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Discussion Starter · #1 ·
Hey all! New to the forum. I’ve got two 1970 Suzuki T350’s, one of them is fully functional and the other is a parts bike. I’d like to get the parts T350 back on the road with a twist! Its engine is too far gone to fix. So here’s my plan on getting it road worthy again.

I have REALLY wanted to have a offbrand Harley and put a V-twin Kohler Command 20 on that frame. Of course make it durable at high rpm (billet con rod, piston, stiffer valve springs, mikuni carb, etc). I have a command 20 in my possession and it will fit on the frame with some modifications. One downside: what about a transmission for it?

Ideally, I’d need a transmission with an input sprocket with a chain going to the engine’s crankshaft, and an output sprocket with a chain going to the rear wheel. (Will have to stretch the frame for it to work.) I have done hours of research on motorcycle/dirt bike/atv transmissions, and no one makes a stand-alone transmission that’s not directly paired to an engine except for Harley-Davidson. (WAY out of my price range!) The other option would be a CVT transmission. It’s relatively cheap but not practical for a motorcycle, mostly because I’d want it to cruise around 60 mph. And not screaming at 7,000 RPM either.

I’ve seen 2 youtube videos of people converting an atv engine into a solo transmission. They had a input shaft machined in place of the crankshaft, removed the top end, and made covers to go on the crankcase and the mount for the cylinder. It’s possible for me to do that, but it’s critical that the transmission has its own fluid, since most engines have the same oil for both the engine and transmission.

If there’s no way possible I could rig a gearbox with a clutch to it, guess I’ll go with the CVT transmission. I could put a small sprocket on the rear wheel and a bigger sprocket on the driven clutch so it’ll have a higher top speed, but it’d burn belts up quickly trying to get up to speed.

Most of you must be thinking, “Why not buy a cheap Lifan engine?” I’m completely bound and determined to get that V-twin to work one way or another. It’d be a conversation starter and a one of a kind! It would be a lot of work, and I don’t plan on spending a lot of money on it. Any advice or info would be greatly appreciated on anything I’ve included in this post.
 

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Sounds very agricultural. Two downsides to your engine choice, no transmission and it has an anti-vibration counter-balancer in it that will explode if you try to turn it into a performance engine. You might better put a little diesel engine in it and forget about trying to make it go fast, it never will.
 

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Discussion Starter · #3 ·
Sounds very agricultural. Two downsides to your engine choice, no transmission and it has an anti-vibration counter-balancer in it that will explode if you try to turn it into a performance engine. You might better put a little diesel engine in it and forget about trying to make it go fast, it never will.
Sounds very agricultural. Two downsides to your engine choice, no transmission and it has an anti-vibration counter-balancer in it that will explode if you try to turn it into a performance engine. You might better put a little diesel engine in it and forget about trying to make it go fast, it never will.
Midwest Super Cub has several performance parts for Command Series V-twins. A completely built performance Kohler with their parts can hit 12,000 RPM and around 100 hp on the dyno. Several youtubers have built Kohler V twins and Predator 670s for go karts and are very stout.
 

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I too have my doubts on that. Nothing to double or even triple the power and easy but 5X is stretching it.

The CVT idea is dead on arrival, I built some industrial CVT and you don't 'slip the belt', they never slip, only appear to. You must have a way to adjust it on the fly.

Another one biting off more than one can chew, ANYTHING is possible if enough money is thrown at it but is the end result worth it? Would be wrecking some rare parts, those just don't grow on trees.
 

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Put an electric motor into it using the T350 chassis clutch and transmission and with enough batteries he might have something there.
Something very heavy and with antiquated brakes and suspension handling.

Put the hopped up V-twin engine into a home built kneeler sidecar chassis, that would be cool and maybe work.
 

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Discussion Starter · #8 · (Edited)
Put an electric motor into it using the T350 chassis clutch and transmission and with enough batteries he might have something there.
Something very heavy and with antiquated brakes and suspension handling.

Put the hopped up V-twin engine into a home built kneeler sidecar chassis, that would be cool and maybe work.
See, that’s exactly why I went and asked people who have a lot more experience than I do. We all started somewhere, right? And planned out something we thought was amazing but ended up being a stupid idea? That’s me, fo sure.

I wouldn’t commit a mortal sin and destroy a hard to find motorcycle now, would I? That thing was sitting out in the weather for 40 years! Only reason I bought it is it only had 750 miles on the engine since the original owner parked it in 1973 after the clutch failed on it. Both rims are riddled with rust holes, luckily my dad has 2 good rims off of a GS450 that fit and has disc brakes 😁 The battery side cover is gone, oil tank cap was off and rusted through the bottom of the oil tank, and so on blah blah blah. I could give every reason why it would be impossible to restore it back to original condition, I could hand you 4 full pages of inexpensive solutions for substituting parts that are missing, but why keep talking about it? I know its because I’m young and stupid. Maybe, just maybe, I’ll look into your electric motor idea when I get another stimulus check.

I’d rather have it back on the road Frankenstein’ed together than let it rot away. That’s just my opinion, to each his own. Oh and by the way, at the bottom I put a link to a 100hp kohler v-twin at 12k rpm if you just so happened to think it was possible. May cost a ton of money to build one, but here in my town they have garden pulling tractor competitions with IH cub cadets running all season long with a command v twin; the only performance mods were billet rod & piston, heavy valve springs and carb rejetted.
 

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Nice velocity stack.

... but that guy is measuring horsepower at the crank and not off a rear wheel, that's a great way to yield really impressive numbers. Plus his little dyno was not up to the task, it was very obviously posting inflated numbers all over the place relative to his engine revs.

I bet it cuts grass pretty fast though.
 

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Discussion Starter · #10 ·
Nice velocity stack.

... but that guy is measuring horsepower at the crank and not off a rear wheel, that's a great way to yield really impressive numbers. Plus his little dyno was not up to the task, it was very obviously posting inflated numbers all over the place relative to his engine revs.

I bet it cuts grass pretty fast though.
Might just rig a PTO shaft and a 3 point hitch to it. May come in hand who knows
 

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The torque meter used in software in the video is worthless, it in no way approaches reality at all. Making more torque at some points than engines 3X the size. It lags as well by some 4000 rpm in places too and watch torque triple when the engine drops back to half speed or less. A comedy. And nice velocity stack indeed, that and carb to make a 12-14 inch straight shot to ram directly into intake manifold wall at a ninety degree angle. The person who designed that intake was not very knowledgeable, you don't straighten out air just to then ram it nice and straight into a brick wall.
 

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I get it. The torque meter is tied to the engine brake. Step/pause through the engine rpm decel and it becomes crystal clear the motor there is out of breath past about 8000 rpm, the hp. then quits rising other than with massive overrun which fakes you out, you will not be making much more power past that 8000ish speed. Just because an engine will get up that high in no way tells you you can use it there.
 
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