OzVMX Forum

Marque Remarks => Suzuki => Topic started by: bigk on January 04, 2008, 07:52:24 pm

Title: RM125A piston
Post by: bigk on January 04, 2008, 07:52:24 pm: Can anyone out there in Sushi land tell me who can supply pistons or what the alternatives are for RM125A. I need a 1.5mm OS (57.5mm).
Cheers,
K
Title: Re: RM125A piston
Post by: VMX Andrew on January 04, 2008, 08:01:04 pm: try serco ...they sell a wide range of oversize pistons that covers all jap bikes....
Title: Re: RM125A piston
Post by: oldfart on January 04, 2008, 08:35:23 pm: wiseco list 125 DS 1979-81
125 TS 1979-81
125 TC 1970-78
All having a 56 mm Bore X 50mm Stroke

56 std 449M05600 $108-00 as below
56.5 449M05650
57 449M05700
57.5 449M05750
58 449M05800 $118-00 price includes piston-rings -wrist pin and circlips
Title: Re: RM125A piston
Post by: 090 on January 04, 2008, 08:35:54 pm: Trailbikes of the same era might have more oversizes and may be the same shape. I did this on a TM125. I used something like a tc? 125.
Title: Re: RM125A piston
Post by: bigk on January 04, 2008, 10:28:17 pm: Tried Serco and the TC/TS thing, don't fit. They list RM125B onwards but no A model. Tried Pro-X,not listed either, tried a CR125 Elsinore piston, very close but different pin size. Someone who is into Suuki's must know the secret.
Cheers,
K
Title: Re: RM125A piston
Post by: Lozza on January 04, 2008, 11:18:42 pm: RM's were one of the first to go to the superior 54 X 54mm bore and stroke, to be a 56 X 50mm bore/stroke you probably have a 14mm pin. ProX has TS125 piston up to 58.50 in 0.25mm step and KE 125's have similar the TS has higher compression height and dome.
Title: Re: RM125A piston
Post by: LWC82PE on January 05, 2008, 10:04:03 am: try BB importers/bikes and bits importers in WA they can fax you a diagram for you to fill in dimensions and they will try match it up to a piston from their huge stock. i dont have their phone number right now but i could find it for you. they used to advertise in VMX magazine.
Title: Re: RM125A piston
Post by: TM BILL on January 05, 2008, 01:53:00 pm: RM 125A pistons were a one off 56mm std & 16mm gudgeon pin >:( there are usually loads on ebay because they only fit the RM 125 A :o
Title: Re: RM125A piston
Post by: oldfart on January 05, 2008, 03:11:43 pm: Not too sure on if this will work

Yz 125 1976-82 56mm-std 58 mm max 16mm pin
Title: Re: RM125A piston
Post by: bigk on January 05, 2008, 06:04:56 pm: Thanks all, I'll let you know how I go.
Cheers,
K
Title: Re: RM125A piston
Post by: Lozza on January 05, 2008, 08:49:55 pm: YZ's being reed induction probably have a window or a large cut away in the rear skirt.If it has a 16mm pin and you can't find a piston the you can always swap the rod for one with a 14mm pin.
Title: Re: RM125A piston
Post by: Tim754 on January 05, 2008, 10:30:17 pm: Big K , I got the Suzi parts book here for Rm125 models M, S ,A and B if you want to borrow. Tim754 (Elmore) PM if you do. Cheers.
Title: Re: RM125A piston
Post by: Oldrodder on January 05, 2008, 11:48:02 pm: Try this web site

http://www.pistons-online.com
Title: Re: RM125A piston
Post by: cyclegod on January 14, 2008, 09:18:13 am: This may interest you...

http://cgi.ebay.com/ebaymotors/Suzuki-RM125-nos-cylinder-set-1976_W0QQcmdZViewItemQQcategoryZ35581QQihZ007QQitemZ170185444473QQrdZ1QQsspagenameZWDVW
Title: Re: RM125A piston
Post by: bigk on January 14, 2008, 09:32:24 am: Almost got it soughted, just need to check a few measurements. Will post the results as soon as I confirm it will work.
Cheers,
K
Title: Re: RM125A piston
Post by: bigk on January 15, 2008, 03:44:42 pm: I have found that a Suzuki TS125R piston is very close and will work by either running it with only the top ring or shifting the bottom ring locating pin.
Cheers,
K.
Title: Re: RM125A piston
Post by: 090 on January 15, 2008, 06:04:49 pm: Nice one. Now that you mention it, i think that was the mod done to mine (move pin)
Title: Re: RM125A piston
Post by: Doc on January 18, 2008, 07:48:40 am: BigK..the TS125R piston are a 14mm gudgeon opposed to the RM125A 16mm. Does this R designation point to a different (later) R? '71 and '94 were the only times Suzuki used this designation. (that I know of)
Title: Re: RM125A piston
Post by: bigk on January 18, 2008, 09:50:59 am: Pro X part # 01.3007.200 listed to suit Suzuki TSR125. 16mm piston pin.
Cheers,
K
Title: Re: RM125A piston
Post by: Doc on January 18, 2008, 11:37:59 am: okay..TSR..makes sense BigK..JDM model..this is a '96 model TSR125. Is there any property differences between an aircooled piston and a water cooled piston?? I never looked as anything bar air cooled thinking the watercooled may heat up faster and require different tolerances.. :-\

(http://www.motorworld.jp/vehicle_image/image/img015/15263/large/CIMG9252.jpg?1185932701)
Title: Re: RM125A piston
Post by: bigk on January 19, 2008, 08:50:46 am: No difference in my experience in water cooled versus air cooled pistons. I have total confidence this piston will be fine. The bike is going to be raced, so it will be a good test.
Cheers,
K
Title: Re: RM125A piston
Post by: Doc on January 19, 2008, 12:45:47 pm: I love to hear someone with oodles of confidence! ;) Thanks for the tip BigK, I can start looking at a whole swag of pistons and rings I'd previously overlooked ;D
Title: Re: RM125A piston
Post by: GMC on January 19, 2008, 04:36:32 pm: Doc, I'm sure the alloy would be the same in all pistons (brand to brand)
Watercooled engines may have a different tollerance but this would be up to the guy that is boring it as they usually bore to suit the piston.
Title: Re: RM125A piston
Post by: Lozza on January 19, 2008, 07:59:11 pm: Usually there is no real difference between air and watercooled pistons.Water cooled models just run more compression, with todays piston/machining technology you have little to worry about.
To use these pistions in old TM/TS you might need to swap to an RGV rod or such.