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Old 03-26-2012, 05:51 AM   #181
sakurama OP
on an endless build
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So getting the bike running for that video was exciting but premature. It's one thing to get the beast to start it's another to get it to work correctly. One accelerator pump wasn't pumping and that's a problem as the pumper is integral to the carb and it's also your cold start or choke on a carb that doesn't have a choke: you twist the throttle a few times to let the pumps flood the cold engine with raw gas and you can start the bike. Also, the point of the FCR's is that the pump gives it gas when you whack the throttle open. One isn't cutting it.

So all day Sunday I wasted trying to figure out why. I'm a smart guy, I can solve this... Nope. I took it apart, blew out the passages, checked the diaphragm for tears, checked the physical function and found nothing. I filled the flood bowl with alcohol and tested the pump and it sputtered. I took the good carb apart and checked it and it shot a good controlled stream of alcohol through the orifice. I examined the parts against each other and found that the bad carbs float bowl had a very small casting imperfection on the mating surface and on my surface plate it rocked whereas the good carbs float bowl sat flat. See the gaps of light here?

Okay, I found it! I took out some 400 grit wet/dry and proceeded to lap the bottom of the float bowl with some Dicom (blue dye) to check it.

So you can see there was a very definite high spot. Once I got it nice and flat I put them both back together and...

...they both didn't work. Son of a bitch! Oh, forgot something.

Hooked up the tank and ran the fuel pump and the good one worked and the bad one didn't. I can only imagine that the one diaphragm has some tiny imperfection that I can't see. I was frustrated and fed up. Three wasted days on these carbs and they still don't work. My shop time is far and few between and wasting any of it is massively frustrating. I needed some progress of some sort to rescue my weekend...

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Old 03-26-2012, 06:04 AM   #182
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'Sorry for your carb troubles, but I'm sure they'll be corrected soon.
I'm anxiously awaiting your TPS mount drawing, and if you were so inclined, I'd even buy a mount from you if you'd care to make another.

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Old 03-26-2012, 07:15 AM   #183
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I didn't want to start on the exhaust because it's a rather involved project that I wasn't all that sure I wanted to tackle with limited time. Once the carbs became hopeless my hopes of getting the bike running this week or this month went out the window so what the hell - I'll make an exhaust. Since I still needed the old one in case I got the carbs sorted I decided I'd only work on the front header. I don't have real idea of how the exhaust will look/work but I have a few requirements: 1. It has to be better made than the stock one, check! 2. It has to be easier to get on and off. I'll solve this with springs instead of bolts. Check! 3. It should look a little different. 4. It should sound like bloodly living hell.

From the sound of the bike with the FCR's when it ran I think 4 will be no problem. The carbon Leo's I have will only help.

So, how do you make an exhaust? You start with pre bent tubing of the correct diameter (1.75") in different radiuses. Radii? Holy cow, it is radii - who knew! I order from Burns Stainless but there are a few places. No one bends their own tube - too hard - so you buy them in different radii and then cut and twist and shape. Here's my box of tube that will become my exhaust.

In my case there aren't a lot of places the exhaust can go - the 950 is a tight package with very constrained packaging. I considered running it low but I never liked the look and you run into center stand problems. I'm planning following the stock path up to the collector and then I'll change it.

So, I pull the front header and, starting at the front, compare the bend to my collection of radii, match it and then cut.

I use a red sharpie and by eye I mark where I think the cut should be. Little note about my wooden block - 1.75" hole saw and then cut it in two and it holds the tube in the vise perfectly for cutting.

Then out comes one of my new favorite tools - the Dewalt portable band saw. This thing is the shit and makes quick accurate work of slicing the tubing.

I use these little clamps from Ice Engine Works to hold the tube - first time using them and I'm undecided if I like them yet. Anyway, you cut the tube, twist the bend and then, when you have it in the angle, orientation and direction you want make a couple of witness marks to mark position.

I was using the clamps to hold a few pieces of tube and they were slipping and so I figured it was time to start tacking. Tack welding is making a very tiny weld of the joint to simply hold the tubes in position.

The process continues; look, measure, estimate, cut, align, hold, tack, repeat. After each tack you hold the part up and check the fit. If it doesn't look right or doesn't fit right you just break the tack and redo it. It could be described as tedious but as I kid I loved Legos and blocks and as an artist I have good spacial sense and I enjoy the process. Perhaps more than any other thing I love making exhausts - it's relaxing and methodical and rewarding.

The front header went surprisingly fast so I decided to tackle the rear header. Again, remove and compare.

The rear is incredibly tight and it's a royal bitch to remove. It's like those bar games where you have to take the ring off the little twisted steel bar. I didn't want mine like that so I went with a donut so it would be tighter. Donuts are made differently but function the same.

Some more cutting, tacking and fitting and we have this.

