YUKONFLYR

Curious as to the age or year of this SJ46. Picked it up as a "Previously Owned"
and in real good shape.

Thanks

bob27s

My Feedback: (19)

The carb is probably most telling.

Note the carb inlet does not have a "venturi" ring above the body. Also, there is a wire-adjustable low-speed needle. Those were only on the very first sport jett engines.

Red spinner nuts and red drive washer was standard on the original engines. Phased out fairly quickly. Looks like one of the red nuts though.

It is one of the block-2 crankcases with the Jett logo cast in (1993-1998). Current cases have the "belly band" cast in under the crankcase.

Just from that, figure it is 1993/94 vintage.

Just as a caution .... none of the current inside parts fit the old crankcase.

Also, look on the case for markings. Dub always engraved his name and a number or the date into the engine when it was built. If not there, the crankcase was replaced along the way.

Bob

YUKONFLYR

Thank you Bob for the very detailed answer.

Everything works great on the engine. Only one minor leak at the base of the fuel nipple
where it screws into the carb.

Can parts still be had for this engine? Not that it needs any...
Just thinking about the future.

Thanks

bob27s

My Feedback: (19)

key parts like piston ,sleeve, head button and rod are no longer available. They are different now for the current crankcase.

I thinkkkk the crankshaft is the same.

Carb is similar

YUKONFLYR

No markings on the case so that must have been replaced as well.

Engine still has some pinch left in the sleeve when I disassembled it to take a look.
dub sent me a reg backplate to loose the backplate mount and a new spinner works just fine.

This engine has the racing engine bolt pattern ( same as a nelson q40 ) unlike the current sport jetts, so it must be from
racing stock, Sure screams when I ran it the other night.

Do sport jetts ever wear out? I have seen lots of posts as to the inability to wear one out, just wondering.

Thanks again Bob for the info, its appreciated

bob27s

My Feedback: (19)

Usually they won't wear out - takes some human intervention like a handful of lean runs or a spoon full of dirt in the carb .

My oldest SJ-46 runs very well. Its probably about 200-300 rpm down from when it was a year old....... but it has run just like that ever since no better, no worse. So I consider that "normal"

The very early crankcases were all drilled with the ST X-40/nelson/jett racing mounting holes. All of the jett cases were the same for a while. Evenutally Dub changed the sport engines to match the OS mounting standards.