[AsFarAsIGet]

Hi all!

The next step in my overhaul is to split the engine and replace the main bearings and the floating bush in the big end. In the progress of dismantling I realized that my crankshaft has about 2-3 mm horizontal play. Is this ok, or is this something that I should worry about? If so, any input on what to look for?


Best regards / Ruaridh

[stinkwheel]

Is this before or after the engine sprocket has been removed? it'll tend to pull everything into the bearings when tightened down.

[AsFarAsIGet]

Is this before or after the engine sprocket has been removed? it'll tend to pull everything into the bearings when tightened down.

This is after the engine sprocket was removed.
I tried to attach a video but didn't get that to work...

So hopefully it should be ok? 

[AsFarAsIGet]

Zipped video of the crankshaft play.

Can be viewed if downloaded and unpacked.

[stinkwheel]

I don't know what the spec is on lateral play but when the engine sprocket is in place, it pull everything over to the left side anyway so there isn't any movement in use. I'll admit I don't know enough detail to tell you for sure it isn't a problem but I'm sure someone else will be along soon with a more definative answer.

Be interesting to see if there is any sign of abnormal wear once it's apart. Also if the thrust washers on the crank and the distance pieces between the two drive side main bearings are as they should be. I would imagine that as long as the timing side bearing inner race is fully under the rollers and the crank webs aren't touching the inside of the casing, it wont cause any issues. You are stripping it all anyway so excess wear somewhere should be noticeable.

I had play on my 350 crank when I last rebuilt it and it turned out my drive shaft was loose in the crank web. Interestingly enough, it had shown no sign of this because it was being pulled up tight by the engine sprocket nut when it was all assembled. I was only splitting it to clean out the bits of piston where it had snapped a valve then hammered it through the piston. Landed up having to fit a rebuilt crank but I do wonder how long it would have taken to notice a problem. Probably not until the woodroffe key sheared and spun the shaft. This isn't a problem with yours, your whole crank is moving, not just one side.

[AsFarAsIGet]

Thanks for the reply!

My hope is to split the crankcase today and inspect for wear. But first, I somehow have to get the timing pinion off the crankshaft. Unfortunately I don't have the specially designed puller for the job.

Any suggestions in how to get the pinion off the shaft without the puller?

I have also tried to figure out how to separate the two crankcase halves. Is it just brute force, or are there any special tricks that can come in handy?

/ Ruaridh

[stinkwheel]

Heating the pinnion up and prying it off with two large flat bladed screwdrivers risks damage to the crankcases. Using a puller does not... So I suppose it depends on your attitude to risk.

I've always been able to tap the crankcases apart with a rubber mallet without a great deal of difficulty. Getting the head off on the other hand has presented me with no end of problems over the years.

[AsFarAsIGet]

I managed to redesign the puller I used to remove the timing pinion from the timing shaft and voila! The pinion fell off the crankshaft almost by itself

Now to the splitting of the crank case. So far I have tried with a little heat at the backend top part of the engine, but no success. Any other suggestions where to get started? Attached is a pic of the place I have tried so far using a piece of wood and a hammer.

/ Ruaridh

[stinkwheel]

I've never really had to pry on a bullet crankcase. I suppose the first thing to check is that you have all the bolts removed (see pic). I generally start tapping at the seam all the way round with a rubber mallet then it eventually gives a slightly hollow sound which means it is moving.

The correct answer is probably using another puller attached to the crankcase and bearing against the end of the crank. I used a harmonic balance puller to split the last engine I did (a little Russian 2-stroke).

I'm sure i saw someone, possibly Bullet Whisperer? use stanley knife blades tapped into the middle of the paper gasket at a top corner to start cases splitting. Never tried that myself. I'd wear gloves and eye protection if you decide to try that because tapping on hardened steel blades can cause shrapnel.

[AsFarAsIGet]

I used a harmonic balance puller to split the last engine I did.

Harmonic puller ordered.
Now I'm hoping for a rapid delivery and with some luck I will continue the splitting of the crankcase later this week 

[Adrian II]

That notch between the crankcase halves which you arrowed is actually the space for the magneto strap on the old Redditch Bullets. The Indian factory kept it until the very end of the iron barrel production despite the fact that magneto ignition hadn't been fitted for years. 



A.

[stinkwheel]

Harmonic puller ordered.
Now I'm hoping for a rapid delivery and with some luck I will continue the splitting of the crankcase later this week 

Hope it fits. If not, you can still use it by adding a little ingenuity. Extra plates, long bolts and suchlike. I used a piece of scrap plate and some allthread to make mine fit the wee russian bike.


I must say I'm surprised it's together that tight. I wonder if it's been split before and someone used an inappropriate gasket sealant on the joint.

[richard211]

The way I normally split the crankcases, is by placing a small piece of wood against the timing side shaft of the crankshaft and then strike the piece of wood with a mallet / hammer. This is done with the crankcase in the upright position. It helps in situations where silicone sealant used. Once the crankcase of the timing side is off. The drive side of the crankcase usually requires a bit more effort because the ball bearing on the drive shaft of the crankshaft is a tight fit on the drive shaft. Having someone to support the timing side shaft of the crankshaft and hold the left side of the crankcase upright does help a lot, while the same procedure of using a piece of wood placed against the edge of the driveshaft (with the rotor nut installed to prevent damage to the threads) and then striking the piece of wood with a mallet / hammer.

[AsFarAsIGet]

Time for a short update!

Harmonic puller delivered a few days ago and today I finally had time to take care of the engine. It came apart real easy and now the next step is to get the old bearings out and the new in place. Any suggestions on how to get the old bearings out?

However, it seems as though water has made its way in to the bearings causing some rust on the inner race and crank shaft on the drive side. In the photos attached I believe that I see signs of wear on the drive side of the shaft. The inner race on the drive side is a little less than a snug fit, it doesn't wiggle but it slides on really easy. What would you recommend? Should I replace the shaft at the same time as I replace the bearings and inner races or do you think it suffices to change the bearings and inner races?

Also turns out that the inner race on the drive side hade a bit of a fault from the factory...

Best regards / Ruaridh

[stinkwheel]

That's peening of the bearing race. Most likely a combination of under-oiling/lack of oil changes and excessive low rev lugging of the engine causing it to thump against the bearing race. People like to thump about on them at low revs in a high gear but there engines should really be revved, this is why. I have one just like it.


Removing the bearings is easy. Just remove the seals and circlips and put the crankcases either on top of the stove or in the oven. Once hot they will either fall out on their own or you can pick up the whole thing with some thick gloves on and tap it flat against a wooden surface and they will fall out.

In terms of the fit on the shaft, all depends on if it's the shaft that's excessively worn or the inner race that's a poor fit. I'd clean it up with some scotchbrite. Looks like it may have spun slightly? Measuring it with a micrometer would be the ideal. Or just seeing how the new bearing fits, the old one clearly had a hard paper round. Using a bearing fit compound might also be an option if it's looser than you are happy with but doesn't have excessive play.

Replacing the shaft is a bigger job, if you are going to split and reassemble the crank, you then want to consider if you want to do other things while you have it apart. Do you want to swap out the floating bush? Steel conrod? Needle roller big end? How does the cost of doing the work compare to a service exchange?