worn or damaged vespa px crank sealing pad !!

[wink]

Hi all,

Can anyone tell me how to test (without splitting the cases) a fully built P200 engine to see if the sealing pad on the crank is damaged or worn and how would the engine run if it was worn.

I have an old rebuilt lump that I'm thinking of using on a project and I seem to remember it didn't run too great and the sealing pad did look a little worn when it was being built. So I was just wondering if this was the reason why it ran so poorly.

Cheers Chris

[roadrunnerian]

Hi m8 to test the sealing pad seal you have to remove carb and pour petrol into the inlet till level then time how long it takes to clear away anything under 20 seconds its knackered you will have to reedvalve it or repair the casing weld or metal putty. anything over 50 seconds its as good as new.good luck m8

[shamrockexpress]

Hi m8 to test the sealing pad seal you have to remove carb and pour petrol into the inlet till level then time how long it takes to clear away anything under 20 seconds its knackered you will have to reedvalve it or repair the casing weld or metal putty. anything over 50 seconds its as good as new.good luck m8

Is that test method not suppose to be done using 2 stroke oil????

[roadrunnerian]

i think you are right shamrock express m8 my mistake put it down to age

[wink]

Hi, thanks for the repsonses. I checked it las night by topping up the inlet valve with 2 Stroke and it took over 25 minutes to clear down, so I think the sealing pad should be ok.

Out of interest, does anyone know what impact a damaged pad would have on the performance and running condition of an engine, would it run, or just run really badly?

Cheers Again, Chris

[jonny snatchsniffer]

you would be surprised at how many seemingly fine running motors ive seen with a couple of 1mm scores accross the pad and some very bad ones only had idle problems, at 6000 rpm the fuel doesnt have time to just sit there when the crank is spinning 100 times a second, the exhaust will pull the mixture in too
could be loads of reasons why it ran poorly

[goldeneye]

just doing a malossi 166 motor,old mk1 px casings, and after attacking the transfers, turned my attention to the inlet. some quite heavy score marks on the sealing pad, but most came out after widening and flowing the inlet. thing is, this motor ran no problem (standard 150) before, lad used it every day for work, saying it only took a couple of kicks to get going in the morning. its when they have had real damage, like a broken ring, or a stray circlip going round the crank, or, common on T5"s, the carb tickover spring going down the inlet and buggering everything.

[shamrockexpress]

just doing a malossi 166 motor,old mk1 px casings, and after attacking the transfers, turned my attention to the inlet. some quite heavy score marks on the sealing pad, but most came out after widening and flowing the inlet. thing is, this motor ran no problem (standard 150) before, lad used it every day for work, saying it only took a couple of kicks to get going in the morning. its when they have had real damage, like a broken ring, or a stray circlip going round the crank, or, common on T5"s, the carb tickover spring going down the inlet and buggering everything.

Done that to a mates brand new T5 in the 80s OUCH!!! well i was only trying to turn the tick over up!!! didnt know it was differnet to my PX.........WE found out the hard way!!!!!!