cb750 slow take off

[surffly]

Stock they bikes don't have an instant power pick up mid RPM.
Hard to tell if you are just not used to how the bike should feel or if you have a real issue.

I will say that the pods, even if an attempt to rejet is made, will make this issue worse.
This is why I always tell people to get a base line before making mods so they can feel how they mod changed the bike.

 

[cxman]

jack up the pods and install these

http://i1197.photobucket.com/albums/aa422/murrayfeldman/CB750DOHC/IMAG0071.jpg

http://s1197.photobucket.com/user/murrayfeldman/media/CB750DOHC/IMAG0077.jpg.html?sort=3&o=3

problem solved

 

[surffly]

4 carbs sent so hard it can never be learned.

Also not sure how someone's copy of a copy of a "back in the day" part will help at all.
Just change the unknowns yet again.
Get a bike running 100% stock, then mod it.
Also mikuni carbs, or knock offs of mikunis, are not gods gift to old bikes.

 

[cxman]

you know surffly i dont copy anyones designs i develop my own

i supply carb kits all over the world and thru well respected vendors

all my carb kits are jetted and test run and balanced before shipping per customers needs lol

as for being the answer for some old bikes a lot of people feel they are

new can be just the simple reliable answer a lot of us need sometimes cv s dont cut it

look thru this it is one type of kit i make

http://cx500forum.com/index.php?/topic/18043-first-impression-of-murrays-carbs/

 

[Steve F]

My CX runs a set of Murray's carbs with his custom inlets and throttle cable etc. I ride a very popular bike road here at least a couple of times a week as its pretty much at my front door so its a good test of modifications. The thing I notice most after the Carb swap is how much more torque my cx has and how I can just roll the throttle on and stay in a taller gear out of the uphill corners. I can't give any definitive figures but compared to the stock honda carbs, which were jetted etc, these things are a huge improvement

As an aside my bike is pretty heavily modified and will hold its own against much newer machinery in the tight stuff.

Cheers
Steve

Sent from my MZ604 using Tapatalk HD

 

[surffly]

you know surffly i dont copy anyones designs i develop my own

i supply carb kits all over the world and thru well respected vendors

all my carb kits are jetted and test run and balanced before shipping per customers needs lol

as for being the answer for some old bikes a lot of people feel they are

new can be just the simple reliable answer a lot of us need sometimes cv s dont cut it

look thru this it is one type of kit i make

http://cx500forum.com/index.php?/topic/18043-first-impression-of-murrays-carbs/

Easy killer.
It's not a new idea.
Posa did it in the 70s and then cycle X copied it a few years ago, and now a few people are copying it again. At least for the sohc cb750. That bike also never had CV carbs.

Anything advertised as pre jetting makes me laugh inside.
Can someone get something close for a persons needs? Sure. But there are way to many variables to account for.

 

[Kamn]

I dont think cxman was saying its a new idea, I think he was saying that if you dont feel like fuking around with your old carbs and want something new that will work out of the box......here you go

Since I do have a carb set from him, I can tell you that there is communication before shipping to you with respect to what you have done to the bike or plan on doing. The mans got 40 plus years in the field and spends crap loads of $$$ in R&D + he stands behind all his work.

 

[mydlyfkryzis]

The reason 4 carbs with pods is so difficult to tune, is that the outer carbs get different temperature and pressure air then the center carbs. How to fix this?

Stock Airbox rectifies this.

CXmans solution works too. With the cylinders siamesed, both pairs of cylinders are equal, and since the location of the pods is similar, bot receive similar air temperature and pressure wise.

CXmans solution also has a longer intake runner, which is usually a plus for performance too.

 

[cxman]

the big thing the air box provides is a stable air cushion for the sensing port in the cv carbs

remember cv stands for constant velocity so that is the air boxes job and why they are such a pain to tune

without it almost impossible across the entire powerband

there is no issue with the mikunis the have mechanical slides and fuel flow is regulated by the air velocity passing by the main

jet once the slides are open and the main needle raised

 

[surffly]

The OP has a sohc cb750.
That bike doesn't have CV carbs

 

[mydlyfkryzis]

Even with non cv carbs, the plenum effect is advantageous. If you look at any FI car engine, they add a large chamber before the intake runners.

Even the old, large round air filter on the old cars creates a plenum. Still air before the intake rather then turbulent air increases air flow and provides better effects in the carb.

Can you work without it? Sure, but it is not optimal.


Sent from planet Earth using mysterious electronic devices and Tapatalk

 

[cxman]

one of the simple features of the mikuni smooth bore is the built in velocity stack to smooth air flow

it makes a huge difference

 

[hmarston]

I second those who give Murrays Carbs a thumbs up. I didn't do enough research before pulling out my airbox and throwing on a 4-into-1 exhaust. I had headaches over my carbs' inconsistencies for a year and some before hearing about Murray. His carb set up has worked wonders for me and added considerable torque and throttle response! My cb750 wants to jump wheelies on takeoff now!

Hunter
1979 CB750LE