M
MisterCinders
Guest
Since a PPP post (pods, pipes, panic!) comes up almost daily, let's get some basics down about pod filters and exhaust mods.
What's Wrong With You?!?
First, changing your bike from stock makes you a terrible person and is a direct cause of erectile dysfunction, famine in the 3rd world, and all other human suffering. You are literally a monster.
With that out of the way, here are some things to know about your new role in this world as a villain.
Do I Really Need to Rejet?
Yes.
Suzuki set the jetting for these bikes based on the stock airbox and stock pipes, generally a 4-2 setup. Changing the parts at either end of the system affects your carbs. Open pipes or a 4-1 allows more airflow out of the engine, reducing back-pressure. Pod filters permit air to enter the carbs faster than the more restrictive stock airbox. The amount of the increase depends on the mods. Generally, changes to the pipe add less air than changes to the filter. These changes accumulate, so adding a pipe may require only a little adjustment to you existing jets, adding pods definitely will require jetting changes, and going with pods and a pipe absolutely requires substantial adjustments.
Say a Proper Good-Bye to Stock Jetting.
Before you change your setup, get the bike running with the stock parts if at all possible. It is much easier to adjust jetting from a working baseline. If your carbs are dirty and clogged or your valves are out of whack, you will lose your mind chasing those problems down while simultaneously figuring out new jetting.
Even if your bike runs well, you need to clean those carbs and make sure your valves are right. There is no escaping this. While you're in the carbs, take stock of your current jetting. No one here can tell you what jets you need unless you tell us what is in there now. If you have a stock setup, you probably have standard jetting, but who knows what's happened in there over decades of PO abuse. Compare your jets to the stock specs here.
If you can't reset the bike to stock (my bike came with a 4-1, for instance), you need to cuddle up with these specs and your current jetting for reference points.
OK ? I am Ready for Mayhem. Give Me Jets!
Slow down, killer. If it were that easy, we would not have PPP threads every day.
Remember, the changes you make to your bike dictate the changes you need for jetting. There is no simple rule for what jets and sizes to plug into your bike. This post has some pretty good info to find a starting point. You can also SEARCH THE FORUMS for threads on Pods. If reading that pile of nightmares doesn't drive you into alcoholic despair, you might find some jetting help there.
"Choose" Your Weapons
Your carbs present the first crossroads in your path to evil ? CV or VM?
CV ? Breakdancing in your Members Only Jacket
Bikes with the new-fangled CV carbs may get to (or have to) use the crutch of a DynoJet kit. The good news is that some smart dude put together jets and other bits for your bike. The bad news is that costs money AND you may have no other choices since the stock needles for those carbs often are not adjustable and/or have tapers that don't play well with all that breezy air. DynoJet has your starting point here.
Basically, if you go with pods or pods and pipe, grab that Stage 3 kit. It will get you very close, but plan to make further adjustments.
VM ? Disco Never Died
With hipster VM carbs, don?t be too smug. Sure we have more game with the ladies, but there's good news and bad news for us as well. Our needles usually (but not always) are adjustable, so we are not slaves to the DynoJet cult and can spend that money on bell-bottoms and lava lamps as God intended. OTOH, we get no short cuts or pre-packaged kits to launch our jetting adventure.
BTW ? if another person tells me to "just get a Stage 3 Kit" for my 1978 VM26s, I will not be responsible for the ensuing bloodbath.
So we have even more trial-and-error to work through. Based on your mods, figure out roughly how many sizes up you need that main jet to go. That linked guide suggests +6 sizes for pods and pipes. My GS750 stock mains were 100, and I am running 117.5 now, but stay tuned
for changes.
With a target size in mind, order main jets at -1/0/+1 of the target size ? so if you think my jetting might work for you (I wish it worked for me) ? order 115, 117.5 and 120 mains.
For pods and pipe, you need to raise the needle usually around 2 notches ? i.e., move the clip 2 slots down.
For the pilot, you might be OK with the stock size, with just some re-balancing of the pilot screws to shift towards more fuel. If not, you may have to increase the pilot size one step, or even two.
More to come.
What's Wrong With You?!?
