Topic: First time at strip with my 750, didn't turn out so good

[cb650]

I would say just work on your launch.  If you see green you lost already.  Get aggressive as you can.  And you have to see what the bike likes best.  Play with shift points.  And jetting unless you had a dyno run.  It takes practice.  It took me a couple years to get the 650 sorted out. 

[754]

Don't change too many things once. Your clutch sounds a bit soft, and you bogged a bit.
 A 17 tooth on the front will help drop your time..

[Lostboy Steve]

I had a 92 mustang notch that was my baby.... but like you mentioned here, Murphys law seemed to come into play every time I ran it. 10.98 was its best time and eventually I had to let it go because it was just "always something", even when everything was brand new. The drag strip is very hard on the wallet.

[Bailgang]

I know my reaction times were pathetic but I was more concerned on how I launched and as good as I thought the engine was running (adrenaline was pumping) the more I think about it it seems as though it was a bit flat on the top end. I had it out a few days before going to the drag strip and it pulled hard all the way to 9 grand+ but didn't seem that way at the strip. The only changes I made was the night before going to the strip I changed my NGK D8EA's for a set of Denso X24ES-U's, I'm thinking of throwing the NGK's back in to see what happens. My carbs behave themselves well on the street but it was obvious they didn't like it when the engine was put under a load so quickly, if I didn't have the revs high enough it would bog but if I revved higher then it would spin a bit, pick the front wheel up about 2 or 3 inches and take off like a scared rabbit but I'd be scrambling to get my feet back on the pegs to get ready for 2nd gear. As far as front sprockets it still has a 630 chain a new one but still a 630 so it's got a 14 tooth front sprocket in at the moment, I normally use a 15 tooth for everyday street riding to cut RPM's down a bit on the highway but put the 14 tooth back in for the strip. I'm really not concerned about reaction times just yet at least not until I get some tuning issues sorted out and get my launch better. One thing I really need to work on is getting my hands in sync with each other as in how I'm twisting the throttle compared to how quickly I'm releasing the clutch. I agree one thing at a time but I'm determined to improve.

[Stev-o]

 One thing I really need to work on is getting my hands in sync with each other as in how I'm twisting the throttle compared to how quickly I'm releasing the clutch.

Once you launch, the throttle needs to remain wide open!

[Bailgang]

 One thing I really need to work on is getting my hands in sync with each other as in how I'm twisting the throttle compared to how quickly I'm releasing the clutch.

Once you launch, the throttle needs to remain wide open!

I was referring to how I'm rolling the throttle compared to how quickly I'm releasing the clutch during the launch itself. I've read so far 2 ways of launching, #1 is to wind it up and let the clutch fly and #2 is to wind the engine up a bit and then quickly (but not let it fly) release the clutch while rolling on the throttle to maintain that RPM as I'm releasing the clutch. There was a lot of unknowns I was dealing with and I need to get used to them so I'm more comfortable and in control of the situation when it happens. I did wind it up to 8 grand and let the clutch fly in one of my runs and the engine didn't bog a bit in fact it spun a bit then took off like a bandit but being it was the first time I did that it caught me by surprise. I knew the bike was taking off hard which is what caught me off guard but it wasn't until I was editing the videos that I saw that during that run the bike had its front tire about 2 inches off the ground when I let the clutch go and even though my wifes camera was at a distance you could still see my eye balls about to pop out of my head. It was also on  that same run that I blew my shift into 2nd gear and floated the valves, as hard as it launched I probably would've had a good ET if I had figured out my shifters position sooner. The pros make it look so easy. 

[Bailgang]

I had a 92 mustang notch that was my baby.... but like you mentioned here, Murphys law seemed to come into play every time I ran it. 10.98 was its best time and eventually I had to let it go because it was just "always something", even when everything was brand new. The drag strip is very hard on the wallet.

I hear you on that which is why I hope I can get my act together as soon as possible to make an improvement and hopefully do it before I break something on the bike. I got the word from my brother with the Mustang and it turns out a bolt had worked itself out were the shifter connects to the linkage so luckily no internal damage was done to the trans. He's a service tech for the company he works for and was supposed to be out of state by Monday so he had the car hauled to the dealership. By the time the car was hauled there and the dealer fixed it his wallet took a $400 hit. Ouch!! I have to admit his Mustang has put up with a lot of abuse, he's had since it was new and it now has a bit over 100k miles on it yet it still runs strong.

