Horrendous scraping when kicking over

[vRSG60]

Well to their credit AF Rayspeed have responded asking me to either get the engine or scooter to them and they'll take a look at it. The engine, however, has been stripped and the big end bearing has disintegrated. I'm going to scource a new crankshaft assembly and get that fitted.

http://www.scooterrestorations.com/lamb ... d-bearing/

This any good?

Or this any better?

http://beedspeed.com/lambretta-crank-cr ... -1145.html

[Argentopercarter]

[quote="vRSG60"]Well to their credit AF Rayspeed have responded asking me to either get the engine or scooter to them and they'll take a look at it. The engine, however, has been stripped and the big end bearing has disintegrated. I'm going to scource a new crankshaft assembly and get that fitted.

http://www.scooterrestorations.com/lamb ... d-bearing/

This any good?

I took delivery of one of these today. Webs and rod are scruffy but the main problem is that the drive side splines are very poorly machined. The surface of several appear to be breaking up and I picked slivers of metal out from between them with my thumb nail.

Viewed through an 8 x lupe - not a pretty sight.

It is going back.

[storkfoot]

I'm reading between the lines that this is one of the Indian restored GPs that AF sell. As such, you may find that you have an Indian GP 200 crank. If this is the case, and as you have already been advised, you should (unless you really do have catastrophic crank failure) use these webs and get a decent 110mm conrod fitted with a good quality big end bearing. By decent, I mean Yamaha or Kawasaki, for example.

[vRSG60]

I'm reading between the lines that this is one of the Indian restored GPs that AF sell. As such, you may find that you have an Indian GP 200 crank. If this is the case, and as you have already been advised, you should (unless you really do have catastrophic crank failure) use these webs and get a decent 110mm conrod fitted with a good quality big end bearing. By decent, I mean Yamaha or Kawasaki, for example.

Exactly what I have yes. The mechanic dealing with it suggested a full crank assembly as maybe a cheaper option to renovating the conrod ???

[gaz_powell]

My first choice would be SIL webs with decent rod/bearing - yamaha or rb but that does involve a time factor.

Having just read the thread on the pm crank failure go the above route and forget tameni

Shame as the old MEC cranks were decent quality and price.

Good luck

Gaz

[storkfoot]

Last crank I had built at Grampian cost me about £50 for an old Indian GP 200 crank and then another £50 for the Yamaha Conrod and fitting. That was only a couple of years ago.

[vRSG60]

Pictures of the crank for those that are interested -

[diesel]

Can the mechanics amongst us tell by looking at those photos whether or not the big end was adequately lubricated?

[Adam_Winstone]

I've seen so many of the standard SIL big end bearings break up or be that nasty dull grey that poor quality bearings go just before they break up, that I don't think that poor lubrication is the cause in most SIL crank failure cases. In the 80s/90s at least one dealer used to strip out and replace all of the factory cranks on the new SIL GP200s that he used to sell, simply because the rate of warranty failures didn't make economic sense, let alone the bad reputation that goes hand in hand with such failures.

The most I've known out of a standard SIL GP200 crank is 6000 miles and the crank on that had a nasty dull grey bearing when inspected and wouldn't have lasted long. If you manage to get more then this out of a standard SIL crank (not the SR uprated bearing item) then I'd suggest you're probably not riding it hard enough! (lol)

Adam

PS - Don't bin that crank though because SIL webs make for excellent cranks when fitted with a decent replacement bearing and rod (towards the top of the crank tree).

[vRSG60]

Can the mechanics amongst us tell by looking at those photos whether or not the big end was adequately lubricated?

Something I thought but the engine would also signs of lack of lubrication too. They share the same oil/petrol mix.

I'm with Adam, poor bearings.