piston kits supplier help please

[Wookster]

Afternoon all,

I’m in the process of rebuilding a 1976 cb500t, I’ve found that the bike had only been running on one cylinder and scored up the bore pretty badly so I’m looking for new pistons and rings but my engine builder is having trouble sourcing them, could some one point me in the right direction to a UK supplier if possible please ( not sure if I need to go over size and not checked the bore diameters yet.  Thanks for any help.

[Trigger]

These are not easy to get hold of in the UK. Over the past 5 years i have built 2 CB500T engines and have had the pistons sent from the USA. CMS do pistion's for the CB500T but cost about £80 each and then you must buy the rings at about £60 each, so if your looking at two piston's and rings, you looking at £280 to £300. The states is a lot cheaper.

[Wookster]

Excellent trigger, did you get them from ebay then or do you have any contact details of the chap you used please as I'd like to use someone reputable, thanks again.

[Trigger]

The last set i got was from Western Honda in phoenix. I have just sent them a mail but, you will have to find out if you need over size first. I will also check with some German dealers.

[Trigger]

Found some aftermarket rings at a good price;
http://www.ebay.co.uk/itm/like/380865828843?limghlpsr=true&hlpv=2&ops=true&viphx=1&hlpht=true&lpid=108

[Wookster]

Lovely, thanks for your help Trigger!, I have seen John Oldham might have the rings but like you say I need to check the size of the pistons as they are.  There are no markings on them as such ie +0.2 or anything, any idea what the std size piston diameter is and I can go from there, I'm thinking perhaps I could getaway with a hone and new rings as the pistons are pretty good.

[Trigger]

There are two sizes listed: 70.50mm with part number 13103-375-003
                                          70.75mm  with part number 13104-375-003
You will have to work out from the engine number which is for your bike.
You said you had a engine builder on this. He/she should have all this information and be able to advise on what is required for a top end re-build.

[paul G]

This guy is worth a shout I have had a few bits from them, great service.

http://www.imdpistons.com/

[Wookster]

Thanks Trigger,

I did do some searching and came up with 70mm as std, problem is the engine builder if he can’t get hold of the pistons he leaves you to find them so I’m kind of doing this homework and he’ll rebore to suit.  I will have a look at the pistons to see what size they are as well, the engine code is cb500E XXXXXXX, but I’m hoping that I can getaway with just new rings.....well that is the plan anyway!.  I’ll give IMD a call and see what they can do, so thanks for that.

[Trigger]

I have been on the Honda Twins forum and the lads say it is not that easy to get hold of piston's for the CB500T any more. Found these in he states:
http://www.ebay.co.uk/itm/1975-1976-Honda-CB500T-CB-500-T-CYLINDER-PISTONS-12100-375-000-13101-375-003/221374073632?_trksid=p2045573.c100033.m2042&_trkparms=aid%3D111000%26algo%3DREC.RVI%26ao%3D1%26asc%3D20131017132637%26meid%3D5971281608730668515%26pid%3D100033%26prg%3D20131017132637%26rk%3D3%26rkt%3D4%26sd%3D261384248410

[Wookster]

Hi Trigger, thanks for that, after lots of working out I have managed to find replacement rings as the pistons eneded up being good, just needs honing now...I did however find a bent exhaust valve!.  Thanks for the pointers everyone, not sure it's solved just yet!.