Kubota Superdream Honda MK5 and MK4

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Blunt Eversmoke
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Re: Kubota Superdream Honda MK5 and MK4

Post by Blunt Eversmoke » Fri Feb 21, 2014 10:37 pm

Tim wrote:Thanks both for the feedback I really appreciate it , and if you hadn't mentioned " an organic look" I wouldn't have thought of using of wood . I could investigate forming a acrylic transparent cover but I'm not a big fan of plastics. I guess if other persons want one it might be worth it . Also I am not sure if it would fit in the vacuum forming machine!
Cheers Tim

Disclaimer
Please note the bling blue lights on the radiator coollng fans are not by design, I forgot to remove them from the fans before fitting them and now I have to drain and remove the radiator to get to them.
Hehehe, when I said "organic" I meant that it looks like the CVT really belonged there stock out of the box, not "organic" in the earthy-crunchy sense :D . Still, the wood is as rat bike Keep It Simple Stupid as it gets, love that :)

If you don't like plastics, you'll have to come up with some tin contraption, only don't just take a tin pot and call it a day - as nice as it worked on some other CVT bikes here, on yours it will look out of place, you'll have to keep the front pulley cover as close to form as possible, maybe by hammering multiple concentric tin rings in form and riveting or welding them together? Bad luck you can't just keep it naked :D

pietenpol2002
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Re: Kubota Superdream Honda MK5 and MK4

Post by pietenpol2002 » Sat Feb 22, 2014 1:48 pm

Tim, since your rear pulley cover allows for exposure to the elements, I presume a front cover could do the same. I''ve got several of the guards as shown in the pics below that I'm considering for my primary drive. Just another option to consider. They're CVT guards from Yamaha and Suzuki ATVs and both were sold in the UK. You'd still need to forego the bell-bottoms from your wardrobe.
CVT Guard 2.jpg
CVT Guard 1.jpg
Ron
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gilburton
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Re: Kubota Superdream Honda MK5 and MK4

Post by gilburton » Sat Feb 22, 2014 3:02 pm

The belt will need some form of cover against the rain or it will slip. Also general road debris thrown up by the front wheel.
We do sometimes get rain over here :lol:

Tim
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Re: Kubota Superdream Honda MK5 and MK4

Post by Tim » Sat Mar 01, 2014 6:00 pm

Blunt Eversmoke wrote:
Tim wrote:Thanks both for the feedback I really appreciate it , and if you hadn't mentioned " an organic look" I wouldn't have thought of using of wood . I could investigate forming a acrylic transparent cover but I'm not a big fan of plastics. I guess if other persons want one it might be worth it . Also I am not sure if it would fit in the vacuum forming machine!
Cheers Tim

Disclaimer
Please note the bling blue lights on the radiator coollng fans are not by design, I forgot to remove them from the fans before fitting them and now I have to drain and remove the radiator to get to them.
Hehehe, when I said "organic" I meant that it looks like the CVT really belonged there stock out of the box, not "organic" in the earthy-crunchy sense :D . Still, the wood is as rat bike Keep It Simple Stupid as it gets, love that :)

If you don't like plastics, you'll have to come up with some tin contraption, only don't just take a tin pot and call it a day - as nice as it worked on some other CVT bikes here, on yours it will look out of place, you'll have to keep the front pulley cover as close to form as possible, maybe by hammering multiple concentric tin rings in form and riveting or welding them together? Bad luck you can't just keep it naked :D
Hi
Hey watch out for a crunchy feel , I may be tempted to weave a willow cover to get that Somerset levels organic feel!
I don't think I could make a success of a tin cover , compound curves look rubbish unless they are perfect , to do that you really need and English Wheel type roller , outside my budget . I am toying with the idea making a former and die out of wood and attempt to form heated acrylic or styrene sheet in it . Or may be a willow cover"......."?

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Re: Kubota Superdream Honda MK5 and MK4

Post by Tim » Sat Mar 01, 2014 6:06 pm

pietenpol2002 wrote:Tim, since your rear pulley cover allows for exposure to the elements, I presume a front cover could do the same. I''ve got several of the guards as shown in the pics below that I'm considering for my primary drive. Just another option to consider. They're CVT guards from Yamaha and Suzuki ATVs and both were sold in the UK. You'd still need to forego the bell-bottoms from your wardrobe.
CVT Guard 2.jpg
CVT Guard 1.jpg
Hi
It's a shame your across the pond as they look interesting what diameter pulley will it fit around?

I will look into the guarding when the build has progressed further as I can't yet work or see what's going to be possible and look good so I may be back to you.

