I've owned probably 30 outboards, dozens of chainsaws, string trimmers, and dirt bikes, so I'm no stranger to 2-strokes. I've just never modified them and have little experience with some of the finer points.
In particular, I'm considering changing the orientation of a 2-stroke from vertical to horizontal by laying it on its side. It's a single carb, so I could fab up a spacer that clocks the carb 90 degrees... but is that it? I would assume that there is alwasy some fuel puddling in a 2-stroke crankcase. Does changing the orientation cause anything I'm not thinking about? cylinder washing on one side? Inertial changes to intake charge by changing its direction? (like changing from a tunnel ram to a low-rise on a V8)
Is it really just as simple as laying it over and clocking the carb?
Unfortunately my example is a 30hp outboard engine, so I know that clocking the carb isn't a simple thing. The linkages are whacko on those things. The throttle opens when the magneto baseplate rotates to advance the timing, so some real fab will need to go into it.
I think an outboard would be about the easiest since your exhaust is compact and all coming into a single outlet that is tight to the motor.
I don't think I'd loose much sleep over the oiling thing. Most of the fuel and oil is suspended in the air and momentum will take it where it needs to go.
The real question is what car are you putting it in?
I really know very little about outboards, but came up on two strokes. YZs, RDs, and RZs specifically.
Carb tuning and expansion chambers were cheap, easy, and large bumps in oomph (may have felt like bigger bumps than they actually were). The RD 350 I had was interesting. The PO raced it, and had shaved the heads. To get the compression ratio back under control, under the instruction of my boss/friend/racer/Viet Nam vet mentor, I spaced the whole jugs up with two stacked gaskets between them and the crank case. This changed the timing a bit, making a stronger, later rpm powerband. The wellies were epic, and to a 22 year old me, it felt really fast.
Unfortunately, absolutely none of this is necessarily helpful to your situation, but I was compelled to share. FWIW, I think your crank will stay lubed from the premix regardless of orientation, too. One way to find out. (Ninja edit-poor spelling)
mke
Dork
3/19/22 9:01 a.m.
wheelsmithy (Joe-with-an-L) said:
FWIW, I thing your crank will stay lubed from the premix regardless of orientation, too. One way to find out.
that sounds right....there is a reason chainsaws and weedwackers are 2 stroke, they run fine in any orientation. Rotating it would concern me at all
1SlowVW said:
The real question is what car are you putting it in?
Not a car. Converting an 8' tri-hull rowboat to a jet. I have a 3.5hp and a 6hp outboard, but this river is a never ending flow of shallow rocks. Some people cage their props and promptly rip off their lower units. Others use a jet drive on the lower unit which still has cast aluminum below the hull and they're terribly inefficient. In order to plane I would need a 20hp outboard head which would likely sink the boat. I'm thinking if I had a 15hp OMC head directly to a jet I'd be set. I also have two 30-hp OMC heads that I could scavenge but I'll have to look at power/weight benefits.
There's a thread here... lemme find it.
I thought about a Gy6, but the cast-in CVT would be a problem... as would the 12,000 rpms. Plus I can only get about 12hp after spending a lot of money.
Not looking to make a performance thing, I just want to get on the river and fish/putz around and be able to go fast enough so that going upstream won't require packing two meals. I'm shooting for 10-15 mph.
1SlowVW
HalfDork
3/19/22 11:38 a.m.
Curtis73 (Forum Supporter) said:
Speaking of boats following me home...| Off-Topic Discussion forum | (grassrootsmotorsports.com)
Huh, I tried my hardest to derail that thread. So I guess all I will say here is that a small jet pump mounted to a 15 that's slung low in the hull should work just fine.
I had an old two-stroke enduro that had a quart-ish of oil in the crankcase. It would make a mess if the bike laid over for too long.
As far as mods go, exhaust is the big hitter. That flying car guy, (Mosler?) invented the Supertrap muffler to make snowmobile engines fly.
mke said:
wheelsmithy (Joe-with-an-L) said:
FWIW, I thing your crank will stay lubed from the premix regardless of orientation, too. One way to find out.
that sounds right....there is a reason chainsaws and weedwackers are 2 stroke, they run fine in any orientation. Rotating it would concern me at all
I hope it will too, but I also know that chainsaws, weedwackers, and other 2-strokes spend 90% of their time upright. I was concerned that running it constantly in a position it wasn't designed for might change the physics of how the atomized fuel/oil actually flowed past the bearings.
1SlowVW said:
Curtis73 (Forum Supporter) said:
Speaking of boats following me home...| Off-Topic Discussion forum | (grassrootsmotorsports.com)
Huh, I tried my hardest to derail that thread. So I guess all I will say here is that a small jet pump mounted to a 15 that's slung low in the hull should work just fine.
I didn't see it that way. Besides, you didn't 