At this point I'd worked way faster than I expected and I was suddenly at the join which I'd not considered fully so it seemed like a good place to stop for the night. I was also very tired. I want to make the join something a little special so I need to think about it. Stock is just a 1/2" tube joining the two headers and that style is typically used for sound more than performance. I'd like to do an X style cross join and I need to think about it more. It will be difficult to make, perhaps harder than my skills allow, but it would be cool. Also, it's time to consider asethetics. When the tubes join they should have similar curves and this is where you really need to take your time. I also need to order springs and the clamp mounts for the carbon pipes. I'll probably also need more tube if I'm to make my own X cross over. Here's my inspiration:

That is a Ti pipe and the fabrication is off the chart. That crossover alone is a work of art and wonder but I'm going to try it. What the hell right?

And as a reminder to myself here are the pipes for this bike. Now I'll have that number for calling Leo.

And here are the two together.

Not sure when I'll get more shop time but I'll make calls today and start getting the parts I need and to figure out the carbs. So the carbs were a bust but the exhaust is going better than expected.


sakurama screwed with this post 03-26-2012 at 08:13 AM
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Old 03-26-2012, 12:18 PM   #184
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Gregor, I've read this thread from start to finish today....what an incredibly talented and interesting guy you are...

Here are a couple of examples of the x-over design.

Both from Tigcraft Japan (sadly they don't make for a KTM) and they're from an Aprilia RSV1000.


PS - what make are the fork leg protectors you have fitted - they look like they're a straight bolt on replacement?

deksawyer screwed with this post 03-26-2012 at 12:40 PM
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Old 03-26-2012, 01:21 PM   #185
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Sir. You are brute talent and skill.

Wow some cool work and the writing is great.
KTM 950(1190) Adv-s, Soon to be Project 1190
KTM 530 EXC-R 08
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Old 03-26-2012, 03:14 PM   #186
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I don't have a KTM (yet) but threads like this and Pyndon's are the shit and will be invaluable when I get around to getting one. Until the next update,
Scott - Semper Fi
'04 BMW R1150GSA, '05.5 KTM 950 Adventure
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Old 03-26-2012, 04:15 PM   #187
sakurama OP
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Originally Posted by deksawyer View Post
Gregor, I've read this thread from start to finish today....what an incredibly talented and interesting guy you are...

Here are a couple of examples of the x-over design.


PS - what make are the fork leg protectors you have fitted - they look like they're a straight bolt on replacement?
Thanks - that is an inspiration. I can only hope to weld that well someday. My plan is to start with some coupons and test tubes and then begin with the welds you won't see and work towards the ones you will last keeping in mind that I'll have to balance my heat to keep it from warping.

The fork shrouds are I think KTM 85 parts if I recall correctly - its been 8 years ago that they were put on. One bolt won't line up but the front two will.

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Old 03-26-2012, 04:20 PM   #188
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Well, at least the scope for the project was kept to the bare minimum...

Doubletake Mirrors- Folding D/S mirror that is both useful and indestructible.

Dual Sport Riding Techniques DVDs: Clear instructional DVDs to improve off-road skills.
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Old 03-26-2012, 04:40 PM   #189
sakurama OP
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Originally Posted by neduro View Post
Well, at least the scope for the project was kept to the bare minimum...

Ned you bastard! Congrats again!! Wish I could make it to this years Nedfest as I'm sure it'll be epic. I'll drop you a note when I'm on my way through or I'll see you at the National for sure.

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Old 03-27-2012, 11:29 AM   #190
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What an awesome thread! Thank you for documenting all of your work. You really are very talented.
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Old 03-28-2012, 05:57 AM   #191
sakurama OP
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slow progress

On Monday I spoke to Sudco who's first question was, "Did you buy them from us?" and when I said, no, but I'd just like some advice I got the brush off and was told to contact KTM Twins who could then contact Sudco. Sadly I see this as being a rather protracted process. When I explained all I'd gone through the tech did admit that there were problems sometimes in the finish machining and that the problem might be internal. Yesterday KTM Twins responded that they were very busy and they try to respond to me in the next day...

So, onward with the exhaust.

As I was cutting and tacking the pipes and got close to the join I realized that I couldn't hope to be accurate by just holding the pipes up and guessing at the placement. I needed to start to lock down the actual locations if I hope to make this right and that meant I needed to create my header flange. Time to call in some favors!

Meet Isaac of 4th State Metals. He was my neighbor and friend when I lived in Bed Stuy and he's an all around creative fabricator who builds giant art for artists, wild architechural elements and even instruments for Bjork! Isaac has a plasma cutter and for the cost of a few beers agreed to take my sketch and cut me some 304 stainless flanges that I could then machine.

I don't do CAD so I photoshopped a drawing and emailed it to Isaac and here he's transferring it to Solid Works for his plasma.

Then to the supply racks to look for some 1/4" stainless.

And finally onto the cutting table where the CNC plasma slices the stainless into raw shapes for the flanges. Plasma isn't water jet so the final finish is undersized for me to finish on the lathe and mill.

