2-stage lockup help.

Hi all, i'm trying to dial in my lockup and having some issues, I'm not an asphalt racer but a sand dragger and we only race 300'. The bike is a kz1000j with a 1428 kit, 13.5:1 comp, web 480/460 cams, pinned/welded crank, head was sent to FBG for full race mods/porting, 40mm lectrons and an 80 shot of spray right out of the hole. I have as much weight on the arms of the lockup as I can and .050 shims for the clutch static, I'm running oem clutch springs as well. I had no shims for static to start and the bike shifted 1-2-3 no problem. When I added the .050 shims I noticed the clutch lever was more responsive letting it out and it hit alot harder out of the hole. 1st pass out and it stuttered on the 1-2 shift pretty badly but it did eventually shift, but it had no problems shifting to 3rd. I'm not sure if it's too much wheelspeed or if the clutch pack is too tight. I tried a 2nd gear launch but it bogged really hard out of the hole and I think that may be because I'm a bigger guy and it's time to cut some weight. Gearing on the bike is 14/47.  FBG suggested a 1-2 auto but I don't know if that would be the best idea because things can go sideways fast on the sand and I wouldn't want to bend shift forks if I had to backout of it. And yes the bike does have an MRE airshift that gets charged to 125 psi. Even after all that we still struggled to a 3rd place for the last race of the season. Any help would be greatly appreciated!

Welcome to KZRider
Interesting rig. 
Can't  really give you  set up advice  for best combination  for launch 
But  if more weight is needed on lockup maybe use different nuts / weights  to increase pressure ( lead on bolt secured by nuts )
Never had to on my lock up but sand is different 
Have you considered different tires ???    My son would change to different paddle designs and  tire heights on sand bike for best launch and climb 
Also next time you post pictures please click the insert all tab to complete picture install so they will be full size 
I fixed it for you this time
Dave

What is the overall weight? (vehicle plus rider w gear)

Weight and tire combo were always the important factors in setting up a lock up for drag race use on asphalt, would make sense to start there with sand. Only limiting factor is how much slip or traction there is. Gearing only comes into play for different race lengths (1/8 vs 1/4 mile etc.)

You also need to know the installed height spring pressure on the springs your running in the clutch. Total static weight in clutch depends on the overall weight of the vehicle and rider.
Stock clutch springs are usually too heavy to be used in these clutches (under most circumstances) most drag guys use lighter springs. Having a spring pressure checker becomes important.
You also need to know at what RPM your launching - you never mentioned that. To get consistent results you need to be on a two step rev limiter - you never mentioned that either.
You can find the instructions for the multi stage lockup on the MTC web site, a lot of the above mentioned is on there but its not much different that a single stage unit (old MTC/MRE) you should give them a call, they could probably help you out once you give them some info (overall weight/static/usage) either way its going to take at least 4-6 passes to figure it out.

This should have been put in the racing section.
 

I'm fairly sure the clutch is locking up, I've checked the steel's in the clutch and there isn't any bluing or warping. It launches great with the heavier static only reason I went with more static is to try and bring the 60' time down which it did but only slightly. 1.650 60' with no static and a 1.550 with .050 shims. I've tried smaller paddles with a lesser paddle count and it shook the tires very hard. I guess I should've worded it better but I'm mainly having trouble on the 1-2 shift (not trying to sound sarcastic but sometimes things can be interpreted differently over text). It had no problems doing the 1-2 shift with no static shims but now after adding shims it stutters on the shift and eventually does shift. Thanks for the advice on the pics, it's the first time I've created a thread so I will do that next time. I've got a couple videos on my phone but when I tried to add them it said it didn't support an mp4 file. 

Overall weight for the bike and myself on-board is around 750 lbs. I'll have to check the height as well as spring pressure when I get home from the jobsite. Who makes a lighter spring? I've seen springs that are heavy duty but haven't seen any that are softer. I do have a 2-step installed and it slipped my mind to include that info, we're launching at 8500, shifting at 9k and top limiter is set to 11k. I'll give mtc a call at lunchtime tommorow and give them the info too, so far all the ETs have been fairly consistent running 4.0s @85 it's only differed maybe .02 up but never broke into the 3s. It did lose mph with the static change but didn't lose or gain ET, that being said we never got a clean run that weekend with the shifting issue so it may go quicker. The chassis was built in the early 2000s and had an old kz900 in it with a 1200 kit and 60 shot and has been 3.4s with a 120lb lighter rider but they never had problems shifting it so i wasn't sure if it was a weight problem or a clutching/lockup issue. I'll keep in mind the category issue if I create another thread, thank you for letting me know that. 

who's lock up kit MTC ? MRE ? if so contact them When I drag raced I used just enough weight to lock up clutch till very end of 1/4 mile , you only use just enough weight other wise you are defeating purpose of lock up.

