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Discussion Starter #1
I posted on here a week ago about carb settings, came a long way since then haha, but now I'm stuck again. SO, long story short, I have a 1979 CB650 with Pod air filters on, and i think I may have carb related issues still. Its gone from not running, to now running pretty damn clean, with good throttle response, BUT the idle RPM is super high. Heres what I've done so far up until now. Ive cleaned the shit outta the carbs multiple times, got all the same size main jets, since before there were different sizes on, i got 120's for them since i saw someone else post thats what he has on the same bike. I've pulled the press in jets out and cleared them all out and made sure there was no build up in there and put them back in properly. Also I've tried to set the idle mixture screws to different positions to see what changes I've gotten from that, but nothing major as of yet. So I'm kind of stumped now on why my idle is pretty damn high, and the idle screw is also backed all the way out. Also this is all with choke down, if the choke is pulled all the way up it sounds like the bike will explode from the RPMS.. Im able to take it out on the road and when its in gear it wants to take off because its idling so high. I noticed today that the #2 & #3 pipes are way hotter than the #1 & #4 pipes so I'm sure thats not right at all, all my spark plugs are clean and look brand new.......Anything of help would be greatly appreciated. thanks
 

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Cleaning the carbs should only need doing once if it's done properly (unless you are putting shit back in them of course). I'd maybe leave off riding it a bit though eh??.

Which end of the spark plugs look new and clean? the business end or the bit that pokes out of the engine with the wire on?

You may well have an airleak on the inlet side of the carbs/mounts and the choke circuit is feeding it the extra fuel to rev it's tits off when you use it.
 

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Are your carbs actually sat closed at idle, I meaning sat fully closed away from the screw as it sounds like its adjusted all the way out. I'd check this first to be 100% sure.

Next I'd check the airleaks.. do you have block off pipes, mine was running a bit ropey at the weekend and noticed one of the blanking pipes and come off.. the next thing is could the ignition be too far advanced??

Ive ridden a bike with high idle, not fun and as pwalo suggests I'd keep off it.
 

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I've not had a lot to do with those funny bellcrank affairs but from what I gather they require a good bit of patience and careful, meticulous work to get the best out of them.
 

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It sounds like you have an air leak. Next step is to find out where. Get a can of starting fluid and start spraying carb junctions until the idle jumps.

Also what's the rpm you are saying its idling at? These bikes idle at like 1100-1200 not the 700-800 a car idles at.

When you say idle screw, do you mean the air bleed screw or the throttle stop. If it is the air bleed screw then screw them in to bottom them and then take them 1 and 1/8 turns out. If it's the throttle stop screw that's actually your idle adjust and if it's backed all the way out, well I don't know what to tell you but check for air leaks first and slide height second.

Also, throw those pods away and put the stock airbox back on.
 

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;) so it doesn't count if you are doing it out in the woods using a Swiss army knife and a thorn from a nearby bush?
That's when it has to count as it's a long push back to Eden honey...... I learned a lot of my craft in muddy fields; now I bathe in the glory of owning an ultrasonic cleaner in my semi-carpeted workshop.

For the OP: Do as Geeto suggests with air testing the pods. Standard airbox and carb settings will make your life a hell of a lot easier.
 

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Discussion Starter #8
Thanks for all the input guys, I had to do multiple cleanings because i had crap in my gas tank that kept clogging my jets up, so i took care off that and then put a fuel filter on since there wasn't one on when i got the bike. So today ill go get a socket to remove the inner two spark plugs, check the entire plug, and check for air leaks. What is the best way to check for air leaks? sorry I'm a newb at this and learning everything as i go, which I'm actually enjoying even though its a pain haha.
 

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Discussion Starter #9
Cleaning the carbs should only need doing once if it's done properly (unless you are putting shit back in them of course). I'd maybe leave off riding it a bit though eh??.

Which end of the spark plugs look new and clean? the business end or the bit that pokes out of the engine with the wire on?

You may well have an airleak on the inlet side of the carbs/mounts and the choke circuit is feeding it the extra fuel to rev it's tits off when you use it.
The side of the spark plugs that stick out look brand new, I'm going to remove the entire spark plug and then ill get back to on how they look. ill also check for those leaks, thank you..
 

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What is the best way to check for air leaks?
Either spray it with a mist of light oil around the inlet stubs while running and the revs will drop due to the oil sealing the leak, or mist a fast flash volatile solvent in the same area which will cause a slight initial dip in revs and then it'll race it's tits off when it pulls in the extra combustibles.
 

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Discussion Starter #12
take a picture of your carbs on the bike, sometimes people don't push the carbs all the way in to the intakes when they are re-installing.

For when you pull the plugs:

View attachment 31010
sweet, thank you. Yeah i make sure to put them all the way back on when i take them off.. I wonder if i can post a video on here from my phone, I'm going to try that here in a minute..
 

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Discussion Starter #13
I just posted the video on YouTube so you guys could check it out. This is actually before I found out that the spark plug in #1 was just sitting in there, don't think it was actually even sparking, once I tightened it up, the idle got even higher.

https://youtu.be/d2RyESDsPE8
 

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Discussion Starter #15
I did re use them, they're in decent shape. I actually planned on getting new ones once I figured this all out..
 

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exhaust air leaks don't make a difference on idle quality. They have their own problems like the potential to crack a valve and making an awful racket but as to the idle it shouldn't affect it. You want to look for air leaks around the intake rubbers.

But yeah you should fix that.
 

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It's a stud. Get two nuts that fit the thread, thread one down as far as you can go while maintaining contact with the threads, then take the other nut and back it up against the first one till they are putting pressure on each other (pal nutting). then put a wrench on the nut closest to the block and use it to take the stud out. It will have corrosion and thread locker in there.

like this (ignore the arrows)
twonuts.jpg

If you don't have enough threads to get two nuts on there then go buy a tap and die set and use the die to put more threads on the stud.
 

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Any luck? I've used starter fluid before. A quick burst through the straw should keep the fumes from entering the carb filter as long as you keep it close to the part you are checking.
 
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