CB72/77 Race Ignition and Cams

[jensen]

Hi,

Hi Jensen,
Thanks for the tip. Is this your bike? If so, how do you like it? I didn't see any pricing on their site, about how much was it?
Thanks,
-Gabe

q1 : No, not yet ?

q2 : very stable and powerful spark, timing is very precise

q3 : don't know

Jensen

[gltrench]

Thanks for the replies everyone. My motor is going to be pretty stock. I'll only be doing track days and one or two AHRMA events a year, so reliability is my goal. Maybe I'll just stick with stock cams for now.

Here's what I'm planning on doing with my motor, I welcome any advice or critiques.
-Hi-Comp pistons (don't know the ratio, but they're much taller than stock-ebay find).
-26mm 305 carbs
-Electrex Stator Ignition
-Swarbrick Megaphones
-Light porting (primarily intake to match bigger carbs)
-HD valve springs/ti holders/keepers (les' Advantage)

Any comments out there? Will the stock rockers and cams surive the HD valve springs?

I'll admit it, I don't have much experience with building racing four-stroke motors.
Thanks!
-Gabe

[LOUD MOUSE]

Have ya raced GP bikes?. ....................lm

Thanks for the replies everyone. My motor is going to be pretty stock. I'll only be doing track days and one or two AHRMA events a year, so reliability is my goal. Maybe I'll just stick with stock cams for now.

Here's what I'm planning on doing with my motor, I welcome any advice or critiques.
-Hi-Comp pistons (don't know the ratio, but they're much taller than stock-ebay find).
-26mm 305 carbs
-Electrex Stator Ignition
-Swarbrick Megaphones
-Light porting (primarily intake to match bigger carbs)
-HD valve springs/ti holders/keepers (les' Advantage)

Any comments out there? Will the stock rockers and cams surive the HD valve springs?

I'll admit it, I don't have much experience with building racing four-stroke motors.
Thanks!
-Gabe

[gltrench]

Have ya raced GP bikes?. ....................lm

Hi LM,
I'd hardly call my Honda NT650 Hawk a GP bike! That thing is a bit of a toad. So, I suppose the answer would be no. I also have been racing supermoto on a CRF450. I've stayed away from vintage racing since there aren't very many opportunites to vintage road race here in Southern California, only a couple a year. Since having kids a few years ago, I now realize that riding a couple of times a year sounds about just right!! I guess it's time to go vintage.
-Gabe

[LOUD MOUSE]

I ask cause there is a lot of fun/excitement racing any sort of bike.
That said were I to return to racing I'd build a cost effective machine.
Simple/safe/dependable/no faster than I can have fun with. .............lm

Have ya raced GP bikes?. ....................lm

Hi LM,
I'd hardly call my Honda NT650 Hawk a GP bike! That thing is a bit of a toad. So, I suppose the answer would be no. I also have been racing supermoto on a CRF450. I've stayed away from vintage racing since there aren't very many opportunites to vintage road race here in Southern California, only a couple a year. Since having kids a few years ago, I now realize that riding a couple of times a year sounds about just right!! I guess it's time to go vintage.
-Gabe

[305racer]

Thanks for the replies everyone. My motor is going to be pretty stock. I'll only be doing track days and one or two AHRMA events a year, so reliability is my goal. Maybe I'll just stick with stock cams for now.

Here's what I'm planning on doing with my motor, I welcome any advice or critiques.
-Hi-Comp pistons (don't know the ratio, but they're much taller than stock-ebay find).
-26mm 305 carbs
-Electrex Stator Ignition
-Swarbrick Megaphones
-Light porting (primarily intake to match bigger carbs)
-HD valve springs/ti holders/keepers (les' Advantage)

Any comments out there? Will the stock rockers and cams surive the HD valve springs?

I'll admit it, I don't have much experience with building racing four-stroke motors.
Thanks!
-Gabe

With the exception of the Swarbrick megs Les Barker @ Vintage Advantage out in Washington state has everything you listed above and more including knowledge of these bikes no matter what stage you want to take it to. He is a neat guy to chat with and even tried talking me outta having any work done on my engine in favour of buying a 5speed. lol
The Swarbrick megs come in 2 different lengths and neither direct copies of the CYB part nor do they come with hangers. You have to make/weld your own.
If you are in SoCal try looking up Tim Mings,he is a respected/winning Superhawk racer in the LA area. His philosophy is a little different than Mr. Barker's, prefers a shit hot motor and a 4speed. lol

[gltrench]

With the exception of the Swarbrick megs Les Barker @ Vintage Advantage out in Washington state has everything you listed above and more including knowledge of these bikes no matter what stage you want to take it to. He is a neat guy to chat with and even tried talking me outta having any work done on my engine in favour of buying a 5speed. lol
The Swarbrick megs come in 2 different lengths and neither direct copies of the CYB part nor do they come with hangers. You have to make/weld your own.
If you are in SoCal try looking up Tim Mings,he is a respected/winning Superhawk racer in the LA area. His philosophy is a little different than Mr. Barker's, prefers a shit hot motor and a 4speed. lol

Hi 305racer,

I bought the Yetman frame from Tim. He seems to be the 305 racing guru, but also plays his cards close to his chest! Several years ago I spoke to him at an AHRMA event as he lit up his CYB kitted 305. The bike sounded amazing, unlike any Honda twin I have ever heard. I asked him what he had done with the motor. His reply, "It's pretty much stock." Hmmm......I'll have to prod him a bit more for some 305 wisdom.

I'll definitely be giving Les Barker my business, I hear he's a good guy.

By the way, If the Swarbrick exhaust's are simply megaphone blanks, are there any shops here in the States I can give my business to? I have a set of CYB exhaust on my CYB-72 kitted bike (for show, not go) that I can measure...maybe Circle F?

Thanks for the tips!
-Gabe