Cheers Tim

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Re: Kubota Superdream Honda MK5 and MK4

Post by Tim » Sat Mar 01, 2014 6:37 pm

So the maiden voyage of the turbo mk4 was interesting , the handling was appalling but I found front tyre pressure at 10 psi and the top yoke nuts were loose. The turbo makes a wonderful wheezing noise when it starts to spool up but I didn't push it very hard as there were lots of hot smells and smoke from oil burning off which resulted it me being a bit cautious. On return after 2miles I noticed the lovely sparkly blue fans had both sheared off and cartwheeled into the radiator . The mounts are not sufficient and are allowing the fans to vibrate into the radiator under full tilt .Back to the drawing board and wait for new set of fans.
image.jpg

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coachgeo
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Re: Kubota Superdream Honda MK5 and MK4

Post by coachgeo » Sat Mar 01, 2014 6:44 pm

Tim wrote:So the maiden voyage of the turbo mk4 was interesting , the handling was appalling but I found front tyre pressure at 10 psi and the top yoke nuts were loose. The turbo makes a wonderful wheezing noise when it starts to spool up but I didn't push it very hard as there were lots of hot smells and smoke from oil burning off which resulted it me being a bit cautious. On return after 2miles I noticed the lovely sparkly blue fans had both sheared off and cartwheeled into the radiator . The mounts are not sufficient and are allowing the fans to vibrate into the radiator under full tilt .Back to the drawing board and wait for new set of fans.
image.jpg
If there is room maybe suction fans on other side of radiator are better than pusher fans. That way wind of cruise speed bends blade away from radiator? Also you could potentially at cruise speeds where fans are not needed have them act as generators to charge batteries or run extra driving or marker lights etc?

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Re: Kubota Superdream Honda MK5 and MK4

Post by alexanderfoti » Sat Mar 01, 2014 11:13 pm

Also have a look at second hand rad fans from 125 motorbikes. They are pretty tough and last much longer than computer fans. I have also broken mine with a computer fan, the vibrations broke the center off.

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Re: Kubota Superdream Honda MK5 and MK4

Post by Tim » Sun Mar 02, 2014 3:42 pm

alexanderfoti wrote:Also have a look at second hand rad fans from 125 motorbikes. They are pretty tough and last much longer than computer fans. I have also broken mine with a computer fan, the vibrations broke the center off.
Hi Alex
I was lazy and only mounted the on two for the four mounts and the radiator was only top hung . I reckon your right but now I've engineered them for 140 mm fans I will see how long they last now and if they fail its 125 fans for me!

Cheers Tim

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Re: Kubota Superdream Honda MK5 and MK4

Post by Tim » Sun Mar 02, 2014 3:46 pm

coachgeo wrote:
Tim wrote:So the maiden voyage of the turbo mk4 was interesting , the handling was appalling but I found front tyre pressure at 10 psi and the top yoke nuts were loose. The turbo makes a wonderful wheezing noise when it starts to spool up but I didn't push it very hard as there were lots of hot smells and smoke from oil burning off which resulted it me being a bit cautious. On return after 2miles I noticed the lovely sparkly blue fans had both sheared off and cartwheeled into the radiator . The mounts are not sufficient and are allowing the fans to vibrate into the radiator under full tilt .Back to the drawing board and wait for new set of fans.
The attachment image.jpg is no longer available
If there is room maybe suction fans on other side of radiator are better than pusher fans. That way wind of cruise speed bends blade away from radiator? Also you could potentially at cruise speeds where fans are not needed have them act as generators to charge batteries or run extra driving or marker lights etc?

The fans are behind the radiator and pull the air through, they run continuously and this is only because the alternator could power a small ship. :)

So the weather has been kinder and I ventured out for a test run , I haven't increased the fuel to the engine as yet however there is a noticeable increase in performance on hill climbing ability compared to the non turbo bike. The bike does seem to excellerate more swiftly , but you know this could just be wishful thinking evoked by the wine from the turbo as it spools up to speed !
The turbos does take a couple of second to spool up (reach operating speed , it only works when the engine has to work hard) it works really well a cvt transmission but the lag could be a potential pain with a manual gearbox arrangement .

Anyway a couple of miles later and the final drive belt snapped. Research indicated this was due to being used with insufficient tension . This evidently results in the teeth riding over the pulley which then peels the tooth at the root. This then overloads the next tooth so on and on and ultimately brakes the belt . I had noticed the drive surging under hard acceleration and assumed it to be the cvt . So new belt on and much increased tension should be the cure .

With out thinking I removed the rear wheel to fit the belt and then worked out you only needed to remove the suspension unit and then slip the belt over the pulley. It takes about 20 minutes to fit and then around 10 minutes to re tension and check its running in the centre of the pulleys .
image.jpg
Broken drive belt at 30 miles
image.jpg
Research indicates the peeled teeth are due to under tension of the belt

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