There are many such cases for various reasons where we really want to reassemble the engine with the current cylinders. In such a time of need, a professional store for internal combustion engine machining can do a wonderful job. For example, it is possible to repair a cylinder that has already been oversized to its full size so that a new STD (standard size) piston can be installed. In other words, by making sleeves, it is possible to get the piston size back to where it was. Let us focus on the relationship between pistons and cylinder sleeves.
The cylinder's inner wall is no longer good due to seizure and rusting.
When the condition of the pistons and cylinders deteriorates significantly due to severe engine use, the engine may be reassembled by boring and honing the cylinders to fit slightly oversized pistons with a slightly larger outside diameter.
Although 4-stroke engines are less likely to seize than 2-stroke engines, rainwater can flow into the cylinders when left unattended for long periods of time, causing the piston rings and cylinders to rust and stick together. There are also cases where kit parts are purchased for engine tuning, etc., and the cylinder sleeves are removed and oversized sleeves are installed.
In any case, whether it is a 2-stroke or 4-stroke engine, repairing the cylinder side can open up new avenues, which is something that fans of old motorcycles should know about.
When the oversize pistons are gone, you're done!
Modern motorcycles do not have oversize pistons, and if a problem should occur, the standard practice is to purchase a new piston and a new cylinder as a set and reassemble them. Under such circumstances, there are cases where special parts constructors are selling oversize pistons. In particular, there are many cases where oversize pistons are sold only for popular models that are in demand. However, it is certain that there are fans who want to drive even unpopular motorcycles for a long time, and it is the internal combustion equipment suppliers who can realize such feelings.
At iB Inoue Boring, we went back to the drawing board when oversize settings were no longer available and undertook sleeve production in STD sizes. For 4-stroke engines that press-fit simple tubular parts, iB Inoue Boring also specializes in manufacturing multi-hole sleeves for old exhaust ports and scavenging ports.
Even unpopular models can be commissioned with confidence.