KXF 250 Problems

Weeeeelll, I have not posted for a while as I have been busy with my photography. Over Easter weekend I rebuilt a KXF 250 and had a problem that puzzled me. Check this out, I posted the story on this forum



Yee Haa fixed!

Yee Haa fixed!


Motocross berm action shot

Here is my favourite photo from last weekend. I wish it was a bit sharper but that is the pay off to capturing the motion. I love the roost trailing back around to the start of the berm railing action and the wave flowing over to the right.  Worth standing out in the tropical hot sun for.

_Y9A7077 Berm wave

Top End Moto Cross Club 26th May 2013 Natural Terrain Race Meet

Here are all the pics that I took on Sunday, between racing (circulating) myself! I know I missed some classes; Sorry ( Maybe next time). I have processed these in one go, I have not cropped or enhanced these images. I have also saved them in lower resolution for quicker upload. See my next post here where I will show a few shots at full resolution/size and you can see how the Pics look (time permitting). I have bought a new lens and the sharpness is much better than previous posts. Although my set up is not “top of the range” professional gear, I believe I can still produce reasonable shots that could blow up to at least A3 size. 

I cant make any promises as time is always the factor, but if you catch up with me at the track and provide me a memory card (Maybe a donation of your choice – A beer or two) and details of the pics you like I can load these onto the card for you to process how you like, maybe even get a sticker for your hauler at a sign makers. I can load them as Jpeg and/or Raw image which can be processed and printed at any Photo Print outlet, then you can frame them or throw darts at them.

Anyway have a look.

IMG_5374 IMG_5377 IMG_5379 IMG_5385 IMG_5389 IMG_5392 IMG_5393 IMG_5394 IMG_5396 IMG_5397 IMG_5398 IMG_5399 IMG_5401 IMG_5403 IMG_5405 IMG_5406 IMG_5407 IMG_5408 IMG_5412 IMG_5414 IMG_5415 IMG_5416 IMG_5417 IMG_5418 IMG_5420 IMG_5421 IMG_5422 IMG_5424 IMG_5426 IMG_5431 IMG_5432 IMG_5433 IMG_5439 IMG_5440 IMG_5447 IMG_5449 IMG_5450 IMG_5458 IMG_5459 IMG_5460 IMG_5463 IMG_5465 IMG_5466 IMG_5468 IMG_5470 IMG_5472 IMG_5477 IMG_5478 IMG_5479 IMG_5480 IMG_5481 IMG_5483 IMG_5484 IMG_5485 IMG_5486 IMG_5487 IMG_5488 IMG_5489 IMG_5490 IMG_5491 IMG_5492 IMG_5493 IMG_5495 IMG_5496 IMG_5497 IMG_5498 IMG_5499 IMG_5500 IMG_5505 IMG_5508 IMG_5509 IMG_5510 IMG_5511 IMG_5512 IMG_5513 IMG_5514 IMG_5515 IMG_5517 IMG_5522 IMG_5523 IMG_5526 IMG_5527 IMG_5529 IMG_5530 IMG_5531 IMG_5532 IMG_5533 IMG_5534 IMG_5536 IMG_5537 IMG_5538 IMG_5539 IMG_5540 IMG_5541 IMG_5542 IMG_5543 IMG_5544 IMG_5545 IMG_5546 IMG_5548 IMG_5552 IMG_5555 IMG_5563 IMG_5566 IMG_5569 IMG_5570 IMG_5571 IMG_5573 IMG_5576 IMG_5579 IMG_5580 IMG_5581 IMG_5582 IMG_5583 IMG_5588 IMG_5592 IMG_5601 IMG_5602 IMG_5603 IMG_5604


Moto Transporter Trailer stage 4

Roof panel in place

Roof panel in place

Trailer build stage 4003 Trailer build stage 4004Above 2 shots show the wheel guards cut out and ready to be glued in. I love this Composite panel it is so workable. like a cross between wood and metal.