There are the raw parts - one extra to practice with. Back at the shop I use a die grinder to remove the slag from the parts. The plasma leaves a hard carbonized shell which will eat up lathe tooling so it has to be removed.

Next I got a hunk of stainless pipe and attempted to turn it down to a smooth finish. Thankfully this isn't an axel as I've never taken the time to really level and set up the lathe so the dimensions are off from one end to the other by a few thou.

Then I slice off 1.1" parts in the cold saw that I rescued and restored from some Harley buffoons last year. They said they never got it to work and when I got it home it was obvious why; they'd tried to plug a three phase motor into 220 single phase and melted the whole harness. It was a mess but for $300 bucks it was worth the hassle as these saws go for upwards or $2000. They spin slow and pump coolant onto the blade and make a really nice perfect cut fast.

Then the piece I cut off is turned in the lathe to accept the outside diameter of the header pipe with an interior shoulder to land on.

The flange is then turned open to be a snug fit for the sleeve and then is taken to the mill where the holes for the studs are located and drilled.

This is what I spent the day working towards - three complete flanges.

Sadly, I decided to just go ahead and try welding them. I'm still learning my heat control and while these are perfectly functional they show that I was dumping too much heat into them as I welded them. The upside is my last one was better than my first and this whole exhaust is simply a learning experience for me.

It does tell me that welding the thin wall tubing will be a real challenge but I'm looking forward to it. One of the great aspects of building an exhaust as opposed to a frame is that all the elements of building it - precision, fit, heat control and management - are all important but none of it is mission critical. I won't die if one of my welds crack. So, as I progress in my skills toward the ultimate goal of building my own motorcycle from scratch this is a good learning experience.

It's hard to say when I'll get back to work on the bike again. Hopefully when I'm back in two weeks I'll get some time and in the mean time I hope KTM Twins will be able to get my carb issue sorted out and back so I'm not waiting on that.

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Old 03-28-2012, 06:06 AM   #192
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Great pics and report!
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Old 03-28-2012, 06:07 AM   #193
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Quite the project my friend!
KTM 950 Adv. "S"...'06 KTM 525 EXC...
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Old 03-28-2012, 03:25 PM   #194
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that's great work man, sorry about the carb issues, I hope you get them solved.
I've had nothing but good experiences from KTMTwins
DRCOOL rides with me
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Old 03-30-2012, 05:40 AM   #195
sakurama OP
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So not much more to update the thread with. I've spoken to Ron at KTM Twins and he asked for the whole FCR kit back, filters and all. If they replace it I'll lose my new tapered intakes but at least I'll still have my TPS bracket. If they replace them I might try to swap them for 41's now that I know it's going on a 990 SMR with the giant intakes. This new engine could use all the air it can get. If they don't that's fine too as I'll run the carbs as 39's and then, if I decide I want more air, I'll bore them out to 40 and see what I think. That will be a fun operation; boring a set of $1200 carbs.

So, one thing I forgot in the last thread but I thought I'd include is just a simple tip about using digital calipers. You do have digital calipers don't you? They're so cheap now there's no reason to not have a set kicking around in your tool box and they're useful beyond belief. I actually sewed a pocket for them on my shop apron so they're always on me.

Anyway the tip! Finding the center to center distance of any holes can be a bit frustrating but here's an easy way. Measure one of the holes:

Next "zero" the caliper with that dimension:

Now measure the outside to outside of the holes and you'll have the center to center perfectly accurate. Just remember to rezero them!

Easy peezy. That's all, just a little tip I've found to be really helpful and fast.
__________________________________________________ ______________

Okay, now onto the regular progress.

So I wasn't happy about my flange welds and it bugged me. My welding set up is in NYC and when I'm in Portland I can't practice so I decided to sign up for a tig welding class in Portland. In fact, while researching welding classes, I discovered that Portland is a mecca of "making" and there's a class this fall on titanium bicycle construction. Two weeks and at the end you have a titanium frame. I'm so in. Anyway, I'm looking forward to some formal instruction when I get back home. Time to step it up.

In the mean time I decided to at least make some parts I'll need for the exhaust - namely spring anchors. It's a very tiny part but one you can't buy and have to make. The anchors are made from 3/32" stainless 308 welding wire and are just bent "U" shapes turned up at the ends. Simple right? Well, try bending one with pliers and it's not so simple and it's worse if you need 20 or so. Time to make a tool.

To the notebook and Chris shows me some examples of ones he's made:

A little bit of machining and welding and I've made a little tiny wire bending tool that makes a 1/4" 180 bend. Insert the wire into the drilled hole...

Pull the handle around...


Take all your little "U" bends over to Chris' side of the shop and put them on his press brake nicely aligned...


And there you have it. Exhaust spring hangers ready to go.

Next installment will be in three weeks time and I hope it involves a new set of carbs and new welding skills.

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