XS750 to XS896 big bore

I'm thinking of increasing the capacity on my XS750
I guess you have read up on the options. Basically if you keep the 750 cylinders then you can only take it out to 825cc. To get it out to 896cc you need to have the XS850 cylinders.
Buy the pistons off Ebay out of Japan. The details are earlier in this post.
Once you have the pistons and possibly 850 cylinders it is an easy conversion, but you should think about an oil cooler.
Hopefully you can get it done quicker than I have!!! :)
 
Yes 825 would be fine.. I do need an oil cooler... though. Just want a little more grunt.. over the original but I have other projects so its taken a back seat.. hopefully get a ride out this weekend on the old girl.
 
Shed is finally finished, but I do need to organise it inside with some shelving.
Moved some items in.
IT200N which is the next project/restoration
13' Tango skiff which was an earlier project.
And I have just picked up a welding table/trolley, which I am sure will come in handy!! ;D
 

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The 2 items to finish before I strip it down to paint the frame, are the header (hopefully this Saturday) and the air filter. I want to try something other than pods! My idea is to make up a foam filter similar to the attached photo, but using a foam element rather than paper element.
The triumph flat slide Mikuni's have a OD @ 60mm inlet and standard tube is OD63mm. The 2 options are to slit the tube and reweld to 60mm or swage the tube down to 60mm and get a nice flare to weld into the airbox. I have a 20 tonne bottle press and some chrome moly bore pipe to make the swage tool.
The ID for the swage tool was turned to 60mm and the tube came out at 59.4mm so I am going to open up the tool to 60.50mm and see how it goes.
 

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Why not get a set of bellmouths for the trumpet the carbs came from and modify the airbox as required to accept them? You might have to buy a complete airbox to get them, but they should be available. That's where I usually get my bellmouths from...The bike the carbs came from.

You may be cheaper buying a complete airbox with connectors, or get new ones at around 30 bucks a pop.... Ouch that's expensive. See if the wreckers have a cheap or damaged airbox you can save the trumpets from. Or find a GSXR or similar with the same sized carbs and get a set for that.
 
Why not get a set of bellmouths for the trumpet the carbs came from and modify the airbox as required to accept them
For me I get just a kick from making it myself rather than buying off the shelf. Of course there are exceptions but this looks makeable!!!
 
XS750AU said:
For me I get just a kick from making it myself rather than buying off the shelf. Of course there are exceptions but this looks makeable!!!
Very interesting,i'm looking into doing something like that soon too.
Thought about 3d printing the whole piece though.

Gesendet von meinem SM-A310F mit Tapatalk
 
Thought about 3d printing the whole piece though.
We use 3D printing a bit at work to make up proto plastics. Its OK, but nowhere near as strong as a proper injection moulded part! Very important that when you organise the print path that you alternate the direction with each layer, like laying bricks. You have to tie each layer together.
I chose not to print and steal will be infinitely more durable, plus I can use tubes with a much much thinner wall, so more air can get through. I opened up my swage tool to 60.5mm and the tubes came out very well.
Spent Saturday at a mates place and built up the header with new bends. Finished off the header this morning by cutting and flaring the head ends. Header and complete exhaust system is now almost finished, a little more cleanup required.
Ready to strip down and paint the frame now and then just about finished :D
 

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Some nice work there! I am toying around with (roughly) the same idea, mainly because the VM36s need better filters than El-Cheapo (Emgo) on the back as they are restricting airflow notably. (Which is good if you're running CV-carbs as the slides don't flutter as much, but I am running classic smoothbore carbs... and just running stacks is not an option as the sidecar is parked outside nearly all the time.)

Cheers,
Greg
 
Plan B
Found some 60mm OD ally tube in my material stack. I had a 60mm OD hole saw, that does cut a little over size. The plan being to make up the filter tray out of 1.8mm sheet formed around MDF forming plates with a fare amount of hammer time. Needed to anneal the corners once.
The tubes were cut to length and then bored out to 55.5mm ID and the a small groove cut into the OD to engage with the filter tray. To assemble. I modified my swage tool to expand the ally tube and rivet them into the tray. No welding required and tubes are rock solid.
Now have to make up the foam filter.
Hope that all makes sense. ;D
 

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Let us know how you fared as that looks mighty interestin and please also let us know about the air-filter you're using, I've had a similiar idea, with regards to the airbox, but haven't got round to doing anything about it until now.
 
please also let us know about the air-filter you're using
I am using open cell polyurethane as my filter element. Unfortunately the foam I have is bright yellow, which does not look that good. Think I need to get some grey foam. I also have a light expanded metal mesh which I am going to try as a cover/retainer over the filter.
 

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Completely stripped the bike down today. Took me 3 hours. This time I lay the the engine and frame on its side and took the frame off the engine. Don't know why I have not used that method before - hell of a lot easier and no scraping/scratching the frame.
Now I am completing all welds and cleaning it up ready for painting.
 
Can´t wait to see it finished!
May I ask you how you made the "tray" with the three holes for the air filter element?
Looks really nice,like a dye press or something,no welds...

Thanks!
 
May I ask you how you made the "tray" with the three holes for the air filter element
Yes - guess the photos don't show the actual process. Doh!!!
In the photos you can see that I cut the blank out of aluminium sheet with a 20mm perimeter, and clamped it between 2 medium density fibre (19mm MDF) board former patterns. Probably should have annealed the corners first to make the forming easier, but you live and learn!!
Then I clamped the formers and sheet in my 8" vice and used a nylon hammer to start beating the perimeter over onto the former. Moving the part in the vice as needed. The straight sides form easily and can be done without annealing. In the corners there is an excess of material that needs to thicken up and grow out if the corners are going to be smooth. The MDF is a bit too soft to really bash out the corner. So I removed the ally tray from the formers - annealed the corners with a propane torch - and then used some solid 63mm steal round as a former in the vice and a steal hammer to finish the corners.
When the flange is fully formed the flange edge is far from flat due to the corners growing, so I clamped it onto the mill table and cleaned it up to a flat surface.
Final process was to cut the 60mm holes for the carbi inlets. The 3 holes used to clamp the MDF formers together, were at the correct spacing so those holes were used to guide the hole saw in the mill.
All in, including making the former patterns there was about 2hrs work in making the tray and probably 5 hrs for the whole air cleaner as you see it.
The MDF former pattern is pretty much stuffed now, with a steal former pattern it would be much easier and quicker to form the aluminium, but much more work to make the patterns.

Definitely no welds.
Cheers
Tim
 
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