Identifying a SP engine on a J1 / J2

[Mori Man]

It doesn't take much to make a regular model look like a SP , single seat cowl, splash of paint and some decals will soon have it looking like one.

The easiest being calling it a J1 as most of the road parts were the same between it and the H1 , however the J1 does have an SP engine and that has slotted cams inside with close ratio box but doesn't have the back torque limiter clutch. This can be a bit hard to check when your looking over a potential SP purchase but one sure fire way is to check the block and see if it has been stamped ( Granted after this post some dodgy bugger might attempt to replicate ) - look at the font & size on these photos and note it has only been struck once even if the indent wasn't perfect.

IMG_5868g.jpg

Another on my F3 engine

IMG_5867f.jpg

They also look to be stamped in the exact same spot - will need to measure that to confirm.

If you find this mark and want peace of mind at time of purchase have the seller sign a declaration of sale that the bike is known to him as an SP with genuine engine - was you open it up to see the cam's and discover it's not you can have them for fraud.

SP cams from an M will not fit (well they do but the motor wont turn over with out locking ) directly , to fit M cams you need J sprockets and these are finished.

I have a few more SP engines kicking about so when I un-earth them will check for marking as two are M so want to see if they stamped them the same way.

[v1nn13]

Excellent thread, this is what i wanted to know =]. This might be me sounding like an idiot but, do you have pictures of the cams on the j1 engine?

[zxdillan]

hi mori-man
i have recently got hold of an bike which i am in the process of rebuilding. after typing the frame number into a kawasaki site the model comes up as j1.
having checked the engine there is no letter j, but stamped perfectly vertically on the head and barrels is GBR. just wondered if this could have been built by japan as a racing engine for uk export. engine has been skimmed, polished and ported, adjustable sp cams, balanced and knifedged crank. just wondered if you could shed any light. thanks.

[Mori Man]

hi mori-man
i have recently got hold of an bike which i am in the process of rebuilding. after typing the frame number into a kawasaki site the model comes up as j1.
having checked the engine there is no letter j, but stamped perfectly vertically on the head and barrels is GBR. just wondered if this could have been built by japan as a racing engine for uk export. engine has been skimmed, polished and ported, adjustable sp cams, balanced and knifedged crank. just wondered if you could shed any light. thanks.

I would hazard a guess that was the tuner who stamped it. The H & J were never an official UK bike.

Now in process of building my M1 and it has a M stamped just like the J models - so I believe all genuine SP engines should be like this.




Again it's easy enough to fit cams , gearbox and clutch from SP editions , the J stuff is now finished but you can still buy M parts new.