Honda 750 with Kubota Z482

[pietenpol2002]

I think it's time to go public with my current project. It's the same old CB750 that I had the Yanclone mounted in and originally coupled to a Comet 40 CVT. My obsession with thrashing gears compelled me to swap the CVT out for an Enfield 5 speed. And then I ran across a little Z482 locally some weeks ago that was just too good to pass up. So I pulled the Yanclone and built mounts for the Kubota. Engine and gearbox are mounted and blower mount is next. I've set a goal of having this on the road by May 1, 2014 and I asking you guys to hold me accountable to that goal. Also, many thanks to Russ (Mouse) for a wealth of information and encouragement.

Here are the details.
1. 1971 Honda CB750 donor stretched and hardtailed in the interest of making enough room for it all (with 7" seat springs to compensate)
2. Kubota Z482 twin
3. 2006 Royal Enfield 5 speed
4. Double sheave primary drive utilizing a banded and notched belt. Pulley on Enfield clutch is a 3 sheave 7.3L Ford diesel truck crank pulley.
5. Aisin AMR300 supercharger (with an intercooler held in reserve, but hopefully not needed as the plan is to not exceed 6 lbs of boost). Driven by 3rd sheave on clutch pulley
6. On-demand propane fumigation is built, but it remains to be seen if it will be used. The EGT should tell us if the little 482 can tolerate it
7. Kubota 14 amp dynamo. Lights are LED and swapped electric lift pump for a new mechanical one. Hoping to go the minimalist route since I have boxes of these dynamos.
8. Kubota radiator mounts behind the trans and blower
9. Stay tuned for the girder front end.

First pic is the Yanclone/CVT project.

And now the Kubota

Pardon the grungy blower. It's only for mockup and building mounts etc. To be replaced with one of the fresh ones.

Dynamo mounts aft as there's frame interference to the front.

[coachgeo]

Moving right along

[henneberg]

Hi,

Looking forward to see the process of your build.

[pietenpol2002]

Had the week off so I spent much of it in the shop. Amazing how long it takes to do the simplest things. I got the blower mount fabricated, but I now have to redo the pulley as I'm not happy with the how the pulley bush mounts up. And I can't weld the mount in place until I can align the pulleys. Stay tuned on that one.

Here's the dynamo mounted to the rear of the engine, It's actually mounted to the gearbox but the tensioner and steady are bolted to the frame. The gearbox is not adjustable, thus the need for the primary drive tensioner seen below that I fabbed. Both turned out quite well in terms of function.

[alexanderfoti]

Looking for excellent! Very similar to what I want do in the future, z482 belt drive in the place of my yanclones.

It's funny how you mention the little things taking so long. I spend about 3 weeks removing and reinserted the gearbox and realigning everything.

You say you have lots of those dynamos lying around? They are hard to find in the UK, so let me know if you like to sell me one

[pietenpol2002]

Unfortunate that you're not closer. There's a chap not far from my office who has a steady supply of low hour 482's that he sells for $400. He sold many for $300 until he realised what they're worth. And they come with alternator, radiator and electric lift pump. At one point he had 60 of them. Happy to send you a couple of the dynamos. I'll PM you.

[alexanderfoti]

Excellent! Ah that would be really good! There was one on ebay that went for £100 But I missed out! Much appreciated!


And that one was missing the flywheel and the manifolds. Thats a great deal!

[alexanderfoti]

In the UK these go for upwards of £800 quite frequently. I have though about buying an aixam microcar and nick all of the required bits from that.

[pietenpol2002]

Today's work would be titled "Pride Goeth Before the Fall".

There was no question that radiator was made to fit between those 2 tubes. Simply fab the mounts, weld them up, pop the rubber bushes in place and bolt her down. Room for the puke tank on top - life is good.

And then as I stepped back for the well-deserved 2-handed pat on the back, old Murph stepped from the shadows (c'mon, you all remember Murph. You know...................... the one from "Murphy's Law"). Seems to believe it's his mission to remind me of the little things I happen to overlook. Like the fact that this bike's a chain drive. The kind where there's a chain that goes from the gearbox to the rear wheel.

OK, now where's that drawing board???

[coachgeo]

hmmm........

Sprocket behind pulley


oooops

Had to scan thru your previous post images to see your ooops. See now your chain needs to run inside of that rear down tube thus one side of the radiator is in the way. Looks like a mistake I'de make too lol.

No room in front for the radiator? Granted then you have to add weight of a grill to protect the radiator.

[pietenpol2002]

And actually the sprocket you note Coach is the primary drive sprocket to which the pulley is welded. The final drive sprocket is even further inboard than that. Now that I've slept on it (and have my pride in check) I'll return to the drawing board and see what I can puzzle out. And indeed, it's probably headed out front where I then might not need the fan.

[pietenpol2002]

Once again, life is good. And Murph has receded back into the shadow. For the time being.

