P1KL3 wrote: ↑Mon Mar 11, 2019 5:28 am
James,
Do you remember roughly how long BDK took to arrive?
Dylan.
No I don't remember - sorry. However, it does not stick in my mind that delivery took any longer than it should. I suppose if you ask the question, you may get a better idea (i.e. make sure the parts are actually in stock and can be sent immediately).
Here is some info on the parts I used or have since discovered:
Conrods - There are a few different KX125s which used conrods with identical measurements to the standard KR-1 conrod. I used 13032-1189 (which superseded 13032-1194). The dimensions are the same as the KR-1 conrod, but the '1189' conrod weighs about 25g more. Also, I found that when fitting the crankshaft into the engine casing, the big end of the conrod touched the inner surface of the crank case. The interference was not enough to stop the crankshaft from rotating - I could only just feel/hear the conrod touching. This was soon sorted by about 10 minutes' work with a Dremel Multitool with sanding band attachment - the amount of material to be removed was quite small. I daresay I could have removed a small amount of material from the outer surface of the conrod big end instead, but it was a bit late with the crankshaft already assembled!
There are also 'Long' brand aftermarket conrods which I have found to be quite good (but haven't tried in a KR-1) - these are made in Japan and sometimes appear in Mitaka and Pro-X boxes. However, the bearings supplied with these conrods are
sometimes inferior (they may have a lesser number of rollers). Whatever conrod you use, check the thickness of material at the big end eye and compare with a standard KR-1 conrod to see if any removal of material will be required.
Big end bearings - These are a very common size (22-29-17) and there is a choice of different types. I used 15-roller bearings with PEEK-coated flat cages which I got from The Two-Stroke Shop (no longer in business, I think) - these bearings had been made especially for the shop and were promoted as a good quality bearing at a decent price (no complaints from me so far!) - mainly intended for use in high-performance Yamaha RZ motors I believe.
Alternatives I know about are Pro-X bearing 22.222917F and Yamaha 93310-523D2, which are both flat-cage bearings with 16 rollers. There are other alternatives, but try to buy known brand bearings with as many rollers as possible.
Small-end bearings - These are also a common size (16-21-20) and there is a lot of choice (OEM from all of the 'Big 4', Wiseco, Pro-X, INA etc.). Again, try to buy a known brand with no less rollers than original and you should be fine.
Big-end shims - These are 22-37-1.0 size and are a fairly common size for performance two-stroke engines. One example is Yamaha 90209-22248, but I'm pretty sure the same size is available OEM from all of the 'Big 4', as well as Wiseco, Pro-X etc.
Left-hand and inner main ball bearings (3 required) - These are a fairly common type (83A916C - size 25-55-15 with pin), used in a number of different bikes. I found some genuine Koyo bearings at Marksman Industrial for a good price and it looks like they are still available:
https://shop.marksman-ind.com/83a916csh ... 0025-p.asp
Otherwise you can buy Yamaha 93306-20577 or Pro-X 23.83A916C, which are the same.
Right-hand main ball bearing (1 required) - This (Type 83406) is based on the very common 6305 bearing (size 25-62-17), but has a locating groove and a pin. I had a little difficulty finding these when I built my KR-1 a few years ago, so I bought a 6305NR (which has a groove, but no pin) and had a pin inserted.
I had thought this bearing was the same as Yamaha 93306-30508. That part number has supposedly been superseded by 93306-30549, which is NOT the correct bearing (it is the same size, but has a 'dimple' instead of a pin, which is not in the correct place).
I have since discovered that Suzuki 09262-25097 (RGV crankshaft bearing) is the correct type with groove and pin. There is also Pro-X 23.83406 as another alternative.
Oil seals - These can be bought as a set from BDK, PJME etc. or individually from Pro-X suppliers. The left-hand seal presently available is a little different in that it hasn't got the raised locating ridge of the original seal (92049-1302). Basic dimensions are as follows:
Left-hand - 25-50-10
Middle left & right - 25-55-10
Right-hand - 25-62-8
Let us know how you get on, or if you need more info.
Regards,
James