83GS550E Bigger Pilot Jets to cure no idle ?

[GQROD]

Hi all,

Rebuilt bsw30 twin carbs to stock factory specs. Pilot jets #35, Pilot air jet #145, mains #95 and #102.5, float hieght 20.5mm, valves adjusted to .13mm, new oem o-rings, boots pliable no cracks, good spark on all plugs.

Will going to bigger pilot jets #37.5 cure these following lean/ won't idle- conditions? or should i also go up one size on the mains?

1-Utilized colortune to adjust mixture, all cylinders are blue in color.

2-During adjustment turning mix screws all the way out did not show yellow color only blue to light blue.

3- Plugs show lean condition.

4-idle hangs up at 3000 after warm up.

5- constant adjustment of idle speed screw is needed to get it to idle at 1200-1500 rpm to do adjustments to mixture.

[feelergaugephil]

You have an air leak, most likely the o rings between the cylinder head and intake boots.

[badbrown]

yes check every where for an air leak.. I'm a dumbass beacause I discovered my airbox filter gasket inside the airbox. I never knew about it. I also found my airbox/carb boots way too loose and a couple of them were missing this metal ring that goes inside the boot. I had all kind of idling issues and flat spots in the power band etc.

[GQROD]

yes check every where for an air leak.. I'm a dumbass beacause I discovered my airbox filter gasket inside the airbox. I never knew about it. I also found my airbox/carb boots way too loose and a couple of them were missing this metal ring that goes inside the boot. I had all kind of idling issues and flat spots in the power band etc.

Metal rings inside the boots? i didn't notice any metal rings inside any of the boots, only the ones on the outside which clamp them to the airbox and the intake manifold boot.

As for airbox gasket? where is this gasket supposed to be? i know inside the airbox the air filter is new and has a foam ring bonded to it which goes flush agains the inside of the airbox.

As for intake manifold O -Rings they are new from suzuki.

But all good advice i will keep checking but i will go one higher on the pilots and see where that takes me as well. Thank you all for your advice.

[Suzuki mad]

Standard pilot jets will not cause the bike to idle poorly and run lean unless the jets are blocked and the air screws are set incorrectly or you have an air leak on the seals around the carb.

Have you also checked that you are getting a spark at the plugs?

Suzuki mad.

[MelodicMetalGod]

Metal rings inside the boots? i didn't notice any metal rings inside any of the boots, only the ones on the outside which clamp them to the airbox and the intake manifold boot.

As for airbox gasket? where is this gasket supposed to be? i know inside the airbox the air filter is new and has a foam ring bonded to it which goes flush agains the inside of the airbox.

I'm not aware of any metal rings as mentioned either. badbrown, can you ealaborate? Post a pic?

Standard pilot jets will not cause the bike to idle poorly and run lean unless the jets are blocked and the air screws are set incorrectly or you have an air leak on the seals around the carb.

Have you also checked that you are getting a spark at the plugs?

Suzuki mad.

Is there really no chance that an incorrectly sized (too larger) pilot jet would allow too much air? If so, why are there different sizes available?

GQROD, assuming the pilot air jets are not the issue, since you're still getting an elevated idle after warm-up, it does sound like there's excess air entering the system somewhere. Here's a list of UN-likely things that come to mind: Carb diaphragm, choke plungers - good seals?, is the air filter definitely spec? (not flowing too much air), valve cover gasket (hopefully this is a reach...). There are probably other things that I haven't thought of.

One thing about the air leak idea that doens't make sense to me is that it sounds like you're getting the correct ColorTune flame on all cylinders. If that's the case, then does't it mean that the air/fuel mix in the cylinder is correct?

[GQROD]

I'm not aware of any metal rings as mentioned either. badbrown, can you ealaborate? Post a pic?



Is there really no chance that an incorrectly sized (too larger) pilot jet would allow too much air? If so, why are there different sizes available?

