I've bought a spare engine with no exhaust / carbs etc. The engine number starts 1HX, well, I say starts, thats all there is, just like it does on the one in my 3LN. Which got me thinking, what is the engine start number on the 2kr's? and have I indeed bought a 2KR engine. Is there any way I can distinguish between engines externally? thanks
Does it have a number like this? .... if so u can match it here ..... http://2fiftycc.com/index.php?resources/yamaha-fzr250-model-information.230/ This is a 3LN motor
Not always GI. I have mine on the front of the engine! The top plate is blank. And from my PPSR check, it's the original engine. I'll take a pic later. Though my 2kr has 1HX on the top plate. Maybe my 3ln was a warranty engine swap sometime before import.... Does it have the stator cover on? I found that my 3ln had more magnets inside than the one on my 2kr. Though this isn't a true indication as the can be swapped.
Both my bikes are 3LN1s and have the number on the plate as above and correspond to the original frame number as below
I don’t know if the FZR 250 was ever officially imported into Aus, in the UK it only came in as a grey import, so as long as it had a chassis number it was okay - the engine numbers never got stamped. My 3LN is the same as all the others in the UK with just the factory stamped start number IHX, just the same as on the engine I’ve bought – see the attached photo. I assume my 3LN has a 3LN engine, but it may not have. Anyway, checking the magnets is great as it means minimal dissembly. I didn't know if there were any other sneaky little external changes, like for example the Kawasaki KR1 and KR1-s which externally look identical other than for one extra retaining bolt on the clutch cover! I know if the had a spin on oil filter for example then it’s definitely a later model, but like my existing 3LN engine it’s got the filter under the plate in the sump so again, it could be either I think Here are some more photo’s of it – apologies for the quality On similar subject, does anyone know what the actual differences between the engines are internally? I think there are a minimum of 4 broad groups here – maybe more: 1. 2KR 2. EXUP engines before 3LN (although these may be the same as 2KR) 3. 3LN early, with oil filter in sump plate 4. 3LN later, with spin on canister oil filter From the Japanese manual I’ve got for 3LN1 I can tell: The connecting rods on the 3LN1 are longer than previous (82mm vs. 80mm), the cams are different in terms of duration (difficult to measure) and the pistons are lighter and have gudgeon pins offset from central axis and I assume a different deck height to account for the longer rod. What else do we know?
Ok so I double checked mine. Seems I have the "1HX" prefix on top of my engine. No further digits. On the front of my motor: There it is just in front of the stator cover where the fairing mount is bolted into the block. On a side note my engine number and frame do not match. Perhaps it was changed by the importers or while in japan? Oh and the 250's were only ever sold in japan. All other countries were grey imports. That's why there is no English service manual!
i thought 1hx engines were only made in 88-89 and were 2kr,s.the only definite answer will be when you measure the bore and stroke.
interesting because this page lists the same bore & stroke for the lot - I assumed the different power figures was down to cam profiles & overlap - pre Exup 2kr ->less overlap and lower RPM values for both peak torque and power, 3LN1, 3 & 5 the same, 3LN6 & 7 lower RPM values than both 2kr and earlier 3ln's
Well, I've got to admit I didn't think bore and stroke were any different. But anyway, there I was scouring endless pictures of the two engines, counting fins on sylinders, bosses on cam covers etc whe it hit me like a peice of 4 by 2. The pre deltabox chassis engines, i.e everything before 3LN didn't mount of the side of the head, so they don't have 2 dirty great bosses for the mounitng bolts there. How did we miss it?? So that's immeadiate problem solved for me. Still be interesting to cataloge differences between variants, but I'm sorted for now.
Risky, the 1HX engine was originally made for the FZ250 Phazer as far back as 85, the Phazer carries 1HX as it frame number. The engine was then used in the FZR250 line up over the years. As for engine numbers, all IHX engine just carry this prefix and no actual engine number after it. The picture above of GreyImport's engine with engine number matching the frame number as obviously been stamped by a previous owner for some reason and after a fair few pints looking at the way it staggers! lol. But you would know an FZ250 motor straight away as they were painted black. By the way I do have a genuine parts book for the FZ250 Phazer if anybody needs any part numbers.
Actually, my 2KR has the engine number stamped on it too, and it matches the number on the frame too. It has "1HX" cast in the cylinder casing (just beneath the headers), with some other numbers on it. But, the 1HX, and the engine number is stamped on the crankcase, in the middle of the engine beneath the carbs. It is not painted black either. It is plain cast grey. Mine is a very early 2KR, one of the first 8,000 built going by the serial numbers. it has been just sitting there for the last 5 years, needing rings, i think, and a carb rebuild. (Or, it may be just parted out)
Thanks, although i have a set of standard size, 1HX-part number rings comming to me. They are genuine Yamaha NOS. Although i'm not really sure i want to start a rebuild at the moment. So i might have a set to sell as well if i part the bike out But good to know if i need pistons. Thanks
