yamaha ytm250

[leevarnado]

has anyone tried using a yfm250 cylinder and head on a ytm 225 engine.i was doing a little research and there's quite a few 250's that use the 225 connecting rod.or would it be possible to use a 250 sleeve in the 225 engine,i know boring the cylinder 1mm-2mm would be required,does anyone have any info on this.

[1984 honda 200s]

id like to know this too, or just a simple yfm225 cylinder and head...since mine may be blown..,, are thay interchangeable?

[leevarnado]

after a little more research.it looks like a timberwolf/beartracker engine might bolt right into a ytm225 frame.

[Yamada]

I think the 250 is the same cylinder, but with a little larger bore, like if you bore the cylinder to put a new piston. Check the bore x stroke specs.

[leevarnado]

timberwolf 250- 71x58...tri moto 225 - 70x58

does anyone have a ytm225 cylinder sitting around,if so can you take a look and see if there is enough material to bore the cylinder for the 71 mm sleeve .kibble white also make an oversized intake valve for the raptor 250,the ytm 225 uses the same intake valve .looks like megacycle and webcam still makes performance parts for the 225.

[LANGILLE88]

I am in the process of doing this modification. All the parts to do the job are on eBay as bran new cylinder with piston and rings all the gaskets plus valve seals for $145.00CDN shipped to my door. I have 2 '84 ytm225DXL engines. One is getting swapped out in my YFM200DXS but I'm taking the reverse from it and putting it on the YTM. The other I will keep as the YTM and I also have a reverse gear setup for it as well. I will post pics as I go through the steps of building it.

[LANGILLE88]

The heads are the same from '83 ytm200 to the '91 YFM250B and all the other four stroke Yamaha's back then. I'm not sure about anything after that but they are probably the same too from the BW,TW,TTR,XT and so on,

[El Camexican]

The heads are the same from '83 ytm200 to the '91 YFM250B and all the other four stroke Yamaha's back then. I'm not sure about anything after that but they are probably the same too from the BW,TW,TTR,XT and so on,

Heads are the same 200/225, but the cylinders and crankshaft/rods are different. I’m sure all of those cylinders allowed for at least 1mm of overbore, so that shouldn’t be an issue.

Going on Partsfish and comparing part numbers will answer a lot of questions. Yamaha was pretty good about using the same numbers for identical parts regardless of year or model.

[JWylde]

The cylinder from the yfm 225 as well as timberwolf and ttr2xx bolt right up however the pistons are different with the yfm/timberwolf being a lower compression piston the ttr is close though. You also need a chain auto tensioner and 2 or 3 o-rings that aren't included in the ebay kit.