Is the power in the pods or 4 into 1?

[glib]

1983 GS1100E. My first time riding one with pods and a 4 into 1 exhaust (older V&H with the can-looking muffler). I had to get the jet kit because it bogged badly without it but I am really surprised at the throttle response compared to my ES. I haven't been out of town yet so I don't know all that it can do but the low end torque is very obviously improved and mid-range as well.

My question for those of you with experience with these modifications: Is the added performance coming from the pods or the exhaust and although it is probably both, which is the more significant mod? I want to keep my ES stock but at the least I am going to get a jet kit (3133 stage one) suitable for improving the fueling of the stock setup. A K&N filter in the airbox should make a difference as well, correct? How restrictive is the stock exhaust?

 

[Guest]

The stock exhaust is really quite good, not very restrictive at all, for a stock, quiet system. Test after test has proved that even the best 4-into-1 pipe only makes power worth mentioning in the upper RPM range, and usually at the expense of mid-range power. Most of the power charts show a slight dip at about half the speed where it makes maximum power. On the other side of the engine is a different story. The stock airbox is a bit restrictive, so removing it and putting on pods REALLY allows more air to flow. More air = more power (as long as you add the right amount of extra fuel, too). I am not sure just how much power is added, but more noise must certainly​ be more power, right? :-k :-\\\

 

[posplayr]

A lot of people get rid of the stock pipes due to the extra weight, and then the pods and jetting just follow.

On the other hand if your want to look stock , keep the pipes and put in the K&N airbox filter and up your main jet a couple of steps. It runs lean and the less restrictive filter well need even more fuel.

If you keep teh stock pipe you probably do not need the jet kit which has the properly tapered needle for the 4:1 power dip.

 

[Rob S.]

...On the other side of the engine is a different story. The stock airbox is a bit restrictive, so removing it and putting on pods REALLY allows more air to flow.

As an example, before I got re-jetted, I had to cover about 90% of the pods to get it to run well. 75% covered and it was still bogging badly!

 

[tkent02]

Find a Tri-Y header and keep all of that midrange and get a bunch more up top too. Pipe makers sell 4-1 pipes to riders influenced my motorcycle magazines, top end power is all they ever write about. 4-1 is the type they mostly make. It's very hard to find a decent Tri-Y, but there are a few.

Pods can make more power, but only if the carburetion is tuned correctly. They same to change carburetion requirements more than pipes do. Takes a lot of time and effort to get it perfect, especially if you need it to run well at a variety of elevations. That's why the air boxes were made restrictive in the first place, to help economy, emissions and rideability at different elevations. I have ridden a lot of bikes with pods and pipes, few are tuned well at all, only ridden a couple that I would consider perfect. One of the perfect ones was an 1100E engine like yours in a 750, owned by a motorcycle mechanic who had access to fancy tuning equipment. That bike screamed anywhere from 5,000' where we live, up to 10,000', had great throttle response, with excellent fuel economy, like 55mpg. Most riders are content if it has decent throttle response and winds out to the red line without missing and popping too bad. Perfection isn't going to happen.

 

[glib]

K&N airbox filter and re-jetting sounds like the route for me! Cheap too...

 

[tkent02]

That's what I would probably do.

 

[Rob S.]

...Pods can make more power, but only if the carburetion is tuned correctly.Takes a lot of time and effort to get it perfect...I have ridden a lot of bikes with pods and pipes...only ridden a couple that I would consider perfect. One of the perfect ones was an 1100E...

Sounds like mine. Every time my mechanic returns it to me, he says, "This bike runs really well," as if he's surprised. I always say, "You tuned it."

But I live at sea level and have never been higher than 1500 feet. Too little to make a difference, I think.

 

[Dave8338]

That's what I would probably do.

Yeah... what do you know! Won't even ride an 'L'. ��

Too much flow with a 4-1 at anything under 7500...

 

[tkent02]

Oh, it's an L?? In that case part it out.

 

[Dave8338]

Oh, it's an L?? In that case part it out.

LOL... It appears that the carb and exhaust fourm is alive and well !

 

[Nessism]

K&N's flow lots of air because they don't filter very well.

 

[glib]

Anyone know what jet to use with the K&N and stock exhaust? I was thinking 120 or 122.5. More? The DynoJet jet for pods is huge compared to the stock 112.5.

 

[Guest]

Anyone know what jet to use with the K&N and stock exhaust? I was thinking 120 or 122.5. More? The DynoJet jet for pods is huge compared to the stock 112.5.