Trailer build stage 4007 Wheel guard support angles ( I used some 20 x 20 x 1.2 aluminium angle). I used adhesive between all parts to reduce corrosion and vibration.Trailer build stage 4010Here is the adhesive sealant gunned on and ready for the guard fitment.

Trailer build stage 4013 Trailer build stage 4014Guards on. I used double sided tape to hold the panels whilst the polyurethane sealant goes off.

Trailer build stage 4015 One of the curved panels fitted up. See the Clicko pins I used to hold the panels in place while I marked out the notch outs etc. I was a bit anxious about curving the Composite panel around the front of the trailer, but it pulled around nicely, nice and snug to the frame work. Pleaser!! Trailer build stage 4016 Trailer build stage 4019Really starting to take shape now. The interior looks quite clinical

Trailer build stage 4021 Cant wait to get the tinted angry eye screens fitted. Definitely starting to see the vision I had from the original drawings. Trailer build stage 4023Nearly there just some wiring and trimming off edges. I will also need to fit some channels for the Moto X bike wheels to lock into I will use these hold down devices http://www.kyaracing.com.au/ Check them out they are a great invention.

The trailer has been a long project and has provided much joviality among my work colleagues, I suppose I did start it in October 2012 and now February 2013 and still not registered yet. I hope to get it registered this week and then finish off some of the trimming later. I will post finished photos. I want to get a sticker made for the rear door and intend using the white inner walls as a photo gallery. The sticker for the rear door will based on this photo.

Leg forward

Leg forward

Moto Transporter Trailer Fabrication Stage 2 – Body work Frame

At last I am back to working on the Trailer project. I took these photo’s back in November  so it is high time I sorted out the next stage of construction post.         The body work frame here is getting welded to the main chassis of the trailer as I go, using a MiG welding machine with 0.9mm solid wire and Argon/Co2 Gas mix. I worked out my design using DraftSight which is a very good free program  for 2D drafting (Just type draftsight into Google).

I had a stack of 20mm x 20mm Square Hollow Section (SHS), which I scrounged from a clean up at a mates and set about cutting all the lengths as per the Drawing I produced on Draftsight. I started by tacking together the rear part of the bodywork frame.

 Pleas feel free to comment or ask any questions re the design and construction.
I had a stack of 20 x 20 Box Section or Square Hollow Section to use for the frame work

I had a stack of 20 x 20 Box Section or Square Hollow Section to use for the frame work



MY design of the body work using Draftsight a free program.

My design of the body work using Draftsight a free program. Here I have switched off parts of the drawing such as axle and wheels to only show the body work framing.

Body Frame Construction3 11-11-12I decided to make the guards by constructing a SHS frame which I will sheet with Aluminium at a later stage.
Body Frame Construction4 11-11-12

Body work Frame now taking shape

Body work Frame now taking shape. My son came and helped with wiring the lights I have used PVC conduit which will tuck away nicely along the Channel section out of harms way. I will seal all ends with silicon to stop the dreaded ants making home inside the conduit.

I added some diagonals to stiffen up the whole trailer. This made a big  difference to the overall stiffness.

I added some diagonals to stiffen up the whole trailer. This made a big difference to the overall stiffness. I have not yet added these to my drawings, but it is fairly easy to see how I have created some triangles which provide extra rigidity. 

I used some 50 x 5 Galvanised Flat Bar which pulled around nicely without having to roll it.

I used some 50 x 5 galvanised Flat Bar which pulled around to form the bull-nosed front nicely without having to roll it.                                                                                                                                                            I designed the trailer to be fairly aerodynamic using a bull-nosed front like a horse float, this is coupled with a sloping roof section which will lift up on gas struts to allow access for loading and unloading bikes.


I used the measurement I got from the Drawing I did up. When I laid a piece of SHS along the top it looks like the uprights will match up pretty well around the top.

