pilot jet plug? hmmm!

[kwest187]

1980 GS550 with BS32 carb/pods/open slip on exhaust

Okay I finally got the bike to run-this is after re-shimming valves and moving to a 42.5 pilot...lowering the float height and removing the pilot jet plugs...
The bike ran ok...some needle jet tuning and sync may be in order...
Here's the thing, I put the pilot jet plugs back in after a bench sync and now it won't start again...do I need to go even larger with the pilot jets?...I am running uni-foam pods and a custom exhaust, that still uses the stock headers and Y-pipes, just more open slip-ons.

 

[tom203]

I'd say your enrichment circuit (a.k.a the " choke ") ain't working. If this is functioning, bike should at least start, though it might idle/run like pooh due to other problems. I don't see how those pilot jet plugs have much impact during cranking.

 

[hampshirehog]

Don't try and tune your carbs in by adjusting float height away from standard spec. You'll end up chasing your tail.

 

[Steve]

What exactly are you calling "pilot jet plugs"? :-k
If you are talking about the rubber plugs that go next to the main jets, they HAVE to be in there for the carb to work properly.
Without them, there is a hole that will allow gas to flow besides the main jet, making for some wierd jetting problems.

By "lowering the float height", do you mean that you set them to a lower number? :-k
If so, you actually raised the floats, because your measurement is the amount of drop and you are measuring upside-down.
Raising the floats (by using a smaller number to set them) will richen EVERY circuit while running.
Add that to the pilots that are likely too rich anyway, and it's a wonder your bike will even fire up.

What main jets are you using? With your pods and more-open exhaust, I would suspect that you might need something
in the area of 105 (stock is 92.5), but the stock 40 pilot fuel jets should be adequate.

As hampshirehog said, keep the stock fuel level in the bowls, then tune all your circuits to that.
If your carbs have been properly cleaned and fitted with new o-rings, your idle mixture screws
might need to be about three full turns out, but everything should work just fine.

.

 

[kwest187]

I'm worried about the starting circuit. Thanks to Steve I've checked and set all the valve shims to spec...a couple on the loose side .09mm's. The O-rings I think you're talking about are the ones in the mix screw? If those are the ones...they looked pretty good-but I have no problem buying new ones...I'm sure Ace carries O-rings that size. If you mean the o-rings for the choke, they too appeared good but I can replace them as well. The choke system does work. As I've cleaned and blown through all passages-and have only gotten the bike to start when cold, using the choke. I set the float height to 21 mm. basically to see if I could actually flood the thing-and took the rubber plug out of the pilot jet stem to also do what I could to suck fuel into the intake. This worked. I choked the bike, turned the key, and the bike started. I rode it about 7 miles. I didn't take much note to the richness/bogginess during the ride due to the fact the pilot jet stem plug was out, and the float height. I came back to the shop and put the pilot jet stem plugs back in, the bike would not start. I backed the air screws way out, choked it, and the bike started and ran with the choke out-put choke in and the bike died. I deducted from this that the pilots were still to small.
Also in the tests, the idle was turned in higher than normal running rpm's...
One thing I'd like clarified. The air mix screw (intake side of carb on top) turning it deeper into the carb leans, turning it out richens?...it must b/c I read if you're turned out more than 4 turns...size up the pilot.
So...say the O-rings for the air screw were bad, did leak, wouldn't that give me a rich condition? What role do the O-rings in the choke system play? I know this is a lot, I very much appreciate all the help and advice...I wish I could buy all you guys a beer.
Thanks,
down but not out!

side note-just read a thread about a choke not choking...and it was clarified these Miks run enricheners. during different stages of testing/trials I have noticed when I get the bike to run...I can rev the bike using the choke. Would this be an indication of a working choke/enrichener? ...time for bed...I'll pull the carbs, and take out the choke, pull all O-rings and see if Ace has anything tomorrow..

