Installed pod filters & open exhaust & now I get HORRIBLE mpg

I have a KZ650 & put in pod filters & 4 into 2 OPEN exhaust. Well my mechanic did. Now my gas mileage is horrible - about 20 mpg!! Is this normal when you don't use the stock filter & pipes? My mechanic said I need a new jet kit - stage 3.

If I install this will this make my gas mileage normal?

What should my average mpg be for this bike?

Or is there anything else I should do to get better mpg?

Thanks!

I get about 28.5 mpg on the KZ1000 with 3.5 gallon tank and same setup.

I know of someone with a Ducati Monster who upgraded his and put in a jet kit. It did increase his mileage.

Not too mention there is a strong gas odor coming from exhaust. It is wasting a lot of gas. And sometimes when my exhaust back fires, I get flames!! So anything else I can adjust for better gas mileage or do I need a stage 3 jet kit?

If its pouring in then you have a carb problem.

Float height set right?

I think stage I - stage II - stage III increase the amount of gas as you go up, with larger jets. You need to get it dialed in with exact jet sizes, not generic 'stage' market-speak. Without knowing what size jets you have now, its hard to tell you what to do.

Putting on the pod filters and opening the exhaust would flow more air and lean it out, we usually change to larger jets (your 'stage' kit) to richen the mixture back to an idea range. Did the mechanic do something else to richen the mixture?

try a differant mechinic!if hes got you running around with pods and open exhust and didnt touch the carbs it should be running really lean,get those carbs sorted out before you hole a couple pistons;)

PLUMMEN wrote:

try a differant mechinic!if hes got you running around with pods and open exhust and didnt touch the carbs it should be running really lean,get those carbs sorted out before you hole a couple pistons;)

True, but it sounds like the mechanic already rejetted too rich.

elcid, find out exactly what your mechanic did.

It would also help us to help you if we knew which carbs your bike has.

There were quite a few VM24 assemblies used on the KZ650 models as well as BS32 on the later models. Without knowing how the bike is jetted and what carburetors are being asked about, this question can't be answered in any precise way.

I am not sure what he did really. He just said that he could only adjust the jets so much & it will not run perfectly smooth until I get a jet kit. When I dropped off the bike it was in parts & not running. It has Mikuni carbs I believe. I got the pods & open exhaust because I assumed it would be something I wanted. The pods are easier to install & open exhaust sounds "cooler".

Is it possible that I don't need a jet kit at all & he just jetted poorly?

If I do need a jet kit, the which stage should I get??

Thanks guys!

Post edited by: elcid, at: 2008/03/01 13:57

elcid wrote:

I am not sure what he did really. He just said that he could only adjust the jets so much & it will not run perfectly smooth until I get a jet kit.

Jet's aren't "adjustable". When you rejet you remove your jets and replace them with jets of a different size (meaning the hole through which the gasoline flows is a different size).

Jets vary, but usually look something like this:

It has Mikuni carbs I believe.

Both the BS32 and VM26 carbs we're talking about are made by Mikuni.

If you have VM26 carbs, they should look something like this:



If you have BS32 carbs, they should look something like my BS34 carbs:

If I do need a jet kit, the which stage should I get??

There's a basic rule of thumb for determining what size jets to use and how to adjust the jet needles (if at all). You go up so much if you switch to an open exhaust, so much for pod filters. It's not a precise formula, just kind of a vague guideline to get you in the ball park. I'd recommend you do some searching through the forum to see what others have recommended. Wiredgeorge knows as much about this topic as anybody here...

Post edited by: guitargeek, at: 2008/03/01 16:13

Wow thanks for the detailed explanation. It is the first photo - VM26. That's what I have. He didn't do any "re-jetting" then. I guess he just adjusted or tuned them. Is there any way to adjust them with the pods & open exhaust so I get better gas mileage? Or will I have to get a new jet kit?

Post edited by: elcid, at: 2008/03/01 16:19

GG pretty much said it all. I don't think too many guys here run "jet" kits. The kit does not know what's been done to the bike. I think it would only put you in the ball park. I would pull the carbs and see what size jets, clip position, etc, your running now. The mech may have just slapped the carbs together and bolted them on on, you may need to clean and rebuild them. Floats could be way out of adjustment also. Ask the mech what he did to the carbs. There are too many variables here, let's start at square one and take it from there...