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Suffolk Colt/Super Punch 25A motor torque settings

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goodgrass Sun, 07/08/2016

Is there a workshop torque setting table/chart guide for the above motor?

I know the head is 12.5 ft lbs and the flywheel is 28 ft lbs I think, but what about the rest such as the big end, magneto end plate, sump, etc ?

 

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wristpin Sun, 07/08/2016

Suffolk cast iron block 75 and 98 cc engines.

Points .018" *

Inlet valve .007"

Exhaust .015"

Plug gap .025"

Timing 22 - 24 degrees btdc

Head bolts 180" lb

Big end  bolts 130" lb

Flywheel 22' lb

* very early engines with "see saw " points .020"

Never seen a torque specified for the block to sump bolts  but I have seen the threaded boss pulled out of the sump !

 

goodgrass Mon, 08/08/2016

Thank you for that useful information.

I haven't a specification in inch pounds for a long time.

What do you think the estimated torque spec for the sump and magneto back plate bolts would be?

I would be quite easy to over tighten the sump bolts.

wristpin Mon, 08/08/2016

No official info for the mag back plate but the figure for the crankcase cover on th A98 and A114 alloy blocks is 100 " lb  . As for the sump I would say just pinch them up tight with a short spanner and check them when it's run a while.

goodgrass Mon, 08/08/2016

Thanks for that, I will follow your advice.

I have a useful Haynes manual which covers this mower and engine, but the important information you have provided me is sadly omitted.

goodgrass Fri, 12/08/2016

I have often seen inlet 4 thou and exhaust at 10 thou quoted - is that incorrect?

wristpin Fri, 12/08/2016

I have often seen inlet 4 thou and exhaust at 10 thou quoted - is that incorrect?

I've never seen those settings for the cast iron block engines, only ever seen 7 and 15. 

For the A98, 9 and 11 and for the A114, 6 and 10.