I used the measurements for the uprights around the bull-nosing I got from the Drawing I  created. When I laid a piece of SHS along the top it looks like the uprights will match up pretty well around the top when I add the rolled sections of the frame.                                                               NOTE: I spaced the uprights to match the cladding sheet widths so that seams will fall directly on the upright member. I intend to us Polyurethane adhesive/sealer to affix the composite cladding panels to the frame work with minimal rivets. 

I needed to roll some 20 x 20 SHS to suit the radius of the sloping top. I managed to gain access to a set of section rollers at previous employers workshop for this. the next post will show these rolled sections installed. The top rail around the Bull Nosing could be  constructed from Flat bar which would have to be cut and fitted as you go around the top edge as this actual profile will not be a straight line. Typically me, my design has not made construction easy, but the challenge of working it out is fun.

Stage 3 will be uploaded shortly.

Moto Transporter Trailer Fabrication Stage 1


20-10-12. Off to start fabrication of trailer.

Material has arrived from merchants, after a bit of messing around!

After cutting the lengths, I laid them out out to check the actual design sizes compared to drawing. Looking good!

The cold saw cuts produced a great mitre joint. I will grind a bevel on the edges for welding.

Marked out with chalk, so that it is easy to see when Oxy-Acetylene cutting.

Not too bad for a free hand cut!

I set the perimeter frame up square and positioned the spring hangers and tacked them in place.

Notice how I have welded around the toe of the vertical flange of the steel angle. The toe is the biggest stress raiser and a poor weld here will allow a crack to propagate as the trailer will be subjected to dynamic/cyclic loading.

Spring hangers welded completely around with approximately 6.0mm fillet weld

Do not weld across the draw bars where they transition the main frame a weld in this position will create a significant stress riser and could propagate cracking of the weld which could carry through the material.

I cut the Channel connections in for a flush finish. After welding I ground the weld flat so that the floor will sit nicely in the frame.

Axle in, so I can wheel it about.

Base frame together.

I set the floor into the Channel frame in order to keep the floor height lower to make loading the bikes easier.I can also place tie down points on the top flange of the channel. I saved 3 inches (75mm) doing this.

Next stage will be to start on the frame work for the body.

Suspension Matters Review

I recently sent my Suspension to Dave @ Suspension Matters in Queensland (See my Links). This is the first time I have invested cash in such a caper and was anxious to check out the result. Despite the longer than anticipated time for the package to return within grasp of my sticky little fingers, I am thoroughly impressed with the product.

Being busy at work held me up from getting it set up properly, but initial feel of the bike, after a brief ride, was that in felt way smoother and more controllable, especially entering a turn. The front did feel a bit too stiff at first but when I bled the air a lot came out, it must have been the fact that it was shipped from a cooler climate to Darwin’s oppressive heat and the temperature increase had built up quite a pressure in the front forks.

Anyway, I played with the clickers some more, and I think I have it fairly well “dialed in”, but the terrain on my own track is fairly smooth so I am hoping to get to the local race track next weekend and set it up there.

My old steed is now a completely different bike to ride, firstly I noticed how the rear glues to the ground on acceleration and just drives forward leaving a fat groove as a calling card.

Also, as the bike no longer ducks and dives under braking into a rough corner entry, it is so much easier to point and shoot. The bike turns in so well, as now the balance is correct, therefore improving the steering geometry.

Now, I am an old sloth of a rider who has a fear of jumps. I can now put it down to having ridden a bike incorrectly set up for so long. With this re-valved and re-sprung suspension, I felt confident (after a couple of jumps to the side) to hit our home track double for the first time. No kicking out side ways, no wallowing unruly landing, just straight positive drive and a landing with a “Pad” sound and no real noticeable landing just a flow back into the terrain and drive away.