Your MRE air shifter 
Is the ignition kill setup  to help the trans unload during the shift.??
Is the system all air or electric over air ??
Havent had one in a long time  so just trying to get current
Dave
 

wrote:

Overall weight for the bike and myself on-board is around 750 lbs. I'll have to check the height as well as spring pressure when I get home from the jobsite. Who makes a lighter spring? I've seen springs that are heavy duty but haven't seen any that are softer. I do have a 2-step installed and it slipped my mind to include that info, we're launching at 8500, shifting at 9k and top limiter is set to 11k. I'll give mtc a call at lunchtime tommorow and give them the info too, so far all the ETs have been fairly consistent running 4.0s @85 it's only differed maybe .02 up but never broke into the 3s. It did lose mph with the static change but didn't lose or gain ET, that being said we never got a clean run that weekend with the shifting issue so it may go quicker. The chassis was built in the early 2000s and had an old kz900 in it with a 1200 kit and 60 shot and has been 3.4s with a 120lb lighter rider but they never had problems shifting it so i wasn't sure if it was a weight problem or a clutching/lockup issue. I'll keep in mind the category issue if I create another thread, thank you for letting me know that. 




 

For lighter clutch spring there are a few options, MTC sell springs listed on the web site under "lock up clutch components" listed as multi stage spring kits $36
You could also cut the spacers on the hat to reduce the installed spring pressure (that's what I did on my MRE unit) to get a lighter static you can also eliminate springs and run 3 or 4 instead of 5 to get the weight down.
On asphalt with that weigh and motor combo I would launch around 7000, shift at 9000-9500 and set the rev limit at 10,000-10,500 Launching at high RPMS is for smaller motors, you don't have to kill it when your over 1400 cc. For static spring pressure you would want to be around 180 lbs to start. If your using stock springs your probably around 220 lbs or more for 5 springs.
Again these numbers would be a starting point for asphalt racing.
Usually it's best to start with lighter springs, then use shims to adjust your static.
It may be in your best interest to call them for advice specifically targeted at dirt racing, they probably have sorted out dirt dragers in the past and will give you the setup for you combo.

The following info is from the MTC web site specifically for the 2 stage lock up :

If your bike is too aggressive, then you need to reduce the amount of static spring pressure. If you have shimmed the springs, then you need to remove some of them to reduce the pressure. If your springs are not shimmed then you need to get some softer springs. The launch of a lockup equipped bike is totally controlled by the clutch springs. Your lockup does not start to apply until the bike is in motion, usually about 10-20ft off the line depending on the type of lockup you have. MTC stocks softer clutch springs for a number of applications, so give us a call.

If your bike is lazy or is driving through the clutch at launch, then hooking up about 20 feet off the line, you need to increase your static spring pressure. You need to add shims to the tops of the clutch springs. We suggest putting the shims on the top so they can easily accessed if you need to lower the spring pressure. As a general rule, the .025" shims will add 1-2 pounds of pressure per shim per spring. The .050" shims add between 2 and 3 pounds of spring pressure per shim per spring.

What will happen if I pull the clutch lever at high speed/RPM?   You should avoid this if at all possible, if the lockup is fully engaged you may not be able to pull the clutch lever and attempting to do so could damage internal clutch system parts.

adding weight to the arms steepens the curve of clamping force. If the weight remains the same changing the springs will move the curve higher or lower in the RPM band however the clamping slope will remain the same. This is one of the reasons we recommend keeping the weight the same on each arm. If you are just trying to change the RPM of the arm application do it with the springs. The need for more clamping force would be dealt with by adding weight.

Reducing the arm weight on a 2-stage will not really change the timing, just the overall force it can generate. The arms on a 2-stage lockup will apply at the same time no matter how much or little weight is on the arms. Removing weight reduces the amount of overall clamping force the lockup can generate which may cure an aggressive condition on the bottom end but could also lead to it driving through the clutch on the top end.

MTC recommends there be .100-.125" clearance between the flat surface of the arms and the hardened steel buttons in the pressure plate.
Having too little clearance can result in the arms not  be able to swing out far enough to generate sufficient leverage to lock the clutch up.
Too much clearance especially on a multistage lockup results in the arm reaching its travel limit before applying enough force to lock up the clutch pack.
The .125" max is not as critical on the 2-stage lockup since these arms are capable of more travel than the multistage. In order to measure this clearance on a two stage lockup you will have to hold the arm in position.