CR Special Crabs on Z1000mkII engine

Hi to all,

I'm new to this forum and I have a Rickman framed Z1000, with a Z1000mkII engine in it fittted with 31mm Keihin CR Special carbs. Engine mods are

1075cc MTC Pistons 10.5:1 from Pit Stop Performance
PSP-3x cams from Pit Stop Performance
Ported head
4-1-2 Campbell x-pipe.

Carb jetting is currently;

Pilot 65
Main 140 (started at 128)

I still need bigger on the mains and the pilot seems to rich, I'm running the standard clip position and the idle screws are at 1 1/4turns out.

Currently belive to rich on the pilot/airscrew, needs to be slightly richer 1/4-3/4,may raise needle as ignition is good but some slight pinging around 4000rpm which can be made to dissapear with snapping the throttle open (accelrator pump), mains still more fuel.

Electonic Ignition system is good will a few ignition curves to choose from, total advance can 34-36deg. Bike is as new fully restored and the engine has 450 miles on it. Does anyone have any experinece with jetting with these sort of mods etc. Plugs are rich. Any advice with Tuning, I have good mecahincal knowledge just not a lot with these carbs. I have already marked throttle positions and checked perfomance etc in each 1/4 of the throttle.

Mainly need to know where people have gone with Pilot jet size, mixture screws and main jets as a guide.

Kindest Regards

John
Perth Western Australia

rickmanoz wrote: Hi to all,

I'm new to this forum and I have a Rickman framed Z1000, with a Z1000mkII engine in it fittted with 31mm Keihin CR Special carbs. Engine mods are

1075cc MTC Pistons 10.5:1 from Pit Stop Performance
PSP-3x cams from Pit Stop Performance
Ported head
4-1-2 Campbell x-pipe.

Carb jetting is currently;

Pilot 65
Main 140 (started at 128)

I still need bigger on the mains and the pilot seems to rich, I'm running the standard clip position and the idle screws are at 1 1/4turns out.

Currently belive to rich on the pilot/airscrew, needs to be slightly richer 1/4-3/4,may raise needle as ignition is good but some slight pinging around 4000rpm which can be made to dissapear with snapping the throttle open (accelrator pump), mains still more fuel.

Electonic Ignition system is good will a few ignition curves to choose from, total advance can 34-36deg. Bike is as new fully restored and the engine has 450 miles on it. Does anyone have any experinece with jetting with these sort of mods etc. Plugs are rich. Any advice with Tuning, I have good mecahincal knowledge just not a lot with these carbs. I have already marked throttle positions and checked perfomance etc in each 1/4 of the throttle.

Mainly need to know where people have gone with Pilot jet size, mixture screws and main jets as a guide.

Kindest Regards

John
Perth Western Australia

Hi John,

Beautiful City you live in. Was there in 06 for a Month.

You're about as sea level as it gets so your jetting is going to be slightly different than what works where I live in the USA.

I think you might be confused on the pilot air screw. You said you're 1 1/4 turns out with a 65 pilot. Then you said you thought you were rich but going to change air screw to 1/4 to 3/4 turns out. That would be making it richer.

Generally, here in the USA, a 65 pilot is plenty for a 1075. It's common to have to lean out the pilots to a 62with 1 turn on the air screw.

The mains also seem large at 140 but you say you need larger....

I've never seen CRS with an accelerator pump. FCR's have one though.

Do you have YY7 or YY8 needles?

Does the bike fire right up, stone cold motor, without needing the enrichener lever lifted?

Hi Larry

Thanks for your info, the section about 1/4-3/4 sorry i was refering to throttle position in saying that it was pinging slightly in this area and needed to be richened up.

Yes the engine will fire up without the enricher no problem and then just hold on the throttle until it warms up a bit.

Neddles are YY8 and I started with 128 mains and have gone up 132, 135 and now 140 and each time it has improved but still feels like it needs more fuel as it will start pulling fine (full throttle roll on) and as the revs rise it will start to hesitate and stumble, wind the throttle off a bit and away it goes again.

Where did you think the mains should be at?

Thanks for the comments about Perth yes I love living here.

Thanks for your help

John

I'm at ~ 1200' elevation, dry climate running CR 29's with a Kerker w/1.5" baffle.
Maybe these will help...

Old Man Rock wrote: I'm at ~ 1200' elevation, dry climate running CR 29's with a Kerker w/1.5" baffle.
Maybe these will help...



Thanks Old Man Rock, this info helps a lot and it is good to see where you ended up, maybe I should try going down to a 62 as Larry suggestedor even 60 pilot and try going the other way with the main jetting, see if I can try some standard 120 mains back in it?

Thanks

John

John, sounds like a real nice set-up you have going.

You may need to try a different timing curve if your getting pinging at 4000. The best way to dial your combo in is with a wideband and a dyno. You have way too much invested in that engine not to get it spot on.
I'd try a YY7 needle in it to get the 1/4-3/4 a bit richer.

We need some pics of this bike!!

