CR Special Crabs on Z1000mkII engine

Thanks Larry,

yeh it turns heads alright and gets some looks, I had never entered a bike show before and two weeks after finishing it I entered it in the Jap Bike show in Perth and it took out the Z-bikes open class, in was stoked but not as much as when a 76 year old gentleman (Jim Thomas)came up to admire (said I almost got the colour perfect) the bike and said he actually sold these brand new in 1975 at the Allron dealership in Perth and raced one back in the day, we talked for ages and his mate who was about 10 and a bit yrs younger raced a Z in the 70's and had raced a lot of famous endurance races in Australia such as the Castrol 6 hr etc. They also spoke about racing the BMW R100 bikes as well and Jim said he used to make his riders do 10,000kms on the BM's on the road prior to racing them so they were run in, he gave them around a week to do this. He road his bike to the show and was a bit hunched over and told me he had just had his spine fused two weeks prior. Amazing guy and I'm really glad I went to the show after all, the trophy was a nice recognition of my work but the conversation with these two guys was pure gold..

I will aim for your main jet readings when we get to the dyno.

Talk soon.

John

76 and still riding

Congrats on the trophy!

Wow, love the rickman bikes, that is beautiful.

Hi to all,

Well i have been having fun with the bike, I bought an Innovate Motorsport LM-2 wideband A/F tuner and have been playing. It has been great to see what changes affect the A/F at what thottle points and I'm glad to have invested in my education via the tool. I do have one problem with it though as it seems to suffer badly from electrical noise and keeps resetting itself etc (not a power issue as even used and external battery pack), fine when away from the bike, I'm running Dyna mini coils and straight copper core leads with NGK 5kohm caps and non-resitor plugs. I'm going to try the resistor type plugs to see if it will cure it. Anyone else used one of these and had the same issue?

The run 3rd gear roll on below is with the #62, YY7, #110 the bottom axis is time in seconds, left is AF (yet to get it to log rpm as well) as can be seen through 1/4 throttle rich around 10.2, half through midrange lean around 14.5 and then the main jet dips down to as low as 8.8

Have now changed to #60 pilot, YY8 needle, #110 main. Needs a bit more fuel midrange so will be adjusting the needle clip one spot and try again.

Anyway thought you might like to see my progress and I'm having fun doing it.

Hi to all,

Well i finally got the bike on a dyno and it was a worthwhile exercise. The bike performed well and put out 112hp and 66ft/lb of torque. We ran it under load at 1/4, 1/2 and 3/4 throttle and all of the fuel settings were sorted out (all around the 12.5-13). Had to go up on the main jet and up on the needle clip position. Stared at 103hp and went to 112hp. The only anomally was around the 5-6500rpm when it gets rich and drops HP and then takes off again (we eventualy ran out of time). I'm yet to ride the bike on the road again as yet as the run was only yesterday. Can anyone offer any suggestions, i'm not running the supplied bellmouths but Unifilter foam pods, could this have anything to do with it? any help would be great. Thank in advance.

What cams are in it?

What are the lob centers?

How big is the motor?

Ride it on the road. See how it performs there. Pay attention to how quickly you roll on the throttle. See how much that causes it to stumble. In other words, it may not be severe if the throttle is rolled on slowly vs yanking it full open.

Do you have any air correction jets?

The stacks supplied with the carbs should make it run best but that's not a good street setup. However, you might try them for a run or two down the road before you dive real deep into other tuning aspects. Do it the same way...pay attention to how quickly you open the throttle.

Do that in 2nd and 3rd gear.

Hi Larry

1075 CC MTC Pistons 10.5:1 compression
PSP-3x Cams just reset to 106 lobe centers, .418 lift, 282Deg.

I will run it on the road, today I have managed to get the bellmouths on the bike and the Unifilter pods over the outside of them. I will check how it rides with rolling on the throttle as it was fine with rolling on the throttle smoothly (previously on the road)on the dyno just when it was quickly opened it always fell over at 3/4 throttle and then took off again. Air jets are 240 in the carbs now and I don't have any others at this time.

Any thoughts? and i will let you know how it rides.

Regards

John

Hi to all,

Well I have finally got the bike very close and it rides great, #62 pilot 1 turn out, YY8 needles No 5 clip, 115 main jet, 250 airjet and refitted the velocity stacks inside the unifilters which got rid of the dreaded 6-6500 dip. Ignition set on No 5 advance curve which gives a total 34deg and gets rid of the half throttle point pinging. The bike rides so smoothly now with transitions in all areas very smooth, another ride to see if I need to shift the needle back up to pos 4 clip and we are done. On the dyno it put out good horse power prior to the refitting of the velocity stacks and the bigger airjet but still didn't ride 100% well now it does.

Thanks to all those that have helped out with advice and info.

Regards

John

I had a huge problem years ago trying to tune a set of Crs. I ended up changing the jet needle to a leaner one and went down on the mains... Anyway One day I decided to check the float heights and realized they were set too High too lean and once I set them to the correct height everything else was effected and in the end I ended up putting the original needle in and jetted it back up. Having said that I have found that these carbs are usually jetted on the rich side and likely you would not need to go above 125 main.