GQROD, assuming the pilot air jets are not the issue, since you're still getting an elevated idle after warm-up, it does sound like there's excess air entering the system somewhere. Here's a list of UN-likely things that come to mind: Carb diaphragm, choke plungers - good seals?, is the air filter definitely spec? (not flowing too much air), valve cover gasket (hopefully this is a reach...). There are probably other things that I haven't thought of.

One thing about the air leak idea that doens't make sense to me is that it sounds like you're getting the correct ColorTune flame on all cylinders. If that's the case, then does't it mean that the air/fuel mix in the cylinder is correct?

That is what i thought , yes i imagine the flame color means correct mix, so i will have to start going through it again to see if there is a leak.
1-Diaphrams were fine when i rebuilt the carbs, no pin holes.
2-Slides were fine unless they are getting stuck which i will check for movement.
3-I will go through the rest of your recomendations to ensure there are no leaks since this makes to me beofre i go changing pilot jets.
4- Air filter is new however it was already inthe bike when i got it. I will have to check part numbers to see if it's oem.
5- I will check the seals again just in case they were defective from the factory.
6- I suspect the charging system may not be working since the new battery died after tuning the bike withteh colortune, total run time maybe 30mins to an hour withthe headlamp on while engine running. So i will test this also.
Thanks again all for your help.

[GQROD]

83GS550E won't idle-update

1-I replaced the choke cable,and starter jet ( O-RINGS...lol ) with a new one from bikebandit.

2-Bike started up right away!, i adjusted the choke cable and the idle speed screw in very small increments this time in order to get a good idle.

3-Idle set at 1200 which held long enough to finally take for a ride around the block a few times.

4-Took carbs out and pilot jets #35 still were clean as was the starter jet fuel tube, none were clogged.

5-Bike after run will not start and will not idle. I believe the battery may be getting drained and not enough voltage is going to coils. I will test charging system to find out for sure.

6-Idle hung up at 2000 rpm during stops this may be more freeplay is needed at throttle cable.

7-I will install #37.5 Pilot jets in order to see if i can get a slightly richer mixture hopefully this will solve the idle problem. I will do plug chops at idle to read plugs and go from there.

[Suzuki mad]

OK you're better than Mr Suzuki.

7-I will install #37.5 Pilot jets in order to see if i can get a slightly richer mixture hopefully this will solve the idle problem. I will do plug chops at idle to read plugs and go from there.

You know better than Mr Suzuki who designed the bike that ran fine originally. Years of research and development into a machine.

Give up the day job and design your own motorcycles.

Suzuki mad

[skreemer]

DON'T replace the pilot jets... If you want no end to jetting issue troubles replace the pilot jets...

Even on the stage 3 full on race jet kits they leave the pilot jets alone.

Clean the heck out of the pilot jet circuit, Make sure your fuel air mix screw passages are clean and the fuel air mix screws are set correctly using the "rough idle method"....

[MelodicMetalGod]

DON'T replace the pilot jets... If you want no end to jetting issue troubles replace the pilot jets...

Even on the stage 3 full on race jet kits they leave the pilot jets alone.

Clean the heck out of the pilot jet circuit, Make sure your fuel air mix screw passages are clean and the fuel air mix screws are set correctly using the "rough idle method"....

Skreemer, if the jetting shouldn't be touched, why are there so many different sizes out there? I ask b/c as part of this I have recently discovered that out of three sets of carbs, each had different sized pilot AIR jets (145, 150, 155).

[Calvin Blackmore]

You know better than Mr Suzuki who designed the bike that ran fine originally. Years of research and development into a machine.

Give up the day job and design your own motorcycles.

Suzuki mad

My Canadian Spec Carbs have OEM supplied 37.5 pilot jets.
NO EPA I suppose?

I do agree that the bike should idle properly if the carbs are clean and have had no alteration to the carbs though. If it does not then it never could have.