I am very happy with the bike now and so look forward to giving it a proper go on some more cut up terrain. For now I am quite excited about how my old bike feels so fun inspiring. I would highly recommend Dave at “Suspension Matters” although I have never payed to have this type of set up before and don’t have others to compare with, I do have good friend who put me onto this business, and I trust his more experienced recommendation.

A leaving thought.

I remember unpacking a KTM 125 SX, the first brand new bike I had ever bought. I jumped on it and rode around for about 3 minutes, I then suddenly had the impulse to line up a 1 meter high ant hill and I just “bunnied” over it. That bike just made you feel like doing it, well now my old YZ250F feels just like that.

Fatigue Fracture Fix

My suspension arrived from Queensland this weekend (I will review soon), and as I went to fit it I remembered that during dis-assembly I managed to shear the long bolt that passes through the top of the frame and secures the rear sub-frame. I had intended to order a new bolt whilst the bike lay forlornly dormant, but the ol’ “out of play”, “out of mind” rule obviously reared it’s head. So here I am, it’s late Saturday arvo and I’m miles from town and anxious to check out that suspension, I hunted in the nuts n’ bolts tubs and turned toolboxes upside down, it’s amazing what long lost friends you come across doing that, like the cable-tied together clutch perch that gets you to the finish flag of an enduro,  or the old BSA fork top-nut I once fashioned a puller out of because it happened to match the thread of the magneto on an Ossa trials bike I once owned. Well you never know, I may buy another old 1974 Ossa one day!

Anyway no luck with a long bolt so the next option was to fix the broken one.

Classic example

Now here is a classic example of a Fatigue fracture. Looking at the surface of the break at around 6:00-7:00 pm (clock wise as you look at it), it appears as if a large load has, most likely, propagated the initial crack which started right in the groove of the last thread where it transitions to the bolt shoulder (a common stress riser). The bolt, now weakened, has continued to crack in increments whenever a larger than average load was placed on it (my fat ass on the seat). This is evident by the succession of parallel lines in area “A” which have worn smooth as the two semi attached parts would have been continually rubbing together. As the crack increased over time or number of load and unload events (Dynamic/Cyclic Load), it progressed to a point whereupon, as I went to undo the bolt, which had the threaded part corroded and well fixed into the sub-frame, it sheared. This is evident by the rough fractured surface seen in area “B”. This is the sort of clues relating to failure that air crash investigators examine.

broken bolt from a wheel of a lorry / gebroche...

broken bolt from a wheel of a lorry / gebrochener Radmutternbolzen von einem LKW (Photo credit: Wikipedia)

English: image of fatigue of material (crankshaft)

English: image of fatigue of material (crankshaft) (Photo credit: Wikipedia)

I had soaked the sheared part in penetrating fluid when it broke off and then promptly forgot all about it. I expected the extraction of the threaded part from the sub-frame would be a tricky operation. I decided to drill it out and fit a Heli-coil, as I started drilling the threaded slug simply unscrewed itself with the twisting action of the drill. It was obviously the four week soaking in penetration fluid that did the trick!

I delved into the nuts n’ bolts tub and found a Stainless steel countersunk screw with the same thread diameter and pitch.

I then cut the original bolt down a bit, so that if it were to shear again, at least I would have a stub left sticking out to get hold of to assist in removing the threaded part.

I then prepared the ends for welding by grinding a bevel to each part. this gives somewhere for the weld metal to sit.

I Prefer to TIG weld this type of repair. TIG welding resembles Oxy-Acetylene welding in principle, it just uses an electrode to create an arc to melt the part as opposed to a flame. I used a steel welding rod, a lot of people will say you must use a Stainless Steel filler rod if you are welding Steel to Stainless Steel.  But, I say why waste money when the weaker material will mostly be the steel part anyway?

Glowing Red Hot. Just how welders like it.

Light grind

I gave the weld a light grind to remove excess weld metal taking care not damage the thread.

