252 engine

[wallis1924]

hi i was needing some advise on some problems iam haveing with a 252 jlo motor my dad got a unrestored snoscout snomobile wich has a 252 motor it was unsized but the bearings were done wich i replaced new gaskets and seals whene puting it together i had a hard time to put the seal on the flyweel side thier was some piting on the crankshaft i also replaced the points and condenser put it all together and i do have spark points are set about 14 thou rebilt the carb tilston 186a and then started to pull and pull and pull it would run fast for a few seconds then die tryed replaceing the carb even worse nothing i woundering if any one has had this problem before also if the crank is to pited could you put a speedy shaft over the pited area any help would be great

[Go Go Diablo]

Not sure about the JLO, but I have been able to put speedi-sleeves on Hirths when they are badly pitted as you mention.

Before:

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After

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[wallis1924]

thanks for the reply on the speedy sleeve info are the seals harder to get on with the sleve does it sound like the seals is leaking to you i havent run into this before i have also a hirth motor but i cant find the maker plate it was a retro fited to a 1968 ski doo 370 super it has a walbro carb on it could this be out of rouge dilablo thanks for the info

[Go Go Diablo]

The speedi sleeve is made of a very thin piece of expandable steel. It adds very little to the outside diameter of the shaft so the seals can be installed over them. I had no problem getting the seals over these speedi sleeve.

In regards to hearing the seal leak, I'm not sure that is possible. I install port blanks over the intake and exhaust ports of the motor and pressure test them for leaks. If the motor holds several pounds of pressure, I know the engine is sealed.

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This is a Hirth 54R motor used in the Diablo 500 and 502's.

[wallis1924]

good to know but how do you set this up block the intake and ex ports how much air do you pump in and hows the gage set up to no how much is in thier i might try to do this test my self

[wallis1924]

bruce can you tell me how you hocked up your gage to the engine

[Go Go Diablo]

This pump is a small hand pump like what is used on bicycle tires. I've made a connections with typical pipe fittings and a 1/4" hose hooked to the vacuum port on the motor. Does this 252 JLO have this vacuum port?

The steel port covers are available if you need them for $3 each. Have the spark plug install and tightened. With the port covers on and the spark plug in, the motor should be sealed tight.

I pump about 4 PSI into the motor and see if it holds air for a minute or two. If the motor has a leak, it either won't pump up or you pump it up and it bleeds right back out again.

Hope that helps.

Bruce