I agree with YY7 needles and if you're going to order jets, maybe get some 60 or 62 slow jets. Ideally, you want to have to lift the choke lever just a hair when the motor is stone cold. I'm talking just a finger's pressure on the lever....it ain't much...

You also have air correction jets to work with that are real easy to get at.

Are you running short stacks, long stacks or filters?

Long stacks will put the most mid range in it. Short's will give you the most top end. Filters are the safe compromise for longevity, especially with the sandy environment of Perth. And don't put all your faith in a Dyno. Good to have but they're not the bottom line for optimum performance. What works best there for the biggest HP number on the dyno, sometimes isn't what works best out on the road.

Did you ever play that golf came with the over size clubs? Can't remember the name of the place but it's just outside Perth that has the course like that.

There was a cool place where people hung out at night. A little food stand with a fire pit. You could get hot soup, burgers, etc. I went there a couple of times. We worked our way south along the coast down to Albany, stopping at towns along the way. Went to that pier that goes way out into the Indian Ocean, the light house where the Southern and Indian Oceans meet. Dam near got blown right off the light house cat walk by the wind :woohoo:

Hi Larry and Black Z1R

I will get some smaller pilots ordered and look at the YY7 needles, before I change the needle, could I just lift the current one, after getting the pilots correct?. I have atached a pic of the timing curves I have to choose from in the toal timing range of 34-36deg.I'm running foam hi-flow pods.

Larry I know that places your talking about and they are all good fun, I think the burger place is still runnig, best burgers around for sure. Cape Naturaliste was the lighthouse, always full on wind and very wierd that there is actually a spot where they can pinpoint both oceans meeting.

I would love to get the thing tuned properly on a dyno but this is far eisier said than done in Perth as everyone now just wants to do efi bikes and nothing else.

I will start at the pilots and work my way up etc.

Here is a quick discription of the bike.

Engine: Z1000mkII
1075cc MTC Ceramic Coated Pistons
Andrews Grind 3x Camshafts (PSP-3x)
Ported Cylinder Head, Ceramic Coated including Valves
APE – Cylinder and Main Stud Kits including Main Bearing Brace
APE – Heavy Duty Extra Plate Clutch Kit with Needle Roller Actuator
Ceramic Coated Cases Inside and Out
Keihin CR Special 31mm Carbs with Unifilter Hi-Flow Pods
Ceramic Coated 4-1-2 X-Pipe Exhaust System

Frame: Hand Brazed Reynolds 531 Chrome Moly Tubing
Last Model “Predator” Frame Updates and Braced Swingarm
Re-nickel Plated and Clear Ceramic Coated

Wheels: Ceramic Coated Hubs fitted with Larger Stainless Steel Spokes
Replica Borrani Rims WM3 2.15x18 WM5 3.00x18 Polished and Clear Ceramic Coated
Bridgestone Battlax BT45 Tyres 110/80/18 and 130/80/18

Brakes: Original AP Lockheed Racing Calipers
AP Lockheed Racing Front and Rear Master Cylinders

Suspension: Betor 38mm Forks with Rickman Springs
Ikon 7610 Rear Shocks



Final Drive: 530 Chain 18t Front Sprocket 41t Rear Sprocket

If you reckon you need outside assistance, I can personally vouch for Neil Anderson at Pro Flo. He's somewhere in Perth but buggered if I can remember where. Well worth looking up. Honest and fussy.

What ignition are you running? Looks like the curves from a Moto Witt DMC from the 90s.

Hi Nitro Mick,

Yes I have heard of Neil, not sure where he is at now but will track him down, the igintion is a Sachse Electronica from Germany, very good system, I have two others running on differnt bikes and I think your right about the curves being like moto witt DMC, system is here www.elektronik-sachse.de/index_en.htm check out mounting guidlines for ignition curves etc.

It is so hard to get anyone to help that actually knows what they are on about.

Thanks for your help.

John

I have not used the ignition systems you mentioned.

In addition to proper fuel, 3 adjustments available to aid in curing spark knock are ignition advance, carburetor jetting and intake cam closing value.

Those particular cams shouldn't cause an over abundance of cylinder pressure if the're timed correctly but it's good to understand the concept.

The ignition system seems quite adjustable so I'd start there and leave it at whatever setting makes the knock go away until you get the YY7 needles. Have a good close look at your spark plugs with a magnifier and if there are little specs of aluminum, you're headed for disaster.

You can lift your needles. The air correction jets might be available at a Honda dealer. I can tell you those carburetors are sensitive to exhaust system influence. I've never run one of those particular pipes you have. It may well cause you to have jetting that's different than what you might have with a Kerker or V&H. On my Ninja with 33's, the difference in total throttle response from stock pipes with 33's to a Murray 4/1 was unbelievable. Those 2 components were a match made in heaven on that particular engine.

Can't speak of the fuel in Australia but our pump gas has caused a lot of problems for people these past few years.

Setup correctly it should be a fun ride It's definitely a work of art! Well Done!!!

In case you need...

CR Specials Combined Zip File

Once you get those puppies dialed in, you'll love em...!