Starter motor bolts.

[Johnny P]

Hello everyone.

I have a 284 Jinma with Y385 engine. Can anyone tell me the bolt thread size of the bolts that hold the starter motor on to the flywheel housing.

Thanks

Johnny P

 

[piper184]

The online catalogs show M10 X 34 with a 10 X 140HV washer

 

[Johnny P]

The online catalogs show M10 X 34 with a 10 X 140HV washer

Thanks piper 184. Excuse my ignorance re these bolts. Do I take it that 34 refers to the length. My bolt looks like the thread is 1.25. So I think it is a M10 x 1.25. Does a standard M10 bolt have the same thread size.

 

[piper184]

In this case the thread pitch is not specified. The 34 refers to the length as measured from underneath the bolt head to the end of the bolt.

For metric threads the pitch is the measured distance from the top of one thread to the top of the next, expressed in millimeters.

Generally when threading cast iron a coarse pitch is used because it gives more strength to the threads but fine pitch is used where you need to apply more torque to the threads.

For an M10 bolt 1.25 pitch is considered fine and 1.50 is considered coarse.

Here is a table that shows some of the common metric bolt sizes and thread pitches. It was literally the first link that came up in my search engine.

Bolt Depot - Metric Thread Pitch Table

www.boltdepot.com

Then of course one has to consider the strength of the bolt. This is the number on the top of the head. Typically 8.8, 10.8 or some such number. The higher the number the stronger the bolt. 8.8 is usually the lowest number you will see and is probably just fine for holding the starter to the engine.