[GQROD]

You know better than Mr Suzuki who designed the bike that ran fine originally. Years of research and development into a machine.

Give up the day job and design your own motorcycles.

Suzuki mad

Now that is a real compliment! the reason i was going to change teh pilots is because BassCliff in another thread said these bikes run lean.

1-After the colortune tuning i realized i could not adjust the mixture to get a yellow flame from any of the cylinders the color should be blue as they are now however the plugs show a lean condition, i trust the plugs not the colortune.

2-As such i took the carbs out and cleaned the pilots and starter jet fuel tube again just to make sure, they were all clean already.

3-I took out the plugs and they were grayish to white. So the mix is still too lean.

4-I was going to go to #37.5 pilots and leave the mains alone since these were used on canadian spec models and was told previously this is the setting i should use.

5-I think that either the mixture is too lean or dropping volatage may be the problem so i will take everyones advice before i do anything and see what works.

6- As for not touching the pilots i did read over and over in this and other forums that if you are out of the range of adjustability in the mix that going to smaller or bigger pilots will put the mixture in the correct range to adjust the mix properly. No doubt if i set the jets to factory stock, then to meet emissions regulations the factory may have set the mix really lean to comply with federal emmisons regualtions without regard to future running issues.

7-The bike does run very strong and is smooth in transitioning from idle to WOT. There are small holes in the exhaust though and two of the bolts on the headers had been broken off by the PO leaving only a stud no head, so i'm not sure if this may contribute to teh lean condition. Some backfiring through the mufflers is noted very mild though.

8-Carbs were already synced with the carb tune, however i may do it again as the first time i did it was when the carbs first went on. Just to be on the safe side.

9-Carb mix was adjusted using the rough idle method and double checked with the color tune and plug chops all were lean. This is why i wanted to got up one size only on the pilots and leave everything else alone, but the advice not to touch them makes sense as the problem could lie elsewhere so i will go through it again before i touch the pilots. Just did not want to blow a hole in the piston with a lean condition.

[Zook]

Mr. Suzuki did indeed design the bike well, but the people who think they know better at the EPA made Mr. Suzuki change it.
Besides, with oxygenated fuels the mixtures are now leaner than when the bike was built.

My 90 Guzzi with the OEM jetting was lean on the pilots, went from 48s to 50s, now it idles properly and it wouldn't even run at WFO with 138 mains.
142s solved it and it still gets 48mpg on the slab.

A friend's bike delivered stupendous gas mileage but pinged horribly-it had 125 mains and very small pilots. Rejetted and it's fixed.

The pipes on my recently aquired GS 1000 are also blue-even the mufflers-and they have holes in them from where they have burned through from being hot. Pulled the a/f mixture screw plugs and they were set horribly lean, 1-1.5 turns out. Hopefully just turning them out a bit will make it right. If not, I'll change jets.

[GQROD]

Mr. Suzuki did indeed design the bike well, but the people who think they know better at the EPA made Mr. Suzuki change it.
Besides, with oxygenated fuels the mixtures are now leaner than when the bike was built.

My 90 Guzzi with the OEM jetting was lean on the pilots, went from 48s to 50s, now it idles properly and it wouldn't even run at WFO with 138 mains.
142s solved it and it still gets 48mpg on the slab.

A friend's bike delivered stupendous gas mileage but pinged horribly-it had 125 mains and very small pilots. Rejetted and it's fixed.

The pipes on my recently aquired GS 1000 are also blue-even the mufflers-and they have holes in them from where they have burned through from being hot. Pulled the a/f mixture screw plugs and they were set horribly lean, 1-1.5 turns out. Hopefully just turning them out a bit will make it right. If not, I'll change jets.

Everything yousaid makes complete sense, i know the bike should at least run even if it's lean, but going a little richer within reason as you have done on your guzzi makes sense to keep from blowin the engine.

I'm doing plug chops today at idle and checking the charging system tonight, hopefully i can make more progress and keep everyone updated.