finished cylinder Welcome to NZ Cylinders

Aprilia, Ducati,Honda, Husqvarna, Kawasaki,KTM, Maxter,Suzuki, Yamaha, Porche, Polaris, SeaDoo, TM



Our plating process

Cylinder honing

Assembly tips

Cylinder head machining

Avoiding problems

NZ work order

Australian work order

Notes for Australian customers

Champions gallery

Exchange cylinders

Contact us

This page is a work in progress; here I will add information about various problems specific to an engine.

Suzuki RM250 ring catches in inlet window when fitting cylinder; also applies to some other engines. Ring end opens into port when installing cylinder; use a suitable tool to guide ring into cylinder. Do not force cylinder as this can damage plating/ring/piston.

rm250 port


Honda CR250

If used in Karts they generally require more piston clearance also earlier cylinders with auxillary exhaust ports may sieze on the bridge between these ports. Remedies that have been tried are

1:- polish a little extra clearance into the bore at this point.

2:- file a little more cam profile onto the piston at this point


Aprilia RS250

Piston seizure, especially on front cylinder.

Perform the usual checks:- jets block or incorrect size, ignition timing, old fuel or incorrect octane rating.

We have also noted the following:- heads machined (compression too high), muffler blocked, stingers modified (too small), oil system not bleed, blocked radiator.

Also watch for:- fuel tank vent blocked (mixture go lean after a distance depending on speed and how full the tank is), oil tank cap replaced with a cork (Chernobyl come to mind) crankshaft seals (see KTM200)

Suzuki RG150 use a one way valve in the oil line, I don't know if the RGV250 or RS250 use these, if you can confirm please let me know.

Suzuki RG150

Following rebores by several different companies, every one resulting in an exhaust side seizure even with far too much clearance, a replacement cylinder was bought to us for a rebore. When the engine was reassembled it was noted the the exhaust bridge oil injection fitting on the replacement cylinder contained a one way valve. Problem solved.

KTM 200

A used bike was traded with a seized cylinder, a new cylinder was fitted and it was sold, after a few hours it seized. It was returned to the dealer, another new cylinder was fitted.
It was then resold, after a few hours it seized. This time it was checked for all of the usual faults. We welded and replated the cylinder but after a few hours with another new owner it seized.

There is a pattern here, after some more checking a small air leak at one of the crank seals was found, another replated cylinder was fitted. It has now given several years service without a problem.






| ©2010 DG Engine Services