[old boy]

Hi mikuni cv carbs on suzuki gs850 . been working on my trike for some time, now its out on the road it hangs back after third gear pops back from carbs just wont run nice starts on the button. Ive done whole carb clean brand new inlet boots floats spot on ive noticed it has over sized mains 130 instead of 115 so in theory should run rich, but dont . i think the pods are cheap and nasty ive put masking tape round all pods leaving about half inch at the narrow end and now trike runs almost perfect just a bit of deceleration backfire plugs are all a good colour .could this bad running problem be just useless pods or have i missed something, ive got 142 new mains ordered to try giving it more fuel to air. Oh forgot the carbs are properly balanced and float levels are spot on. Ive tried to cure the problem by adjusting mixture screws the tape blocking some of the air has the best results ..... engine is good with almost new engine compression. If it may just be the pods letting in to much air any recommendations for better pods would be appreciated

many thanks in advance

 

[SemiFast]

Hi mikuni cv carbs on suzuki gs850 . been working on my trike for some time, now its out on the road it hangs back after third gear pops back from carbs just wont run nice starts on the button. Ive done whole carb clean brand new inlet boots floats spot on ive noticed it has over sized mains 130 instead of 115 so in theory should run rich, but dont . i think the pods are cheap and nasty ive put masking tape round all pods leaving about half inch at the narrow end and now trike runs almost perfect just a bit of deceleration backfire plugs are all a good colour .could this bad running problem be just useless pods or have i missed something, ive got 142 new mains ordered to try giving it more fuel to air. Oh forgot the carbs are properly balanced and float levels are spot on. Ive tried to cure the problem by adjusting mixture screws the tape blocking some of the air has the best results ..... engine is good with almost new engine compression. If it may just be the pods letting in to much air any recommendations for better pods would be appreciated

many thanks in advance

Not exactly too much air just too much for the amount of fuel.
When going to a free flowing air inlet system (pods) you'll need to make substantial changes in carb tuning.
You might need to go as much as 5~6 steps larger than stock (maybe more) on the main jet.

 

[old boy]

pods

Not exactly too much air just too much for the amount of fuel.
When going to a free flowing air inlet system (pods) you'll need to make substantial changes in carb tuning.
You might need to go as much as 5~6 steps larger than stock (maybe more) on the main jet.

Hi larger main jets were already in the carbs the standard are 115 it had 130 and now ive fitted new 142 mains and still need tape covering the pods in fact i test drove it without any pods just bare carbs and there wasn't really much difference between that and with pods on (without tape ) . from 115 to 142 mains is quite a jump thats why im thinking **** pods and if there are pods with some sort of insert filter ???

 

[SemiFast]

Wow, That's about 11 steps if my count is right. ? !
I'm thinking pod air filters are all about the same, just air filters.

 

[old boy]

these filters have nothing inside them no filter of baffle of any kind , held up to the light you can see through the metal gauze they make almost no difference as to running with no air filters on at all .I cant believe I still need bigger main jets , then how big this is becoming a right pain t, think ill just leave the tape on unless i can find some new filters that will work

 

[jcrubin]

Hi larger main jets were already in the carbs the standard are 115 it had 130 and now ive fitted new 142 mains and still need tape covering the pods in fact i test drove it without any pods just bare carbs and there wasn't really much difference between that and with pods on (without tape ) . from 115 to 142 mains is quite a jump thats why im thinking **** pods and if there are pods with some sort of insert filter ???

Substantial is true!! But its also Main jet needle angle, notch, pms setting pilot jet and float level. I figured all of this out by using a computer. I have found after years of being told that some folks can tune a carb by feel or licking the tail pipe or whatever, that an O2 sensor is king. So I welded a bung into my pipes and slapped on a tuning computer when I need it. I find it better than shooting in the dark

My $.02

 

[old boy]

Hi the only thing ive not looked at is the needle and what notch their in , ill have to do that i know , but as you say maybe if i can find a bike shop equipped with the right gear to sort out the exhaust may give me a better idea carbs have new mains and pilots , also new needle valves and filters ive set the float levels with vernier calipers carbs properly cleaned , diaphragms all good getting a bit peeved on keep taking carbs off instead of riding out in this glorious weather we are having in the uk at this time

 

[SemiFast]

these filters have nothing inside them no filter of baffle of any kind , held up to the light you can see through the metal gauze they make almost no difference as to running with no air filters on at all .I cant believe I still need bigger main jets , then how big this is becoming a right pain t, think ill just leave the tape on unless i can find some new filters that will work

That's normal because running pod filters is almost like running it with no filters at all.
The stock air box probably restricted the air flow quite a bit. Pod filters, very little restriction.

 

[SemiFast]

Just a thought.
When the pod air filters are installed, they don't block any of the air jets at the back of the carburetors do they?

 

[jcrubin]

That's normal because running pod filters is almost like running it with no filters at all.
The stock air box probably restricted the air flow quite a bit. Pod filters, very little restriction.

They had to do that to meet loudness laws, which I find funny, having never really considered my intake to be that loud. Granted, I can hear it with the pod kit so theres that. The 87-93 mustangs were notoriously asthmatic for the same reason. This was the first upgrade done. But they had EFI, so it wasn't an issue. If you put a pod kit, or even worse, just pods, and an after market exhaust on a carbureted bike, there is no way you can expect this to work. Furthermore, Because, Jets and needles have an overlay of activity, each one reacts with the other. There is no one jet upgrade or one needle upgrade or one turn of a screw, this is not a thing.

 

[SemiFast]

If you put a pod kit, or even worse, just pods, and an after market exhaust on a carbureted bike, there is no way you can expect this to work.

Yeah, it's a whole new ball game when pod filters are installed. Major carb re-tuning will be required.

 

[old boy]

no they dont block anything they slide over the carb and held wit jubilee clips , now you have me thinking ill take one off and look where it fits on inside of pod , if it has a stop ledge inside that could maybe block the hole that leads to the mixture screw i believe, but thinking on ive tried without the pods so i doubt thats coursing the trouble im sure ill sort it sooner or later thanks everyone for your help

 

[old boy]

Hi im back talking about my pods again, just last wk i googled where to buy new pods, plenty came up, but so did a few very interesting vids and explanations as to why ive had to put tape round the outside of my old pods to get engine to run anywhere near good. Apparently you cant run pods on cv carbs, that is cv carbs need vacuum to raise the side and needle( not had a bike since my teens now nearly 70 I didnt know this) So by putting tape round the pods I actually without knowing was doing the right thing, although unsightly. Other people on these vids did their own similar quick fixes. my fix is with the new pods ive cut some of the rubber ledge away that was covering the kidney shaped hole at top of carb mouth, then measured the inside of pod from top to bottom, cut and shaped some canvas type fabric (fire proof) leaving a 1\4 inch gap at bottom for air intake super glued it inside the pods, then just in case it should come unglued cut some 1\4 inch square holed wire mesh fitted in the rubber mounting so as to stop any unglued canvas from entering the engine. Job done works a treat. There are know doubt better ideas and fixes than mine, but im happy right now engine runs fine now where over the last year ive been wondering why the hell i was having so much grief and didnt know why. So anyone trying to run pods on cv carbs and having problems, all you need to do is work out how much air you need to restrict and how you want to restrict it safely for best performance. hope this throws some light onto the pod\ cv problem.