 

[kwest187]

I AM so so dumb...so dumb...okay so I never read about the intake boot O-ring...never even knew it was there...my boots are in great shape...never even thought about intake boot O-rings...I bet-tomorrow, I pull the intake boots and find old, crappy, cracked leaky intake boot O-rings...
If and when I do...let this be a lesson to the stubborn-geesh-how could've I missed this-

 

[TheCafeKid]

If you didn't replace all the orings, you probably didn't clean your carbs correctly. This is a MUST DO. Period. No short cuts, no half way jobs. That means complete disassembly, soaking the bodies, bowls and brass jets in carb dip for 24 hours each, and blowing all the passages clear with carb spray and compressed air, and cleaning the jet holes and emulsion tube holes with copper wire. Then ALL of the orings must be replaced. These are sealing devices. Either sealing out air or gas. Simply spraying them with carb cleaner will not remove deposits of varnish and crud built up over the years.
You also can't likely pick up these orings at ACE hardware. They're made of nitrile or Buna N rubber which is gas and heat resistant, as well as being specific sizes that aren't widely available. Kits can be purchased thankfully from a very respected and helpful member at www.cycleorings.com.
I'd also suggest replacing the orings that seal the intake boot to the head (also a kit available at the above site) as these flatten and break down over years and air leaks happen here causing the air fuel mix to be too lean. Lean is hot and bad for internal parts such as your valves and can ruin the motor if continuing to run it like this.

Lastly, these carburetors need to be re-jetted to function properly with pod filters and or altered or aftermarket exhaust systems. You cannot simply change the jet sizes as the stock needle is no designed to deliver the required amount of fuel to compensate for the added air flow pods and a pipe or altered exhaust allow. You need to purchase a DynoJet kit for your bike.
But before you bother with that, clean and rebuild your carbs with new orings.

You're way off in your attempt to get the bike sorted out at the moment. There are plenty of us who are more than happy to help you get in the right direction but these steps are necessary, not mere suggestion. So please help us help you and read through BassCliffs and Nessisms tutorials on these things. If you've adjusted your valve clearances that's a step in the right direction, and if you can do that, you'll be quite capable of doing the others as well.
If you need some guidance, feel free to PM me.

Good luck.
TCK

 

[kwest187]

I cleaned the carb fine...I had to separate the carbs to replace one of the bodies...so it all got broken down, dipped, brushed, and blown thru.
I'm running a Dynojet stage 3 jet kit in it, so I'll be able to dial in the jetting fine once it starts properly and I can reset the floats-
I pulled the intake boots off...not so fun getting 30 year old screws out...thats why I like hex heads and allens!
It was apparent that the O-rings there were leaking...I could see where it was pulling past the seal. Also the O-rings were flat, brittle and wouldn't stop a fart...guess its time to go to cyclerings, and order the kit, replace all and finally have GS happiness. Thanks all, and let me know if I'm still missing something-

 

[TheCafeKid]

I cleaned the carb fine...I had to separate the carbs to replace one of the bodies...so it all got broken down, dipped, brushed, and blown thru.
I'm running a Dynojet stage 3 jet kit in it, so I'll be able to dial in the jetting fine once it starts properly and I can reset the floats-
I pulled the intake boots off...not so fun getting 30 year old screws out...thats why I like hex heads and allens!
It was apparent that the O-rings there were leaking...I could see where it was pulling past the seal. Also the O-rings were flat, brittle and wouldn't stop a fart...guess its time to go to cyclerings, and order the kit, replace all and finally have GS happiness. Thanks all, and let me know if I'm still missing something-

Ok, well if youre sure the carbies are clean, and you have addressed both the internal orings and the intake boot orings, try this on for size:

Stock pilot jets (as recommended in the DynoJet instructions)
Make sure your pilot jet plugs are all installed.
Needle clip in the third notch counting UP from the point. (this may need adjusted later, but can be without removing the carbs from the bike)
Pilot mixture screws 3 full turns out from lightly seated (don't forget to put those new little tiny orings on these )
DynoJet stage 3 main jet (the largest main jet in the kit, do NOT confuse this with the accessory pilot air jet replacement they give you which will probably be like a 150 or 160)
Bench sync to assure butterfly valves are approximately the same (search on this if you need help, as it's an important step)
Float level adjusted correctly as per your manual.