First, changing your bike from stock makes you a terrible person and is a direct cause of erectile dysfunction, famine in the 3rd world, and all other human suffering. You are literally a monster.
With that out of the way, here are some things to know about your new role in this world as a villain.
Do I Really Need to Rejet?
Yes.
Suzuki set the jetting for these bikes based on the stock airbox and stock pipes, generally a 4-2 setup. Changing the parts at either end of the system affects your carbs. Open pipes or a 4-1 allows more airflow out of the engine, reducing back-pressure. Pod filters permit air to enter the carbs faster than the more restrictive stock airbox. The amount of the increase depends on the mods. Generally, changes to the pipe add less air than changes to the filter. These changes accumulate, so adding a pipe may require only a little adjustment to you existing jets, adding pods definitely will require jetting changes, and going with pods and a pipe absolutely requires substantial adjustments.
Say a Proper Good-Bye to Stock Jetting.
Before you change your setup, get the bike running with the stock parts if at all possible. It is much easier to adjust jetting from a working baseline. If your carbs are dirty and clogged or your valves are out of whack, you will lose your mind chasing those problems down while simultaneously figuring out new jetting.
Even if your bike runs well, you need to clean those carbs and make sure your valves are right. There is no escaping this. While you're in the carbs, take stock of your current jetting. No one here can tell you what jets you need unless you tell us what is in there now. If you have a stock setup, you probably have standard jetting, but who knows what's happened in there over decades of PO abuse. Compare your jets to the stock specs here.
If you can't reset the bike to stock (my bike came with a 4-1, for instance), you need to cuddle up with these specs and your current jetting for reference points.
OK ? I am Ready for Mayhem. Give Me Jets!
Slow down, killer. If it were that easy, we would not have PPP threads every day.
Remember, the changes you make to your bike dictate the changes you need for jetting. There is no simple rule for what jets and sizes to plug into your bike. This post has some pretty good info to find a starting point. You can also SEARCH THE FORUMS for threads on Pods. If reading that pile of nightmares doesn't drive you into alcoholic despair, you might find some jetting help there.
"Choose" Your Weapons
Your carbs present the first crossroads in your path to evil ? CV or VM?
CV ? Breakdancing in your Members Only Jacket
Bikes with the new-fangled CV carbs may get to (or have to) use the crutch of a DynoJet kit. The good news is that some smart dude put together jets and other bits for your bike. The bad news is that costs money AND you may have no other choices since the stock needles for those carbs often are not adjustable and/or have tapers that don't play well with all that breezy air. DynoJet has your starting point here.
Basically, if you go with pods or pods and pipe, grab that Stage 3 kit. It will get you very close, but plan to make further adjustments.
VM ? Disco Never Died
With hipster VM carbs, don?t be too smug. Sure we have more game with the ladies, but there's good news and bad news for us as well. Our needles usually (but not always) are adjustable, so we are not slaves to the DynoJet cult and can spend that money on bell-bottoms and lava lamps as God intended. OTOH, we get no short cuts or pre-packaged kits to launch our jetting adventure.
BTW ? if another person tells me to "just get a Stage 3 Kit" for my 1978 VM26s, I will not be responsible for the ensuing bloodbath.
So we have even more trial-and-error to work through. Based on your mods, figure out roughly how many sizes up you need that main jet to go. That linked guide suggests +6 sizes for pods and pipes. My GS750 stock mains were 100, and I am running 117.5 now, but stay tuned
for changes. With a target size in mind, order main jets at -1/0/+1 of the target size ? so if you think my jetting might work for you (I wish it worked for me) ? order 115, 117.5 and 120 mains.
For pods and pipe, you need to raise the needle usually around 2 notches ? i.e., move the clip 2 slots down.
For the pilot, you might be OK with the stock size, with just some re-balancing of the pilot screws to shift towards more fuel. If not, you may have to increase the pilot size one step, or even two.
More to come.
More recently, after changing the top end, I have the more typical lean issues, and have upped the pilot to 17.5. If you are putting fuel screws out to 2 turns (1.9), you might have better luck with a bigger pilot jet.