[dragracer]

Short wheel base bikes are hard to launch. Rule of thumb, get the rpm's up, and slide the clutch out slowly. Do not throw it away!! Lock throttle as soon as the bike begins to move- but do not throw the clutch away. Slide the clutch out. Repeat this process on launch until you can figure out exactly how quick you can release the clutch without the bike trying to spin or wheelie. The lower the bike, the easier to launch also. Cycle X sells shorty shocks, cheap. You can also pull the fork tubes up in the triples to lower the bike. Get the bike as low as you can without compromising the pipe clearance. This also means getting your body lower in the frame- get an extra seat and have it cut down as much as possible, creating a pocket for yourself as well, so you are locked in and cannot slide backwards. You want your body as far forward as possible over the engine, not over the rear wheel, so pull your nutz up and sit them on the tank-lol. Put your feet forward of the pegs on launch so they naturally swing back to them when you leave. This also put more weight in the front of the bike to keep it down. An air shifter would really help so you wouldn't have to struggle getting your feet on the pegs for the first shift. If leaving with both feet on the ground without the air shifter is a problem for you, i'd suggest putting your left foot on the peg and balancing the bike with the right. This way you are already in the correct position to manually shift the bike. An issue with doing this is the bike will be leaning a little to the right and when you take off, some correction must be made. In order to drop your ET's, you must concentrate on getting the 60' times lower. Only seat time will give you better results. Clutch management is key to lowering the 60'. This once again means- do not throw the clutch lever away- ride it out til the bike gets to moving and then dump it. Be aware at what point dumping it too soon causes the bike to wheelie. Again, you must lock the throttle as soon as the bike starts to move so the rpm's are up enough to avoid the potential to bog. I always tell people, expect to sacrifice at least one clutch pack when learning to drag race a no bar bike. Its just collateral damage in the race game. You aren't trying to save something thats going to help you get better in the long run. 7-8000 rpm launches on a stock motor is not unrealistic but you must learn to control the clutch. Did i say control the clutch again?? Okay, you can count how many times i mentioned controlling the clutch. Lol. That 14 on the front should make it easier to launch the stock motor but it will hurt the top end in the 1/4 mile but you must control the clutch.

[754]

Reaction time does not affect your et at all.
 Check where my stock forks are in my triple tree. I have run them up to about 3 under

[scottly]

Regarding "speed shifting" (without an air shifter), I slightly back off the throttle while simultaneously pulling the clutch lever slightly and shifting. For me this results in fewer missed shifts, as it unloads the dogs when the shifter is operated, and allows them to align in the new position fully before full load is applied. 

[Bailgang]

Did i say control the clutch again?? Okay, you can count how many times i mentioned controlling the clutch. Lol.

If the clutch is the only thing that fails on the bike as I get a launch technique figured out then I'll be happy, it's the original clutch and all I've done to it so far is sand blast the metal plates to put some etch back in them so having to eventually replace it isn't an issue. I didn't bother counting but I understood loud and clear about controlling the clutch and I agree with you. Thanks to all for the great tips.

[Bailgang]

I never was happy with how the carb boot clamps fit so I finally ordered a new set and ordered another valve cover gasket as well because the one that's on it now got torn during the haste at the drag strip last time. I'm in the process of scheduling a date where both my boys, a friend of theirs and myself will go to the drag strip again probably in September sometime, it will be 2 cbr600 f4i's against 2 cb750's. My oldest is just itching to see if his 73 cb750 can outrun mine, I couldn't care less because I'm the one that put his together as well and their friend is itching to see who's got the faster cbr, him or my youngest.

My oldest son couldn't bring his 750 the last time because he never got around to getting his bike license and instead kept getting getting a riders permit, he wanted to get his licenses through an ABATE course but never got around to it and finally this spring his local license branch as they call it here said no more permits until next year or go through the ABATE course, he doesn't have the $300 for the ABATE course so he can't ride on the road this year but we will get his bike to the track this time so he can play with us as well.

[Don R]

Reaction time can affect the ET if the difference is caused by inconsistent staging depth. the only way to know exactly where you are in the beams is to just barely light the stage light. If you roll in deep, the RT goes down but the ET goes up because the vehicle didn't get a run at the light beam.
John force talks about it all the time on TV.

[dragracer]

Scott, any chance you and your family would consider coming to race with us at Valdosta in November??? We're trying to get as many of the SoHC bikes there as possible. It would be nice to make a statement about the old bikes once again. Time moved forward but we're still around.

[Bailgang]

Scott, any chance you and your family would consider coming to race with us at Valdosta in November??? We're trying to get as many of the SoHC bikes there as possible. It would be nice to make a statement about the old bikes once again. Time moved forward but we're still around.

If I had more vacation days available I'd consider it but right now I couldn't do it. Right now the biggest issue with me and the bike is how well I can control the clutch and throttle to get a good solid launch. The other day I removed the new Densos and put my old NGK's back in and it actually seemed to run better so getting the bike tuned as well as I can is another issue because it obviously wasn't tuned as well as I had thought. I'm apprehensive about practicing my launches on the street simply because of safety issues and I really don't like messing around like that on public roads, it's not that I've never ridden my bike aggressively or broken the speed limit on the street but practicing my launches on the street is a bit much for me at least. I know my RT's don't effect my ET's which is why I'm not all that concerned about my RT's at the moment, I'm more concerned about getting a good launch and then making them consistent, once I've got that figured out then I'll focus on RT's. If I can get this bike in the 13's even high 13's would make me happy just so I can shut another brother of mines mouth.