On my 80 GS750E, I run the K&N stock replacement filter and a RC 4-1 pipe. All I did was step up the mains from 112.5 to 115.5. No flat or fat spots, just a good running engine through out the RPM range. Though remember I'm at 4,000 ft and do a lot of riding there to 9,000+ft. Surely your 1100ES had bigger main jets then 112.5 because those are the stock size in my 750.

 

[posplayr]

Anyone know what jet to use with the K&N and stock exhaust? I was thinking 120 or 122.5. More? The DynoJet jet for pods is huge compared to the stock 112.5.

The DJ and Mikuni jets use a different number system(one being size and the other flow rate but cant remember which is which). There are conversion charts available on line (there are also approximate scale factor ratios) or you (what I do) can just remember to subtract 10 from the DJ to get the approximate Mikuni jet number. So the 112.5 Mikuni is like a 122.5 DJ or the closest you can get.

If everything is bone stock and you have a California bike you can figure to have to increase the jet two steps (I think I mentioned this before).

Don't even mess with the DJ kits. Just order a set of Mikuni's that are 117.5.

This would be like a 128 DJ .


If you want to get involved also get a set of 120 Mikunis and see if that is too rich for the bike. You are kind of splitting hairs now and without an O2 sensor it is going to be hard to tell.

If it doesn't pop on decel and does not hunt on part throttle then you are good.

As an example with an 1981 GS750 bone stock but a paper filter CA bike, it ran very well although a little lean on stock jets. I put in 1100 intake cam and it then hunted at part throttle. I went up two steps and it was perfect.

As I mentioned before you only need the DJ kit if you go 4:1 because the scavenging effect of teh 4:1 needs to lean out the mixture at the mid RPM where the system is in reverse flow(I forget the correct term).

 

[glib]

On my 80 GS750E, I run the K&N stock replacement filter and a RC 4-1 pipe. All I did was step up the mains from 112.5 to 115.5. No flat or fat spots, just a good running engine through out the RPM range. Though remember I'm at 4,000 ft and do a lot of riding there to 9,000+ft. Surely your 1100ES had bigger main jets then 112.5 because those are the stock size in my 750.

I have no idea why the ES comes with 112.5 stock jet but it's true. Mine had 115s and I still think it was lean--pinging from a stop when it gets warm (normal temp range).

The DJ and Mikuni jets use a different number system(one being size and the other flow rate but cant remember which is which). There are conversion charts available on line (there are also approximate scale factor ratios) or you (what I do) can just remember to subtract 10 from the DJ to get the approximate Mikuni jet number. So the 112.5 Mikuni is like a 122.5 DJ or the closest you can get.

If everything is bone stock and you have a California bike you can figure to have to increase the jet two steps (I think I mentioned this before).

Don't even mess with the DJ kits. Just order a set of Mikuni's that are 117.5.

This would be like a 128 DJ .


If you want to get involved also get a set of 120 Mikunis and see if that is too rich for the bike. You are kind of splitting hairs now and without an O2 sensor it is going to be hard to tell.

If it doesn't pop on decel and does not hunt on part throttle then you are good.

As an example with an 1981 GS750 bone stock but a paper filter CA bike, it ran very well although a little lean on stock jets. I put in 1100 intake cam and it then hunted at part throttle. I went up two steps and it was perfect.

As I mentioned before you only need the DJ kit if you go 4:1 because the scavenging effect of teh 4:1 needs to lean out the mixture at the mid RPM where the system is in reverse flow(I forget the correct term).

I was glad when you said previously that I would not need the DJ kit. I didn't want to spent he money on it anyway. Turns out I had 122.5s in another bike. The PO had tried to make them work with pods and it just wasn't working. I put the jet kit in that bike (which now I found needs a head gasket) so this morning I put the 122.5s in my ES with a K&N filter I had. I could see that they were slightly bigger than the 115s that had been in there. Definitely not hogged out like the DJ 138s in the stage three kit. They were also marked the same way as the Suzuki jets for what it's worth. I just took it for a quick ride and I could not detect a flaw in it now. Really sweet. You may be right that 122.5 is bigger than necessary. Is there any potential damage to being up a step more than necessary?

 

[posplayr]

being a little rich only eats up more gas and adds a little more power. It is better to prevent predetonation and will make the pipe a little sooty. generally when jetting you go fat (rich) and back it off from there.

I would guess since it runs fine at 122.5 that you might get some mid range bobble with the 120's which you would have to hassle to find out.