Author Topic: Cobra motor disassembly and rebuild (Read 107741 times)

dragracer · « **Reply #475 on:** July 11, 2016, 07:55:02 AM »

Quote from: POPS 911 on July 10, 2016, 08:43:20 AM

Frank got two batteries I think, and Bill with a big cut on his head and special pistons he might need two and your right leg will take a beating self starting a ST/ET SOHC 750. Looks to me like the Blinkster [ BLINKSTAR ] will be the new number for SEL ................. 10 flat.

Pops, my F model is kick start only. You might be thinking about my Crazy 8’s KZ. It’s a 1325, 13.5:1 engine so I had to have 24 volts to crank it up.

In respect to my F model, it’s somewhat crossbred in the fact that the pistons are for a K model but the head is an F2 head with the larger combustion chamber. In essence, the pistons do not fill the chamber like Bill’s 1080 since he has a matched K head and piston set. Think of it as putting a J model head on top of a set of KZ pistons. The J model head has a large combustion chamber, but even high compression KZ pistons won’t fill the chamber enough to get the compression up. Even by milling the head to get to closer to the KZ pistons, it won’t help to optimize the better flowing head until you get the right pistons to match the chamber. That’s the scenario I’m working from on my current package. Bottom line, Bill’s matched parts should net much more compression and a lot more horsepower and torque than my engine. As a result, his engine should be capable of 10.0’s. The dilemma is, the total package including bike has to be set up correctly to put that power down on the drag strip. In addition, the rider has to be able to fully utilize the overall package to produce a low ten second time slip. I don’t feel this engine will get into the 9’s without being placed into a properly set up wheelie bar bike chassis- unless you put a 120lb experienced rider in the seat.

POPS 911 · « **Reply #476 on:** July 11, 2016, 10:21:00 AM »

Tuning lesson this past weekend : Racer has a 1150 base Suzuki motor, lockup and a air trans brake = run 9.40...... I st. pass he went nowhere and pulled thru the lights on the 2 step and I asked did you touch anything since last race

Yes in his hopes to go faster he add a spring to the clutch and with a 7000 chip in the two step it pulled thru the line lock. My fix to him why 7000 chip for two step = seems high, put in a 5500 chip two step and a 10,000 rpm auto shift up from 9500 and he ran 9.16 and the best 1.2 60ft time he ever had in 1320 and this guy is a wrench spinner. Lesson learned in drag racing motorcycles is balance....... he complained about MPH NOT AS HIGH and I ask him do the pay for MPH or WIN TICKETS !!!!!

dragracer · « **Reply #477 on:** July 11, 2016, 12:55:45 PM »

Quote from: POPS 911 on July 11, 2016, 10:21:00 AM

Tuning lesson this past weekend : Racer has a 1150 base Suzuki motor, lockup and a air trans brake = run 9.40...... I st. pass he went nowhere and pulled thru the lights on the 2 step and I asked did you touch anything since last race Yes in his hopes to go faster he add a spring to the clutch and with a 7000 chip in the two step it pulled thru the line lock. My fix to him why 7000 chip for two step = seems high, put in a 5500 chip two step and a 10,000 rpm auto shift up from 9500 and he ran 9.16 and the best 1.2 60ft time he ever had in 1320 and this guy is a wrench spinner. Lesson learned in drag racing motorcycles is balance....... he complained about MPH NOT AS HIGH and I ask him do the pay for MPH or WIN TICKETS !!!!!

No doubt that proper tuning is important on a bar bike. Leaving harder doesn't always net the best results as I learned a long time ago.

So true about the MPH. I see so many people get caught up in that number its crazy. When I see high mph, it usually indicates a crappy short time. That's why when my mph increased this season I paid close attention to my time slips and sure enough, my 60' and 660' times dropped off.

POPS 911 · « **Reply #478 on:** July 13, 2016, 04:07:27 PM »

Bill: How did the dyno pulls go this past Friday with [ PACE or RC COBRA head ] ? Their is a guy who has a HARLEY shop near my home with a DYNO he has not used in the past so I will stop by his shop and ask if he wants to pass it on for a fair price [ I mean a low price ] could be a tool for you to learn to run and tune your many race bikes. In the PRO-STAR days MSP brought their own dyno in the big double stack trailer and made cash dollars night and day. I would like to see your Yellow turbo Hondamatic SOHC750 make passes in 2016.......

Jerry Rxman Griffin aka MuthaF'er · « **Reply #479 on:** July 13, 2016, 06:01:22 PM »

BAMMMMMM. Exactly the addition Billy needs!!

