Topic: 75 cb750 running issues

[jamesb]

first off the bike is a 1975 cb750 with 836 kit in it that's all i know about that part do not know what was done.the original carbs where nasty took them off put some other carbs on it. it ran okay but had some idle problems after it was warmed up or hot lets just say about 5 miles of running time. so tonight i took the original carbs apart and cleaned them soaked them for awhile took all the parts out and cleaned them put it back together ran good better than the others then in about 5 minutes of run time went to take it down the street. and it started to back fire through the carbs and pipes it was literally flames coming out of the pipes and carbs but only on the left side it seemed like. i took out the idle screws could this be where my problem is for starters the bike has pods and drag pipes on it the guy i bought it from said it ran good he parked it because he got a new bike.how do you adjust the idle screws thanks for any info i google searched and couldn't find anything about it. i can't use the other carbs they are going back on my other 75 cb750 so i can sell it.thanks again 

[bollingball]

I was going to say download the manual and read it
But in this case the book  does not cover PODS.
There are people on this site that use them. I don't have the answer. But try this. Go to the  goggle costom search tab and type 75 750 to 836  pod setup. Some of the pod people will chime in.
I think you will get more and better results like that.
One more thing get ready for some heat. lots of people do not like them

Ken

[ekpent]

Since it is backfiring etc are you certain that the timing is spot on and the points etc are good. A lean condition with the carb settings would also start to be apparent after 5 minutes,could make the bike run too hot.

[jamesb]

i don't think timing is a problem it ran decent with the other carbs on it. the only problem was when it ran for awhile and when you came to a stop it would high idle on it's own then then would go down to a slow idle and die. i have a pamco ignition i'm going to install today. i have read that also 125 jets help with running pods and drag pipes i just need to learn how to install them. i'm not use to going in this deep wih carbs.i know the major problem is pods but beings it's a chopper and putting a stock airbox on it wont work it's a amen savior frame no room.

[Xnavylfr]

Pods are a real Biotch to get set up right. The high idle then settles down, sounds like you have a air  leak problem around the boots.
You are welcome to join also on   http://hondachopper.com/   they have a real good garage section for you to use to TS your bike, and trust me someone has already gone through this on their chopper and has an answer for you.

We are kinda partial to SOHC Honda Choppers .

Xnavylfr(CHUCK)

[jamesb]

is there a thread on replacing jets i can't find one a breakdown something this thing is getting ready to go to f@#king junk pile

[lucky]

is there a thread on replacing jets i can't find one a breakdown something this thing is getting ready to go to f@#king junk pile

So if you cannot fix it ,no one gets to have it?

With pods you will need to increase the size of the idle jets.
Try #42's.  Main jets #120's

You did not tell us the slide needle clip position (from the top).

You said "I took out the idle screws" It only has ONE idle screw, so that means you took out the mixture screws. No wonder it is all messed up.

[jamesb]

that's what i was trying to get at in a earlier post i do not know what the f@%k I'm doing i can not afford to have them done.I'm going to put the others back on and deal with the high and low idle. i have all the jets i can not find nothing on how to remove and replace them  and I'm sorry about the idle screw i meant the mixture screws.I'm definitely the wrong guy to mess with carbs.all i need is a breakdown of the carbs and i'll start all over. my 550 i mhave pods on it my 350f pods and never had a damn problem with them but this piece of sh!t cb750 chopper is getting ready to be crushed.i think it's really the 108 degree days we have been having my nerves have been shot. so how dom you set the mixture screws and replace jets all i need is a link to a web page

[seanbarney41]

Hey James. calm down...I get like that when it's really hot too.  Put your mixture screws in.  Turn them all the way in 'til they gently seat....then, back them out 1 full rotation.  This will be a starting point.  Once you get these screws set, ride it around and see if it runs any better.  Do you have any sort of manual?  That will at least show you the proper assembly and baseline settings.  The factory manual is available for down load on this site.

[lucky]

I grew up in the desert. It was 114º many times. You can do some silly things and even die if you get to out of control.

Let me tell you some basic things that can help you.

A carb is sort of like a toilet . Not kidding.
It has a float to let in gas and then maintains the level of that gas in a bowl just like your toilet in your bath room.

That valve is the float valve. It is 90% of the operation of the carb.
There are two kinds of float valves. valves with rubber tip needles and valves with all metal needles.
You cannot get those mixed up.
If they are old they are not to be trusted. Just replace them.
The float has to adjusted properly to make the gas level higher enough or low enough. Critical.

There is a main jet LARGE.
 and a Idle jet VERY SMALL hole.

There is a slide that goes up and down that regulates the air coming in the engine.
There is a needle on the bottom of the slide that regulates the amount of gas coming into the engine.

Thats it basically.

That float I was talking about is a small delicate part.

More later.

Go online and look up a few MOTORCYCLE carb rebuilding videos.
NOT just ONE but several.  Watch those and you will start to understand.
Some are better than others.

IF the person making the video does not know the names of the parts, or says "I think"
then go to another video.

[jamesb]

i put the other carbs on with a breadbox breather the breather has no filter in it but it runs a lot better.

[lucky]

i put the other carbs on with a breadbox breather the breather has no filter in it but it runs a lot better.

Well you have just learned something by experience. No better teacher.