Trouble running pipes and open air filters on a GT380?

[hahahaurugly]

Getting a GT380 cafe project going and have some questions about how the bike will run with individual filters and pipes? I have a beat stock air cleaner and stock pipes minus baffles right now and it's running but not super well. I would like to move to individual velocity stacks with screens and outerware prefilters or K&N pods along with a 3-3 set of pipes. Does anyone have base line data for jetting with intake mods, pipes or both???

[Vintageman]

I would get it running well stock first. Then you have a reference point.

For me 3-3 into pipes (jemcos) did not affect my jetting over stock exhaust. If you plan to run it WOT I suppose you my up the main jet a size won't hurt. But I ran stock jetting for for many miles. As you hear anyone say CHECK YOUR JETTING CAREFULLY if you change anything. I now run GT550 carbs on my GT380

Pods ( Vomit). If you must not use the wonderful stock air box with a oily fresh OEM filter and run pods instead you will most likely need to change jetting for that reason. I have no answer for you (research RD350/400 stock air box versus non stock. It’s crazy how much they change it). I don't think the GT380 will requires as much change (d, but who knows. If me run stock air box (get one of ebay and new air filter probably same as good set of pods). If you like induction noise remove rubber snorkel off back side of stock box and maybe up main jet one step I did this and stayed stock jetting , but not for too long for induction noise with helmet on hurt my ears. Maybe you are trying for a cafe look. Maybe use OEM 1 to 3 boot and use a can single filter (like many RD boys run)

Your bike -jetting is not easy and takes time. If you up size main jet a lot, think about riching needle jet (change clip pos)

[hahahaurugly]

Thanks for the input, the air filter rotted away in the last 20 years. It turned to oily dust when I touched it and as far as I can tell it's not avalible anymore. The snorkel is gone as are the baffles, I have a single layer of corse foam zip tied to the filter cage and I replaced all jets with stock.

[Craig380]

Stock airfilter foam does still come up on eBay from time to time. As Vintageman says, it's a lot easier to dial in the carbs when you're using the stock airbox and filter.

If you do fit chambers with the stock airbox & filter, you'll probably find the carb settings are pretty close to stock, maybe just needing a small tweak. With pod filters, it's pretty much starting from scratch.

[Coyote]

Pods (El Cheapo brand) require upping the pilot jet by at least one size to compensate for the increased air flow. Would you believe 3?. That's what it took on my 550 with pods and chambers. Never again. Give me stock any day. It takes a long time (waiting) and extra $$ to ever get it tuned near right. Every engine requires something different in attempts to tune. For that reason, there are no rules of thumb.

[tz375]

As the guys have already mentioned, every bike is a little different.

Cheap pods restrict airflow and lose power, so avoid them like the plague. They also do not filter well.

I run UNI filters or open stacks on my GT750 with chambers and CV carbs.People say that it cannot work but I manage to do 13.1 second 1/4 mile times @107pmh, and it rides like like a slightly perky street bike.

Some chambers require significant changes to main jets, pilot jets and needle jets and others not so much. RD's go up huge numbers of main jets with chambers and pods, but GTs - typically not so much.

As Coyote mentioned, start with one size up on pilot jets and 2 up on mains and get it on a dyno with gas analysis to see what it is doing.

[Coyote]

Unless something has changed, RedZone ran quite well with cheap pods (oiled). jabcb would have to verify. I don't think he has changed a thing except the old lead acid battery petered out. I did try those huge sponge UNI's and nothing at all. The motor acted like it didn't care what was there so I put the pods back on for aesthetic purpose and didn't look back.

[hahahaurugly]

I know I will have to play with jetting. I was more looking for input or warnings if the bike just doesn't run well with both done.

[jabcb]

RedZone runs fine. Max ride so far was an 80 mile ride on the hilly Pennsylvania backroads.

Entered RedZone in the Cafe Racer Magazine Readers Ride-In Bike Show.
Lots of tough competition.
If you look closely in the October/November issue, page 34, upper left pic, you can see just enough of RedZone to recognize it.

Did suffer the worst problem so far when I rode it to the bike show — the right front turn signal bulb burned out.
Coyote definitely did a good job sorting the bike out.