After I cut the old screw head off I then feathered in the start of the thread, I always prefer to use a file for this as it has more control and feel. If you perform this operation with a grinder one false move can stuff up your work thus far!

File rather than grind a chamfer

Wallah ready to install

Now to get that bike together and haul’n.

Moto Bike transporter trailer

I have decided to build a trailer to carry my bike to the track instead of using the Ute(Utility). That way I can keep some gear in it permanently and make it easier to be able to get a ride in, after work during the week. Now that’s got to be good!

So far it is still in design mode. I made a rough sketch and went out and purchased axle., springs, shackles, U bolts, Trailer hitch, electrical plug, compliance plate, reflectors, hubs and bearings. I pinched my son’s spare alloy wheels! So now I need construction materials and lights which I will probably go with LED units.

scribbled ideas

I then measured the spring set up and produced some drawings using draftsight  http://www.draftsight.com

I am ordering the chassis frame materials tomorrow. At the moment I still deciding on which material to clad the framework with. There is a great aluminium composite board made from thin sheets of aluminium adhered to a plastic core. it comes coloured with a different colour on each side. Sign writers use this material, it is light and flexible. Anyway, that material is high on my choice list at the moment, I just need to work out the best way to fix it to the frame. Initially my idea was to clad the trailer in Clear Anodized Aluminium sheet and fix this to the frame with a good quality polyurethane sealant adhesive using a minimal amount of rivets.

I will continue to post news on this project as construction begins.

Aluminium Fuel Tank Construction

Last year I developed a split in my fuel tank. This was during a Darwin Motorcycle Club race meet, I ended up riding my son’s Kawasaki for the last race. Wow, what a Rolls Royce of a bike compared to my old machine. I remember hitting a series of square edged holes leading into a fast sweeper and tensing for the hammering but I was pleasantly surprised to find his bike just floated over it, as smooth as! Anyway, I just could not afford a new tank at the time, but I had access to a welder and some sheet-metal equipment and I thought, “well I could afford some time to build a new tank”.

I started off fabricating the base of the tank and had to hand shape the section over the main frame member as it curved in two directions. I welded in a plate to fix the fuel tap to with two blind holes threaded M5.

Underneath, showing seams I used to construct the shape

Shaping the base panel involved a bit of stretching and shrinking plus occasional annealing as aluminium will quickly work harden. Once I was happy that this part sat in place over the frame I looked at starting on the side sections. I made some cardboard templates by wrapping the cardboard around the sides of the plastic tank and trimming this down until it was pretty close. I then used these templates to cut out the aluminium sides. The material I used was 5000 series 1.2 mm thick Aluminium.

Base with sides after initial shaping.

I welded in some aluminium round bar that I drilled and tapped blind holes into for the various mounts. I had to use the radiator cowls to position these accurately.

Shaping the sides took a while and the right hand panel had to have a relief cut and shaped in for the radiator cap.

RH side curved in for Rad cap

I continued to work the sides until I was satisfied with the fit for the cowls and mounts. I then fabricated a top panel using a cardboard template to get the basic cut out shape.

Top Panel taking shape


Taking shape

I purchased a fuel filler neck with a suitable cap from a camping and caravan supply store and welded this into the top plate.

Nearly completed

It was a time consuming project and I would hate to charge someone for the commercial hourly rate. But I enjoyed this sheet metal project. I actually completed an apprenticeship as a Sheet Metal Worker in the early 70’s so the skills were there. But as with any project enthusiasm is the main ingredient. Projects such as this should be tackled one part at a time, this avoids being daunted by the complexity of the task, plus each part completed give satisfaction and inspiration to continue.

I welded the tank with a Fronius AC/DC TIG welder in pulsed arc mode and used 5356 filler rods. When my day job takes up less of my time I would like to hand build an AC Cobra replica. Now that would be a photo story!

Shelby AC Cobra

Shelby AC Cobra (Photo credit: Wikipedia)

Pretty Retro Hey!