Messages

61

General Two Stroke Talk / EFI Bighorn

« on: April 29, 2013, 11:54:53 PM »

I had one ( 1971 F5 350 ) when I was 16, not the same one, with a Kawasaki Hot Kit. Supposed to produce 44HP.
 At 7000 it had about 15HP, at 7500 probably did about 30HP! Would go through to 9000. NOT a good trail bike. Either monstrously out of control or bogging.

62

General Two Stroke Talk / EFI Bighorn

« on: April 29, 2013, 01:47:27 AM »

The TT doesn't get a look in.
You still don't have that F81M do you?

63

General Two Stroke Talk / EFI Bighorn

« on: April 28, 2013, 08:46:57 PM »

Any time, book that ticket.

64

General Two Stroke Talk / EFI Bighorn

« on: April 28, 2013, 07:42:51 AM »

There you go Racer X , I do get off the seat sometimes.
Click on the picture and it will take you to lot's of photos from the final VMX round in NZ.
Meagan is there riding the 175IT and the TT500.

65

General Two Stroke Talk / EFI Bighorn

« on: April 23, 2013, 12:21:24 AM »

I have that frame ( Meagan's bike ) and have thought about it, the F9 gearbox has not been that good at changing gears. I decided it would be foolish to have such an old engine in a new frame with a gearbox that I had to fight with. As it happens when I had the gearbox apart to fix the bearing I found that reason for the problem. Now it changes smooth every time. No, I'm keen to finish this new 360 engine specially made for Meagan's YZF frame. I keep promising to do stuff for other people, I need to just lock the door to the workshop and tell every else to bugger off.

66

General Two Stroke Talk / EFI Bighorn

« on: April 23, 2013, 12:04:48 AM »

Well we did it, The Bighorn, second in the VMX series. Certainly the bike is good enough for first just not the rider. EFI performed flawlessly all season only problems was a foot peg falling off ( this was the only DNF ), gearbox bearing failure ( at a trail ride but still finished the ride ) and a regulator issue that was found half way through the season but this didn't affect five lap races. I'm not sure if an EFI twostroke has finished with a place in a national MX series before? I would imagine it would be the first EFI Bighorn Kawasaki to do this anyway! I'm just saying EFI does work.
YZ 250 is running, problems with the injectors being too big so we are waiting for some smaller units.
Injector on times are too small to get the mixture right. Do you know the biggest problem we have here in NZ is getting stuff, no one stocks anything and to order out of the US you have to be sure it's what you want before they send it and trying to ask technical questions over the phone to some parts packer is impossible. Half of them can't even read a ruler, keep telling me sizes in something called " inches " ? 

67

Vintage Two Strokes / NZ VMX Final Rnd

« on: April 22, 2013, 01:15:35 AM »

Yes, New Zealand, just one big MX track. This was an extra good one though. Should be some pictures up soon of the racing. Lucky it was so open and fast for the F9.

68

General Two Stroke Talk / The old Puch

« on: April 20, 2013, 08:53:27 PM »

1.2mm is fine. Too thick will be too heavy, too thin will be too hard to work with.

69

Vintage Two Strokes / NZ VMX Final Rnd

« on: April 20, 2013, 06:09:58 AM »

TMKIWI yes we had a great time, that would have to have been the best ever track! Yes?
The guy winning our class ( pre 75 open ) didn't turn up for the last round so with a left hand track ( right hip replacement imminent ), open smooth and fast it was all on. Three first places ( in class ) meant shifting up the ladder to second place overall, I thought I was turning up to consolidate third. A bit of good luck.  A good result for the first season running EFI in a twostroke. Who said EFI doesn't work in a twostroke.
The YZ 250 EFI is running now also, still needs a bit of tuning on petrol as we used the program straight out of the F9 , runs on ethanol. Injectors also seem to be too big as we are running some small injector on time numbers.
Jeram, I did get a small video camera to strap on for some live footage but it was a cheap chinese and failed before I could use it!! Serves me right for braking my own rules and buying chinese.
I'll get a go pro and be done with it. ( probably still made in china )
TMKIWI it was good to see you there and good to see that bike going so well. 250 next year?

70

Non-Moto / Suzuki EFI 2T

« on: April 18, 2013, 03:27:20 AM »

Isn't a 3L V6 enough

71

General Two Stroke Talk / Trustworthy Piston and Con-rod Brands??

« on: April 17, 2013, 09:13:50 PM »

Put a Hot Rod in it, it's all I use.

72

Non-Moto / Suzuki EFI 2T

« on: April 17, 2013, 09:10:45 PM »

Jeram, why machine out of solid alloy? What's wrong with sand cast heat treated CC601? We have a three cylinder case reed engine here ( for aviation ) but could be made into a bike engine or even doubled up as a V six!!! Imagine that.

73

General Two Stroke Talk / YZ 250 EFI

« on: April 14, 2013, 03:47:35 AM »

Just an update. The bike is back at Blackwood Yamaha ( today ) getting all the bits put back on. By rights it's ready to start! This time I'm running the ignition through the Link computer. This will take a little sorting out ( programing the timing ). Using a 450F flywheel and stator. See the drum throttle valve we cast earlier in this thread.

74

General Two Stroke Talk / KTM 2 stroke fuel injection

« on: April 03, 2013, 08:16:51 PM »

A little back ground, I too hate electronics and for a long time would not have anything to do with EFI. Didn't trust it, didn't understand it and couldn't afford it. Some years ago I helped develop a microlight engine using an EA 81 Subaru block as the base, I ran Mikuni 2x 36 round slides @ $160 each. With the new heads I designed we got 118 HP but being aviation carb icing was a potential problem ( round slides not as affected as butterfly carbs ). We were forced to go EFI. I ended up using the Link system on these engines, now up to 130 HP with a manifold change as well. It took me a long time to come to terms with EFI.
So when caught with a problem on the Bighorn with the engine far too wide, large carb stuck out the side and problems with fueling on E90 I thought perhaps I'll have a go at EFI and get rid of the carb, how hard could it be?? Now I see why It's taken a long time for the twostroke to catch up on EFI, there have been many issues but whats changed is the computers are now so good ( fast ) port injection is now possible. This is a game changer. Yes it's more expensive and yes it's heavier but the gains I think are worth it. The YZ 250 should have a smoother power delivery and by having a larger intake make more power although this is only a byproduct. Power delivery control is what I'm after.
I've got too many projects on the go ( that's why the 250 EFI isn't running yet ) but this weekend we should have the bike finished and ready to start. I'll video it if you like.

75

General Two Stroke Talk / Photo of a 2014 YZ 250 cylinder with EFI?

« on: March 30, 2013, 11:30:44 PM »

Yes not so much as a "black box" but at least a "red herring" . Divert attention away from the trick bits. Some time ago when I was running the Uniflow, we had the engine in a jet boat for load testing. I damaged the gearbox with oil shortage ( gearbox sump not big enough )  so I machined out an extra housing to bolt on, extend the volume. In a hurry at night I grabbed and used a 10 x 1.25 pitch tap for the filler bung. Once I tapped it I could find no bolt to fit in the hole, bugger. So I used a spark plug as a oil tank filler bung.
After that I don't know how many times I was asked what that spark plug was for and why was there on an extra cylinder down by the gearbox, It did make me think that this is a good way of putting people off track, diverting attention, ( if needed ).
No Jeram I'm only interested in a unit for myself and if successful some unit's for others as requested. The Japanese could easily do what I'm doing but they choose not to!