Bill/BentON Racing · « **Reply #480 on:** July 13, 2016, 06:31:10 PM »

POP'S, sounds good, waiting for a dyno date this week.Let me know on your buddies dyno, thanks, Bill

Medyo Bastos · « **Reply #481 on:** July 13, 2016, 07:42:50 PM »

yeah, you can keep it at my place

kmb69 · « **Reply #482 on:** July 13, 2016, 08:47:48 PM »

Quote from: Medyo Bastos on June 19, 2016, 11:55:22 AM

BBQ is on me at interstate one night that weekend

Dammit! Up to my nose in gators.

Looking like I'm gonna miss that BBQ I was counting on. $:-\$

Medyo Bastos · « **Reply #483 on:** July 14, 2016, 03:04:07 PM »

Quote from: kmb69 on July 13, 2016, 08:47:48 PM

Quote from: Medyo Bastos on June 19, 2016, 11:55:22 AM
BBQ is on me at interstate one night that weekend

Dammit! Up to my nose in gators.
Looking like I'm gonna miss that BBQ I was counting on. $:-\$

we'll send you a doggie bag

kmb69 · « **Reply #484 on:** July 14, 2016, 07:05:38 PM »

Quote from: Medyo Bastos on July 14, 2016, 03:04:07 PM

.....
we'll send you a doggie bag

Hey thanks! You got my address!

POPS 911 · « **Reply #485 on:** July 16, 2016, 09:58:26 AM »

Bill: Remember to leak down that motor after the dyno pulls, you do not want to find a problem when you get to Memphis........ your parts will be home in Georgia.

Bill/BentON Racing · « **Reply #486 on:** July 16, 2016, 01:05:45 PM »

Yep, I will. See ya next week, Bill Working on z back up ride, making it a real drag bike also, well, my opinion, lol, Bill

Jerry Rxman Griffin aka MuthaF'er · « **Reply #487 on:** July 16, 2016, 02:42:47 PM »

Well that LIGHTWEIGHT tach should drop you at LEAST a tenth!!

dragracer · « **Reply #488 on:** July 19, 2016, 12:04:12 PM »

Are we ready Bill??

I've still got to finish the maintenance to my Honda then work on 2 other bikes. If I don't get my bike straightened out, can I borrow Purple Rain??

Bill/BentON Racing · « **Reply #489 on:** July 19, 2016, 02:31:14 PM »

Haha, of course you can. Of course I gotta finish it too! Lol.

dragracer · « **Reply #490 on:** July 22, 2016, 05:01:47 AM »

Hmmm, can we assume that you never made it to the dyno?? Or are you withholding other news???

See you this evening. Getting a late start after a long night of tying up loose ends that are still somewhat unraveled. Thrashing will be going on in my pit area tonight.

Bill/BentON Racing · « **Reply #491 on:** July 22, 2016, 10:18:05 AM »

No practice. No dyno! But we think we ready. 3 hrs sleep over last 2 nights. Lol. Trailer took a lot,damn was it hot! Just saw Ratbike Mike at the gas station. Wilbur's there by now, K. More later, woke up yesterday morning to my 14 year old cat had passed overnight. Oh well, let's go racing. Bill

Sam Green Racing · « **Reply #492 on:** July 23, 2016, 09:39:57 AM »

Live from Memphis via the UK. Looks Like Bill ran a quick time but no details available in trials, looks like he missed 1st round.
Frank pulled a red in first round and broke out anyway, Trey also pulled a red.
All should be out in the next round.

Sam. listening live on facebook.

kmb69 · « **Reply #493 on:** July 23, 2016, 10:12:07 AM »

Quote from: Sam Green Racing on July 23, 2016, 09:39:57 AM

.....
Sam. listening live on facebook.

Thanks much for the updates Sam.
Where are you getting this on FaceBook?

Sam Green Racing · « **Reply #494 on:** July 23, 2016, 10:14:22 AM »

I'll share it to your status.

Sam Green Racing · « **Reply #495 on:** July 23, 2016, 10:16:08 AM »

Done Keith, should be on your page.

kmb69 · « **Reply #496 on:** July 23, 2016, 10:22:21 AM »

Got it. Thank you Sam.

madmtnmotors · « **Reply #497 on:** July 23, 2016, 10:31:28 AM »

Somehow I managed a first round bye. Not sure how, must have been a random draw. Tried to trade it for a round two bye but that was not an option, dammit!

madmtnmotors · « **Reply #498 on:** July 23, 2016, 10:36:08 AM »

Maybe they felt sorry for me after the tie down strap broke on the way up...

Jerry Rxman Griffin aka MuthaF'er · « **Reply #499 on:** July 23, 2016, 10:44:37 AM »

Ouch!

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Author Topic: Cobra motor disassembly and rebuild (Read 107741 times)