View Full Version : Cylinder rebores in Auckland?

28th September 2005, 18:17
I've just got a new set of oversize pistons for my Yamaha Rd350lc, can anyone out there recomend somewhere to rebore the cylinders? I'd like to use someone that has bike experience in 2strokes, if anyone knows of any good 2stroke tuners that would be a great help to me aswell as I'm tryin to get the bike ready for the postclassic racing, thanks

28th September 2005, 19:12
Matey Im sorry I dont know of anyone in auckland anymore.

curious george
28th September 2005, 19:24
Matey Im sorry I dont know of anyone in auckland anymore.Nice one Frosty :spudwave:
Have a look in a kiwirider magazine, the is a place in Meremere that does it, with some warranty.
They wanted about $500 for one of my RGV barrels, the technique and product is supposed to be good, but I've not had any personal experience with them.
If you have no luck finding them, I'll look the number up for you, it's here somewhere

28th September 2005, 19:34
thanks George , I only need them rebored .25mm oversize from standard, they don't need resleeved or anything, I hope it's a lot less than $500 or they could be sitting for a while! thanks

28th September 2005, 20:42
Any good engine reconditioners should be able to do LC bores, as they are plain cast iron cyls. Which part of Auckland are you in?
What pistons do you have? ART (which are OEM Yamaha) or Pro-x are the best IMO Wisecos need LOTS of clearance as they are forged - IIRC around 6thou or twice that of the cast pistons. Read the instructions. The machinist will need the pistons to measure up for the clearance.
Don't forget to chamfer the ports - around 0.5mm so it doesn't snag the rings. Could always get it ported while it is apart...

28th September 2005, 20:58
Yeah,any reconditioner can do them,it's just a basic job for them.I use Carr Engine Services,they have done 2 stroke barrels for me no problem,I often see motorcycle barrels down there (my own is there right now) Steve is a good guy,always helpful to me and good for a yarn.He's on holiday at the moment and the guy running the place I have known for 25 yrs,and did all my machining before he folded his business and semi retired to help Steve.Neither has ever done a bum job for me,and that's in the hundreds of jobs.Wade is good too,but have seldom used him as my other guys are closer.Have had dealings with Engine Rebuilders all my life,a shit load of jobs have gone through them over the decades,and a few frustrations to make them a 3rd option for me....but I wouldn't diss them,they are pretty good.

curious george
28th September 2005, 21:19
Actually, I thought you wanted them plated, not rebored. My bad.
What Motu said then.

28th September 2005, 21:37
thanks for that motu, sounds like they can do what I'm after for now, hi Geoff, they are pro-x pistons, came from pro-flo in the states in less than a week, cost nz$290. all up with 2 new small end bearings and the shipping,postage and insurance which bumped it up a bit, I've just found it hard to get parts local so I thought I'd give them a try and they came thru pretty quick, one shop which has been pretty good for oem parts quoted me 3 months for an aftermarket top gasket set! Is there anyone you know who could do the porting? The engine in the race bike at the moment has been ported but the bore is 1mm o/s, so not much room left in them, but I have another 2 standard 350 engines and a 250 engine, so the new pistons are for a new build up with hopefully a new crank rebuild, I just need to find someone that can be trusted with the job, I'm sure they're out there Geoff ,I just need pointed in they're direction! thanks

29th September 2005, 14:56
Are they LC pistons or RZ/banshee ones? Both will work BUT if you are going to use RZ ones, you MUST file off the little tang on the bottom, that would otherwise catch in the boost port and bork your motor. There is a site somewhere with a piccie- have a dig around Alex's RD board. http://www.yamaha-rd.com/forum/topic-22300.html for one thread on this common topic
Porting, hmm. A tough call. I did have some porting specs, and I did have a Mota data file for the 250LC before the crash. I will see what I have in the archives.
Finding someone to do a good job on porting (in Auckland anyway) seems to be impossible to find someone who can do it properly and scientifically. They keep it quiet if they are around...
Lyndsay Knight in Pukekohe does all my work, and I can recommend him. Not the quickest, but always good. you could give him a call, although he is away for the next 3 weeks or so.
Other general info worth looking at:

Remind me later and I will dig out the LC info I have and put it up on my web page.