Assure that your slide diaphragms are seated correctly with the index nub in the proper place and the diaphragm set in its little channel.
Also double check that these have no pinholes or tears in them. Use a light source behind them so any of these pinholes or such will be apparent.

Once you're certain you've got everything put together correctly, (you'll also want to remove the tubes from the vent tees that go between the carbs when using pods) install the carbs, and prime the bowls with the prime setting on your petcock for a minute or two (watch for leaks from the carbs anywhere). Pull the enrichener lever out to halfway or so (each has it's own "sweet spot" so you may have to play with it) and WItHOUT turning the throttle (opening the throttle destroys the vacuum the enrichener needs) crank the bike. It should start And idle with this set up. It should even ride well. Fine tuning may be needed on the needle clip, and you may find you need to replace the pilot air jet with the one included in the kit but seldom is needed.

 

[kwest187]

Thanks again...one question, why remove the vent tubes from the vent tee's? Honestly I've been using the tubes to drain the fuel from the float bowls before I've pulled the bowls between tests...is there a vacuum reason to remove the Tees? Also I didn't get any air jets from DynoJet...the jets they sent me were the needles and 2 sets of main jets. which are sizes 150 and 155. You said not to get confused with the air jets size 150...I did call DynoJet when I got the kit to ensure the jets they sent me were the main jets to use, and also the air jets and the main jets use diff. thread pitch and diameter...I couldn't screw a main jet into the air jet slot...or vise versa.
Slides are good, the diaphragms are good, bench sync is good-I guess not I sit and wait for new O-rings...

Ok, well if youre sure the carbies are clean, and you have addressed both the internal orings and the intake boot orings, try this on for size:

Stock pilot jets (as recommended in the DynoJet instructions)
Make sure your pilot jet plugs are all installed.
Needle clip in the third notch counting UP from the point. (this may need adjusted later, but can be without removing the carbs from the bike)
Pilot mixture screws 3 full turns out from lightly seated (don't forget to put those new little tiny orings on these )
DynoJet stage 3 main jet (the largest main jet in the kit, do NOT confuse this with the accessory pilot air jet replacement they give you which will probably be like a 150 or 160)
Bench sync to assure butterfly valves are approximately the same (search on this if you need help, as it's an important step)
Float level adjusted correctly as per your manual.

Assure that your slide diaphragms are seated correctly with the index nub in the proper place and the diaphragm set in its little channel.
Also double check that these have no pinholes or tears in them. Use a light source behind them so any of these pinholes or such will be apparent.

Once you're certain you've got everything put together correctly, (you'll also want to remove the tubes from the vent tees that go between the carbs when using pods) install the carbs, and prime the bowls with the prime setting on your petcock for a minute or two (watch for leaks from the carbs anywhere). Pull the enrichener lever out to halfway or so (each has it's own "sweet spot" so you may have to play with it) and WItHOUT turning the throttle (opening the throttle destroys the vacuum the enrichener needs) crank the bike. It should start And idle with this set up. It should even ride well. Fine tuning may be needed on the needle clip, and you may find you need to replace the pilot air jet with the one included in the kit but seldom is needed.

 

[kwest187]

Just ordered the entire kaboozle...Complete BS carb O-ring set, Intake O-rings, and the stainless hardware...
and yeah if I didn't state it earlier...the phillips heads are horrible to get out...it took me about a hour and a half to remove all eight. I used the impact screw driver for the ones I could reach, two different sizes of vice grips, lots and lots of PB, the lower inside two were the hardest...IF YOU have your motor out...pull these bolts NOW and save yourself hardship-