Frustrated - Help!

[flyingace]

At this point, I wouldnt be able to ride the bike for 10 minutes. Last night I got it to the point where it would warm up, start without choke, and idle fairly well. Once you get on the throttle though, it bogs down. Seems to be about 1/8 throttle. Also, the bike is getting pretty hot, which I take to mean its running lean.

When I bought the bike, the PO knew less about it than I do. He had the carbs off a 750 (I think...) on it with pods, and it wasnt running worth squat. I replaced the carbs with the correct ones, and the symptoms I'm getting now seem to be a result of those pods. I figure my options now are to buy an airbox or rejet the carbs, but I dont know what to rejet them to...

Those CV carbs are designed to work with the stock airbox. Once you start going down the rejetting path, you are doomed to hours of tuning and retuning and still the bike won't run as well throughout the rev range as stock. Some will disagree, but my 850 is box stock - it idles perfectly and has no flat spots and runs strong to redline.

[rustybronco]

1982 GS 850 GZ this morning 10,500 in 1st, 8,500+ (ish) in 2nd not a miss...
oh stock air box.
I'd rather ride it.

[BigDaddyKool]

I think your getting too much air with the pods you have. My 850 did the same thing, so i did some experimenting and im in the process of building my own unique setup which will have the rubber stacks from the airbox with some goodies mounted inside and filter capability. The only thing you will be able to see will be the boot stack coming off the back. I'll be done on monday I will post pics. Mine rips to redline like a raped ape and idles perfect with a custom setup I made. Monday it'll be here.

[bwringer]

Those CV carbs are designed to work with the stock airbox. Once you start going down the rejetting path, you are doomed to hours of tuning and retuning and still the bike won't run as well throughout the rev range as stock. Some will disagree, but my 850 is box stock - it idles perfectly and has no flat spots and runs strong to redline.

Ditto here!


You are running so lean that it isn't even funny and it certainly isn't good for the bike. Stop overheating the poor thing until you get the correct components to change the current stock jetting or install a stock airbox.

I would highly recommend that you git yerself an airbox and seal its side covers well. Once you experience a well-running 850, you won't want to keep piffling around with pods.

With the stock exhaust, there's little point to trying to use pods anyway. All you'll get is a foul-tempered, anemic beast.

If you must, and if you have an aftermarket exhaust, you'll need to do some experimenting to get the correct jets and shim and/or replace the needles. The kit mentioned is a good starting point IF you have an aftermarket exhaust. You can still plan on taking the carbs off about 278 times.

[Grif]

Well, Ive more or less decided I dont want to jack with the pods anymore. I found a decent looking airbox for a GS1100 at the salvage shop up the road, and the guy who runs it seems to think itll work on my 850.

Can anyone confirm, is an 1100 airbox similar to an 850 airbox, or is it designed for more airflow due to the bigger engine?

[KEITH KRAUSE]

Your jetting probably is wrong but you can't re-jet until the basics are checked.
You said you believe the fuel isn't flowing well through the petcock but don't say anything else after that. If the screen is clean as you say, then take the front apart and check inside for any clogging. If OK, then check the diaphragm operation and inspect. You have to verify good fuel flow.
Next, you said there's white smoke coming out the pipes. Sounds like you're burning oil to me. Oil kills good combustion. Your compression may also be poor. Compression must be checked for being within specs and the oil leaking must be repaired before any re-jet.
Pods can be difficult to jet, but don't blame them for what appears to be other problems.

[Grif]

The petcock looks good, I think I was just expecting a greater amount of fuel flow than actually occurs.

The white smoke only occurs after the engine has been running a while at full choke with throttle. It smells rich, like too much gas rather than burning oil, and doesnt occur when the choke isnt used.

Still no joy on the 1100/850 airbox comparison?

[Road_Clam]

2 months of work, the 850 is still down, and Im about at my wits end.
Here's the symptoms as I see them, but if you can think of something I'm about ready to try anything.

We rebuilt the carbs. They're spotless clean with 115 mains and 180 air jets. The carbs are podded (previous owner...) if that helps. Diaphragms are all firmly seated, and everything looks good as far as I can tell.

I dissolved a good bit of a bad Kreme job out of the tank and flushed quite a lot of crap out with Berrymans B12. The petcock filter looks clean, but gas is still coming out slower than I think it should. Might be part of the problem?

The bike will grumble a little when the button is pressed, but not actually start without choke. Give it choke and she roars to life. After a bit at full choke, white smoke starts coming out the pipes and the engine gets really warm. Let off the choke and it dies. Restart with choke and it idles fine, give it gas for a while and it seems to run fine. After a certain point though, it sounds like its bogging down and dying, even with choke.

Anyway, any ideas would be great. I'm more than happy to give more thorough descriptions if itll help.

Thanks,

Let me fill you in on my carb grief that I went through this past winter. I have a feeling you will find you have the same problem I did. I installed a Dynojet stage 1 kit, and I added a good free flowing 4 into 1 exhaust. My initial jetting was Dynafet needles (quite a bit thinner than stock), 114 mains, and stock #45 pilots. air screws 2.5 turns out. My bike would start, but run rough, would run better with the choke. As for off idle, alls my bike would do was quickly die when trying to introduce throttle. To make a VERY long story short, my 1100 was simply WAY over jetted. I yanked the Dynajet needles, and replaced them with the stock needles with the addition of a "1/2 shim", and now my bike would rev up much better. I am still finalizing jetting, as I even leaned out my bike a bit more by stepping down the 110 mains, and my bike runs perfect on top end. I still have a slightly lean pilot circut, than eventually goes away after about 1/2 hour of running. I need to step up to #50 pilots (i'm just too lazy right now). So try leaning out your mains and see what happens. I'ts worth a try, and you will be able to tell right away if you are moving in the right direction as far as jetting.

[rustybronco]

Can anyone confirm, is an 1100 airbox similar to an 850 airbox, or is it designed for more airflow due to the bigger engine?

What year and model?
or snap a picture and post it on here.

[KEITH KRAUSE]

White smoke from a warmed up/hot motor is oil burning, not a rich condition.
Darker/black exhaust comes from a rich mixture.
You said the bike needs choke to continue running and it also doesn't accept throttle past 1/8. Both of these suggest a lean condition. Yes, a rich or lean condition can cause bogging, but when choking helps the bike run better it's because it's lean. Also, a correctly jetted bike will die if given choke after it's fully warmed up. If yours runs at all, let alone better, the added choke is helping a lean condition. Just going by your description.
If you're POSITIVE the diaphragms are seated correctly and can't be leaking/cracked/torn (only takes one to cause bogging/accept no throttle), then I'd re-bench synch the carbs and follow that with a vacuum tool synch ASAP. Re-tune the mixture screws for best idle when the bike runs well.
Remove the floatbowl vent lines and leave the ports open.
Check/adjust float levels. Be sure the pilot and primary air jets (filter side of carb throat) are clean along with all other jets/passages.
Intake leaks could also be a factor here.
I think you've missed something during your inspection/work.
The main jet has nothing to do with throttle position under 3/4. Your problem is not related to a large main jet.
As for jetting, what brand pods and pipe do you have? If you bought a jet kit, what brand and stage is it?

[rustybronco]

http://cgi.ebay.com/ebaymotors/Airbox-w-chrome-covers-for-1980-Suzuki-GS-850-GS850_W0QQcmdZViewItemQQcategoryZ35597QQitemZ4638698681QQrdZ1

[hungryman]

When you rebuilt the carbs, did you blow out all of the passages with compressed air?