · Post by **KiwiB44** » Thu Sep 21, 2023 8:55 pm

twinshocker wrote: ↑Thu Sep 21, 2023 9:40 am If you can´t get the missing 3/16 roller you can put in a smaller one (i.e. 4mm) just to fill the gap

Good idea, as it happens I found a few 3/16” rollers 3/8 long, and managed to machine one down to 3/16” long at the expense of a few chinese carbide tips

At least I know the modified roller is fairly hard, but I will get a new set of rollers anyway, just in case.

KiwiB44 · Post by **KiwiB44** » Thu Sep 21, 2023 9:12 pm

Mark Cook wrote: ↑Thu Sep 21, 2023 9:05 am A better option than the split bush.

https://pesltd.uk/?product=41-3045

[url]https://pesltd.uk/?product=40-3206[/ur]

Mark

Thanks Mark, I will put the rollers on my PES “shopping list” (I need to bundle a few things together to make shipping to NZ economic). At the moment I am just trying to get this bike to successfully complete a few rallies this summer, fixing it “properly” will be done over time.

I am very pleased with how (just) fitting the PES piston has worked out

, as opposed to doing a complete strip down and fitting a new piston and sleeve etc. No smoke no rattles etc, fingers crossed it stays that way during running in

Gearbox goes back together today with a bit if luck. Would be easy if I did not have to make diy tab washers that I forgot to order