Hidden Valley Drags

[Benz]

Guys,
The Katana did me well on Saturday, well enough to win the event!!
What I thought was the fix for the misfire was wrong all the same. I'm beginning to believe I need leaner carb main jets to clean up it's act.I dropped the needles all the way in, but more than half throttle was still misfire, and it definately runs better when it's cold
The first qualifier had me ready to put it on the trailer, in total disgust. Still stuck in the elevens,and the new mechanical advancer springs didn't seem to do a thing.
But a bit of luck had me three for three in the heats, and my mate who has helped me get this project together won his three, so we faced off in the final, and his clutch master cylinder stuck partially on the line,stuffed his launch, and that was it! Fucken lucky for me, that's all I can say.
There was one photographer there, but he was using film, so there's no pictures yet, but I do have a trophy and a cheque, and a slightly enlarged ego
It's great to actually make money racing, not that I'll retire on 150ozzies!! I could get used to this....

Congrats old chap

[Gix11]

Nice one Benz. I thought you were having a real shit fight with the bike and now you're winning events!(even if there was a smidgen of luck in there). Get that thing sorted and you'll be unstoppable. Get those pictures mate, I'm well keen to see 'em.

[Benz]

Cheers Gix11,
Have no doubts, it has been a year and a half of setup woes with this thing, and it's been just sheer good luck,[and some good reaction times] that have got me this far lately.
I have to be honest and say while there was 20 bikes there on Saturday,[a great turn out for Darwin], the faster 4 guys all had their problems,either breaking down half track, or failing to get to the line. Don't get me wrong, I'm still taking the win!!
I will get some leaner jets in the next coupla weeks, If anybody has CR bits for sale, I want 120's, and 125 mains, the big hex ones,if you got'em..
Gix, I'll work on the pix mate

Talk to me about ya rig? 0412562738

[Nate]

have u replaced the throttle needles and nozles yet

[Benz]

Nate,
No mate, these 37mm CR roundslide carbs were kindly loaned to me to see if they solved the misfire problem!
I had to reset the float levels, and replace the orings around the needle and seats to fix fuel leaks, but I've just moved the mains needles up and down to see if I can get some control over fuel flow. There is no fuel adjustment on the primarys, just a single air/fuel bleed screw.Very touchy, only 1/3 of a turn open at the moment.
They are the third set of carbies to go on this thing.!!
It's at half to full throttle there is too much fuel, so I'm thinking the mains are the problem. Prior to this weekend I would have said 130 mains were not too big, but plugs are black and sooty,
so its gotta be fuel....the ignition is fine, all new.
Why?.....you got some bits?
Are the emulsion tubes and needles bad news on these carbs?They had a clean up, the taper looks consistent , and don't seem to be oval anywhere.In fact they look in great condition, and the bike they were on was a 1327 that ran low 10's, or so the owner said. I didn't personally see it though....no reason to disbelieve him
Maybe the primary jets are too big, I haven't really checked to see if they are actually the size stamped on them, and they may have been drilled out.They are really tight to tune.
Mundy, I'll give you a call when I know more
Cheers

[Benz]

After completlely dissassembling the carbs, I find there is no main air jet , the nozzles do not have any holes drilled[?], Set as they are, there is no fuel passing the main jet/needle setting at idle, the mains are marked 120, the primarys are marked 58.
Am I right to assume these nozzles are for alcohol, does anyone know about these things?
So much for "just put them on, they are set to go!!"I now know never to assume anything.
The more I learn, the less I know!!

[Nate]

i mainly know about trail bikes and yamaha needles and nozels all the time wear out and my fzr1000 had the same simptons and i was talking to head mecahnic from yamaha and he said the same so changed them and it went great
but if u tried other carbs its got me stumped

From memory,or wots left of it! dont CR`s run on the needles only? (no main jet) from my dirt track days the rule of thumb with jet sizes is you "DOUBLE EVERYTHING" when using Methanol.Get ya hands on some of that shit & piont her down the air strip.

PETROL,is for washing parts.
ALCAHOL,is for drinking
NITRO,is for racing!

[Benz]

Hey Mundy,
I contacted the owner of the carbs, his advice was the same as yours basically. I have been running Ultra? , [whatever it is BP98 octane,anyway] from the bowser. The guy said that fuel ran rich when the carbs were on the 1327. So I'm gonna get some racing fuel, BP100, or C12 [20 litres of it,nice to have an Unlimited Drag license] and run with that, 'cause after pulling the carbs down, 120 mains are not to big, and there's really no need for main air jets, when you're not running drilled emulsion tubes. I think no main air jets is messing up the transition from primary to mains though, so I'll simply block off the hole.
Methanol is a really high maintenance fuel, new hoses, rubbers, gaskets, clean the bowls blah blah, every meeting, so I'll just go racing fuel for the moment.
I think I'll probably have to find some bigger needles to ease the topend flow down a bit too, but I've got a few sets to compare here.
CR's have a main jet, and a primary, but no emulsion on the mains, or idle fuel adjustment. I Believe you're thinkin of Lectrons mate, no jets, just set the needles and fly.[8D]
Thanx for the comments mate
Cheers

I got sucess with avgas & 20-30% acetone.Depends on ya comp ratio.if ya plugs are black & mains are not big ya feul is burning too slow.Meth is "thicker" so ya need bigger mians to "draw" it.It also produces condensation,why dont ya run a percentage? & also can ya run "benziene"?
We can buy it down here at the local servo! good luck mate

[Benz]

I have just finished reassembly of the CR's, and found the sliders were set uneven at WFO, but perfect at idle setting. There is wear on the mechanisms that move the sliders, resulting in about a 10% discrepancy across the four,at full throttle.I don't think that is enough to be the reason for the misfire, but it's got to contribute.
So with that tuned out[read bend the arms to suit!], and some racing fuel[or a percentage of it] in the tank, maybe I can get a clean pass in ,no godamned misfire for once.It would be a pleasant change........