Cut away the mounting tabs and repositioned the radiator with new mounts to allow for the chain. Even with repositioning, it's still within the general framework of the bike and not dangling out there in the slipstream. Fabbed some mounts for the little thermostatically controlled fan. We'll see if it can keep things cool. The radiator's all rubber mounted to reduce vibration and room for the puke tank yet above the fan.

[coachgeo]

Nice craftsmanship!!! Hats off tooz ya.

[alexanderfoti]

Looking good!

[pietenpol2002]

Completed the plumbing to and from the supercharger while incorporating the original air cleaner. Got so cozy in there I ultimately resorted to a feeler gauge and KY jelly. The ducting from the blower to the engine can't even be seen tucked in behind the dynamo. A bit of cleanup and trimming still required on the clamps. BTW, anyone wish to speculate on whether you think this engine could be kick started?

[Mouse]

With hot glow plugs mine can be bump started with ease on the flat so I guess its all to do with weather your kick starter can get it over compression.

[pietenpol2002]

Good to know. Thanks!

[mark_in_manchester]

My ural-daihatsu is a kick start - you get one compression (330cc) per kick. Kick start lever is about twice as long as yours, and I have to jump my 13 stone onto it a little - but it works fine, even at 0 deg C.

cheers
Mark

[alexanderfoti]

Looking good!

[pietenpol2002]

Made a bit of progress on a few other items. Coolant and fuel system are all plumbed. Finished the primary drive cover, which was another case of scrapping the first effort on the aluminum pile. It just started to get so complex and unwieldy. And even when I switched to version below, one of the brackets took 6 hours and 3 tries. May yet drill a hole at the center of the blower pulley cover and also mount the crank driven tach drive to the primary cover - we'll see.

[albertaphil]

Loving the build Ron. I can wait to see how the blown z482 performs.

[pietenpol2002]

Completed the right side belt guards in aluminum. The Goldwing timing covers work great for that purpose. I only wish I didn't have to cover the belts with the bent up angles. Seems to distract from the covers. But then, pants legs and belts don't mix well at speed. I also bent up an aluminum mount for the intake on the left side of the bike. The intake for the air filter is aimed to the left so I just went on over to the left side to avoid both the ingestion of hot air from the radiator and the right side exhaust. Here's to hoping the supercharger compensates a bit for the miles of intake tubing.
Also rebuilt the seat spring mounts such that they now allow for a full 5 inches of travel.

[pietenpol2002]

Floorboards are mounted. Pegs are a bit restricting when my legs get stiff from being in one spot for so long. That, and the tendency to use what I've got lying about.

[pietenpol2002]

Exhaust is in place and probably one of the simplest and quickest projects thus far. It only required punching out a flange from flat stock and then one cut and weld of an old Triumph pipe. We'll see how noisy it is before deciding on a silencer.

[pietenpol2002]

Next step was to address the rear brake. My plan was for a convoluted system of pivots, through shafts, arms, stainless rods, springs, etc. etc. As I was about to wade into it last evening, my brother stopped by the shop, pointed to the cable system on the Savage and asked "Why not use that?". Always good to have that second head in the shop. And so I did. Still a few brackets to finish. But, it couldn't be better. Even has the bend at precisely the spot it's needed. Then pounded a pedal out of some aluminum flat stock. Great fun.

[Curtis in Texas]

Looking good. I always liked makingf the pedals and stuff on my builds.

[Stuart]

Impressive build there Ron

[pietenpol2002]

Build update - It's been nearly 2 months and I've succeeded in mounting the horn. As my father would say "You'll need to drive stakes to detect movement".

But, here's a question for the collective wisdom. In the pic below you can see the red arrow pointing to the fuel return fitting/hose from the injectors. Immediately to the right are 2 unused inlets to the water separator/fuel filter. The opposite side of the filter base has the same arrangement with the inlet being fed from the tank. Is there any reason I couldn't route the return line directly to the filter? My reasoning is that the return fuel would be entering the filter base under some amount of pressure whereas the fuel from the tank is only gravity fed. Would certainly save the work of routing it to the tank. Is there anything I'm not considering in this line of reasoning?

[albertaphil]

I thought your boti pumped the fuel through the filter?

If it does, then the pressure at your filter head will likely be higher than the return pressure. If it is not, then the only problem I can foresee is that the fuel that just circulates through your injection system and right back to the fuel filter will eventually get pretty hot.

I know others have gotten away with not having the fuel return routed to the tank, but last night I was out for a ride at about 15 degrees C, and after an hour I could really feel the heat with my knees In the 5L of fuel left in my tank. On a long trip, hot day, supercharged? I dunno... Best case I would say that you stand to sacrifice some power to hot fuel.

[pietenpol2002]

After a bit of further research I see what you're saying. The tank should gravity feed the low pressure pump which routes the fuel through the filters under pressure. And with my scheme the lift pump pressure would be competing with the return line at the filter. Makes sense too that returning to the tank would reduce the temp of the fuel supplied to the injectors. At least for a time. And to the extent the tank serves as a bit of a "radiator".
Confirms that initial fleeting thought "It can't be this simple".