Engine Rebuild

[Doss1961]

I'm about to start my rebuild of my T250 engine and I'm wondering if anyone knows the torque settings and sequence for the top and bottom engine casings.

Thanks
Paul

[dollydog]

hi paul, there should be numbers cast into the crankcases which shows you the sequence to undo and redo all the bolts. i always take the top 4 bolts out last and replace them first. but be careful with all the m6 bolts as they are very easy to shear - they are getting on 50 years old don't forget. i always replace them with new stainless hex head bolts and copper grease them. can't find the torque settings at the mo, but it's pretty low if i find it, i'll post it up. if you can't find the numbers, they are just undone in as diagonal a sequence as you can manage, like top right, bottom left etc.
cheers, dd.

[Craig380]

As Dolly says, the bolt holes have numbers near them to indicate the sequence. Suzuki's recommended specs for the crankcase bolts (which should all have the letter S on their heads) are:

6mm bolts: 5 to 7 lb-ft
8mm bolts: 10 to 17 lb-ft
10mm bolts: 18 to 29 lb-ft

(the measurement indicates the shank diameter, not the bolt head size)

[jabcb]

The T250/T350 was based on the T305, which was based on the T20.
The T250/T350 shop manual is pretty skimpy on info. Some additional info is in the T305 manual & T20 manual.

The T500 crankcase bolt tightening order is on page 45 of the T500 shop manual.
I think later T500s have an additional bolt, so this isn’t exactly correct for the later motors.
The T500 bolt order should be a pretty good guide for your T250.

Shop manuals are here: https://www.oldjapanesebikes.com/mraxl_ ... /index.php