Hi All

I’ve visited this forum as a guest many times and found loads of useful information, and as this is my first post, I hope I’m not teaching grandma to suck eggs:

Some information on the 43F, which may be useful

Models 1984/85/86 - 43F

Con rod width = 20mm, Little end bore = 22mm, Big end bore = 42mm
Big end Bearing 34x42x20, (34 inner, 42 outer, 20 wide)
Crank pin 34mm diameter, 74mm long
Two 1mm washers each side of the connecting rod big end

Later Models
Con rod width = 22mm, Little end bore = 22mm, Big end bore = 43mm
Big end Bearing 35x43x22, (35 inner, 43 outer, 22 wide)
Crank pin 35mm diameter, 74mm long
No washers each side of the connecting rod.

For Models 43F: if you cannot get a new connecting rod, (1984/85/86 style):
Here’s an idea:
Use the newer style con rod, without the 1mm washers.
With an old style crank pin
This will require a big end bearing of 34x43x22 – does such a bearing exist?
Well yes - it’s a Suzuki bearing part no: 09263-34005.
May need to rebalance crank as the con rod will be slightly heavier!

If you’ve got a later model; new connecting rod, crank pin and bearing, fitted; £135 from:

Grampian Motors, Musker Street, Liverpool, L23 0UB, tel 01519315009, and he will do it while you wait! He will also pull/replace the timing gear if you have a new main bearing to fit.

List of 43F engine bearings/seals:
Right Hand
Main Bearing = 6307 – type C3 – 35x80x21, (inner, outer, width).
Clutch Input Shaft = 6305N – 25x62x17
Balance shaft = 6305 – 25x62x17
Gearbox Top = 6004 - 20x42x12

Left Hand
Main Bearing = 6306 – type C3 - 30x72x19
Balance shaft = 6305 – 25x62x17
Final drive output shaft = 6305 – RS1, (buy 2 seal and remove 1). - 25x62x17
Gearbox Top = 6004 – RSH, (buy 2 seal and remove 1). - 20x42x12
Balance shaft Seal = 20x40x3 R21
Final drive output shaft seal = 25x40x6 R23
Gear change seal = 12x22x5 R23

Use; SKF, FAG, Timkin, NTN, KOYO, NKE, IKO, all good

Hi!

Thank you for the detailed info! I have a question, though.
I am currently working on a 1986 XT600 43F, and I have to replace the two main bearings.

I heard that these two are not only clearance-graded, but also have some temperature-tolerance grading, and any other bearings are not capable of handling this load. Have you used replaced, non-original (like SKF) bearings in XT-s? Or do you know about XT-s running with replaced main bearings?

I wouldnt really want to buy originals for $100 each, but if they are the only solution..

Greetings

Szatyorful

Hi
When I stripped out the old main bearings they were NOT type C3 - they were standard KOYO 6307 & 6306.
So they could have been original, (as the engine did not look to have been stripped before)

I fitted type C3, (having read the info on this forum), but I don't think you need to get a temperature resistant type, (if they actually make one), as a decent manufacturers bearing will tolerate around 120 deg C, (248 F).
(BTW Type C3 is a normal bearing with slightly coarser tolerances)

I guess as long as you use a decent oil, that should keep the bearings oiled and cool

I used SKF bearings and they were around £12 each, (say $15).

Well if you use them since a while and they are not noisy then they are good, I think. How long has it been since you replaced them? Otherwise, it simplifies the question that I could not find original left hand bearings for the 43F, and the SKF warehouse is 5 minutes from here

Hi

Well they have only been in for a few 'run in' miles, so I can't say what they are like long term !

But if you think about it; Yamaha don't manufacture bearings - they MUST buy bearings from a bearing manufacturer, so if you use SKF, KOYO, FAG, Timken etc etc, they have top notch specs, and should be OK.

The other point is; these main bearings are fairly hefty bearings, when you compare to the big end bearing, which is quite a small roller bearing, so if that is OK then you would think the main bearings should be well up to the job.

As a bit of interest here's my crank in bits:~

http://i58.photobucket.com/albums/g266/ ... qpygeu.jpg

http://i58.photobucket.com/albums/g266/ ... xtgmzw.jpg


Regards

PaulW

Hi

Thank you, good points there.. and if there is any problem with them the engine can be stripped again, so tomorrow is the day for shopping at SKF .
That crank looks great beautiful piece of machinery. How did you pull the timing chain gear and the bearing? And how are you gonna put it back? Just heat them a bit and they slip on?

Regards

Szatyorful

Hi

Well I took the crank assembly to a small engineering workshop in Liverpool, who specialise in Yamaha, but when he pulled the crank apart, he realised that it was a 1984 model and his stock only covered 1989 on. The con rods were changed on later models, (2mm wider and a larger crank pin and bearing). So he gave it back in pieces !!

I had a tough job finding a new con rod, crank pin and bearing, to 1984 spec. In the end I had to go to a Dutch outfit who specialise in 're manufacture' of old parts, they weren't cheap though!

(http://www.cmsnl.com/)

I had previously tried to remove the gear with a fairly hefty puller - but it just would not budge! The Liverpool guy said he had a hydraulic puller for the gear and a 30 Ton press for the crank pin! So when the stuff arrived from Holland, back to Liverpool for reassembly - took him about 20mins while I waited !!

Regards
PaulW

How come you never used your own idea of a 1VJ rod and a suzuki bearing on a 34K crank pin?

Well by the time I'd realised it could be done - I'd already ordered the stuff from Holland !!

That would be a decent enough reason