Topic: Doing the HSTA TWISTAR ride wonder what the welcome will be for the 750?

[ElCheapo]

I just jumped on the wagon with the TWINSTAR sport touring association. I will be going to the ride at the Voyager. Seeing that this "club" is mostly sport bikes I have to wonder if they will understand the whole big CC sport bike movement started with the CB 750? We will see. The ride they will be doing is one I do all the time.

It is a nasty twisty run and too say the least you have to be in the mood for it. This is the strech of two lane twisties that wind through Wildcat Mountain near by. I think I will just pace it out. I figure sticking in the middle of the pack will make a statement enough for the 750.

Won't they freak out when they realize it is not a 750 anymore? With Battleaxe tires and over 1100cc's to get the job done I think I won't have a hard time getting respect for the vintage girl. It is definitely a wolf in sheeps clothing, just like I wanted it to be. I originally wanted her as stock looking as possible but as nasty as nasty will allow and still be reliable.

I'll let you guys know how this goes.

[ProTeal55]

Do it !

I have seen riding my CB around, the newer crotch-rocket riders look down on my bike, because it
isn't a new plastic fantastic bike. I usually just do a burnout next to them until their girlfriend on the back starts coughing (makes me feel good) 

Let us know how it goes......

[dusterdude]

give em hell!!!

[eldar]

I would like to know what you did to your motor to get those cc!

[dusterdude]

I would like to know what you did to your motor to get those cc!

yea,me too.

[ElCheapo]

First off I did say I never devulge the how but, here we go  .

This is a bit of hardcore machining and sci fi built into the same machine. This mod was borrowed from some old schoolers and the Satanic Mechanic site. This is a motor that I have been working on all winter in secret for the most part. Now that I have the new motor in the bike I figure now is a good time to tell.

DO TAKE THE TIME TO NOTICE MY BIKE IS A SPOKER - SO THERE ARE NO - I REPEAT NO HOLE SHOTS unless I want a collapsed rear rim. This is how I snapped a few spokes already .

I will leave a few bits of mystery, you decide if this is an F or K motor.

First - we trick out the head because this monster has to BREATHE. It gets larger valves and a swirl port job. For the most part the rest stays stock until we mill the head a bit.

Second - CB 900 DOHC Crank This requires extreme machining to make the fit into the SOHC case. As well as fitting issues for the cam chain.

Third - We do the most insane big bore punch out at 73.00mm. Any more and simply would not work. All of the gaskets for this application are special. In many places gaskets have been replaced for O-rings set into a machined grove. Because of the air space between the cylinders is near non-existent I have no idea how she will respond to longer runs as far as heat goes.

Stock oil pump ditched and set up with hidden electronic pump that is fully adjustable. This is equipped with a fail safe auto shut down in the event the oil pressure drops below 30 PSI.

The front spocket area gets a custom made steel shield as well as the drive chain getting a spring loaded guide roller to keep chain snap damage to a minimum. In the event of a chain snap it keeps the drive chain trapped between the sprocket and roller

The O.E. HM 300 pipes were to restrictive so we pulled the baffles out completely. It is rather free flowing and has a rather nasty note.

The cam shaft is a custom regrind with enough duration that she does not idle the greatest but has power through the entire range. I was talking with a buddy and he assures me we could leave the stock carbs on the bike, disable the carbs completely, and install a fuel injection system from a Kawasaki Z1 Classic that would work. By using the fuel injection with a mass airflow sensor we can kill the idle lope altogether and have the same power - so she will idle like stock at the lights. Then it will be time for a fuel pump that can keep up.

And last but not least the carbs are O.E. but have been opened up to make it possible to get all the right fuel to her.

For Reference

Bore (mm) Displacement (cc) @ stock stroke
61.00 - (stock) 736
61.25 - (1st oversize) 742
61.50 - (2nd oversize) 749
61.75 - (3rd oversize) 755
62.00 - (4th oversize) 761
 
64.00 - 812
64.50 - 823
65.00 - 836
 
67.00 - 895
67.50 - 915
70.00 - 970
73.00 - 1060

Because we are in the first 100 miles of breaking in I have no idea what she will put out for HP on the dyno, but I can tell you she is nasty. When rolling at about 25 in tight traffic, I nail her open and she takes off matrix style at at near triple frame rate. It looks sureal. I have to brace and fight to stay on her  . Could she be one of the fastest O.E. looking CB 750's in the world? Maybe. Crotch Rockets only get one view of my bike now - the rear.

Sorry you took the red pill now huh?

[dusterdude]

dayum!!!!!

[ElCheapo]

Just sick huh
 

[dusterdude]

hell yea,i get a woodie just thinkin about it.

[ElCheapo]

I figured I would just build it on two words "No Rules" or is it more like "No Fear" 

[dusterdude]

either way,she`s gonna be nasty.

[eldar]

OK that would be too much for me to do! I would have to have someone do an engine like that for me!

[ProTeal55]

Whats the expected lifespan/reliability on something like that ??

[ElCheapo]

Whats the expected lifespan/reliability on something like that ??

As long as I dont seriously overheat it it should have the same reliability of the original I think.

[ProTeal55]

Got a Heavy Duty oil cooler on that thing ??

[ElCheapo]

It is the one thing I am lacking. I was thinking of using a CB 900 cooler. Should hide ok and not be a big deal.

[ProTeal55]

It is the one thing I am lacking. I was thinking of using a CB 900 cooler. Should hide ok and not be a big deal.

Be creative and run some oil lines thru the frame. The longer the oil is outta the motor, the cooler it will be. Crap, just run the oil IN the frame and screw it all .

[dusterdude]

hell yea,now yer talkin

[ElCheapo]

It is the one thing I am lacking. I was thinking of using a CB 900 cooler. Should hide ok and not be a big deal.

Crap, just run the oil IN the frame and screw it all .

Now that is getting weird...I am not weird, just offensive...

[eldar]

Oil in the frame leave even MORE areas where leaks can spring up! Imagine having a hole somewhere in your frame and trying to track that down!

[ElCheapo]

OCC puts air, oil, and gas in frame tubes, not me thank you.

[eldar]

Yeah well occ dont even know how to make bikes. they just put pieces together.

[my78k]

Curiosity forces me to ask about the stock frame...any major mods to handle the extra power? Would be concerned about the torque on this wouldn't we?

Dennis

[ElCheapo]

The stock frame is kick ass. These frames handle more than you can believe. I mean its not like I made a 1000 hp drag machine. I think the HP will be somewhere in the realm of 100-120HP. My luck is that it is most likely a little bit lower, but with the power to weight ratio being what it is, the bike is fairly light and very fast.

[Jerry Rxman Griffin aka MuthaF'er]

Sweeeet. Where did you find the seat belt?

2 things -

First I heard that OCC has possibly commissioned a certain company in far northern Wisconsin (?) to build a 750 engine. The crank is supposedly being produced by an old TQ guy in Indiana for that company in Wisconsin. I will mention no names. We'll have to see if this #$%* ever happens.

Second - Anyone seen the used 1080 kit on EBay ??  Better get to it fast. There may even be 2.