HELP! 1980 GS850G Starts, but stumbles-Pops-won't rev??

[BassCliff]

Hi,

Prices, as of today, for intake boots for my 1980 GS850GT, part#13110-45100 (RH) and 13120-45100 (LH):

G&S Suzuki = $24.22
PartShark = $26.19
CyclePartsNation = $24.94
BikeBandit = $32.82

Documentation for my intake boot replacement:

Air Intake Repair: Airbox removal, intake boots and O-ring replacement

Thank you for your indulgence,

BassCliff

[Darin Jordan]

You guys rock... thanks for the information. It's invaluable to guys like me!

I haven't completely read through BassCliff's welcome yet. Would have likely saved me about $7.00 an intake if I had. Time is sparse... I work on this stuff in spurts of time... between kids and work, and my other hobby... which is racing and developing Remote Control boats for ProBoat Model Boats...

I will take the time to read through it over the next week though.

As for completely cleaning the carbs... Let me get the intake tract completely sealed, and see where I am. I'll pull them completely down if this doesn't work. I have already ordered the complete O-Ring kit, so I'll already have the pieces.

[Ranger]

Call BikeBandit and show them the prices. They have a lowest price guarantee and might credit you the difference.

[TheCafeKid]

Good call, didn't realize that. But still for the time being.... he's not lean

I still doubt thats the cause of his problem. Personally I'd been running stock mains with raised needles and cracked headers at the flange and running lean but completely rideable.

If you're doubting he's lean and it's not his problem you need to get cracking on your carburetor studies. To begin with, CV type carbs ( which any GS built after 1979 came with) are extremely sensitive to changes in air flow. They require air to move the slides. That air flow is dictated by the design of the carb and the airbox it was fitted with. Remove the airbox and you have to compensate in multiple ways for the additional air flow. All circuits except the pilot circuit will be effected by this change. But, to keep it quite simple, you CANNOT jet CV carbs for pods and a pipe by simply changing the main jet size. The stock needles are too fat and slow tapered to compensate for the added air. You will be lean SOMEWHERE if not everywhere past the idle circuit. The bike will continue to fall on it's face somewhere in the rev range. Either get an airbox for it or a dynojet kit. To try to do anything else is folly. A waste of time and WILL cause damage eventually to your combustion chambers and or valves. And this goes for both his bike and yours. "rideable" is a very grey area. If it runs like crap but still rides I suppose it's rideable. For now.

[TheCafeKid]

Btw I meant to add the colour of his plugs mean jack all sitting on choke or idle in the garage. You can't read a plug when there's been no load put on the motor. The idle circuit may be functioning perfectly, but there's still more or less three stages that need tuned beyond that. Brown black tan grey purple. Doesn't matter if it's just sitting there.

[Darin Jordan]

Guys... just to be clear... the bike won't even really rev past idle... it boggs down like it's fuel starved, and just barely is running. Even at idle, it's popping back through the carbs and such, similiar to how it would if the timing were off. I even double checked the spark plug order just to make sure they were hooked up correctly.

I will definitely work on the jetting as you are recommending, but I think that the major issue is likely the air leaking in past the intakes. That ought to get it up off of idle and let it at least run. Once there, I'll absolutely do what you are suggesting and get the thing jetted correctly. Just making sure everything else is correct and not contributing to the problem first.

And, I DO have the factory airbox, with all new rubber bits, but I just wasn't going to use it if I didn't have to. Seems to me that there is better performance to be had by freeing up the intake and jetting accordingly. Making something run "right" by restricting the airflow seems counter-productive to attaining any kind of performance. I'm certainly willing to do the work to make it run right with the Pods... especially if it's worth a few HP....

[TheCafeKid]

I agree you need to check your intake boots for leaks. Airbox or no that will only contribute to the problems. However when you say "make something run right by restricting the air flow" you need to keep in mind that this is not a car. It does t have one carburetor feeding four cylinder or six or whathaveyou. It's got a carb for each cylinder. And those were tuned with the airbox fitted. For each cylinder. The margin for error is sooo much smaller here. Where a car may run ok with a change in air filter or exhaust, these simply will not. I'm not telling you this to make your job more difficult or to disuade you from using the pods. I'm telling you this so you know. You can fiddle fart around with this bike all spring and summer trying to get it right and I'm telling you from years of experience and many many bikes it simply won't ever be right without the jet kit. It's not the jets. It's the needles.

[TheCafeKid]

And btw again. The HP gain from a correctly set up bike with these mods is modest at best. If you've never ridden the thing stock, you're never going to notice. And even then it's so small the headache almost isn't worth it. Remember you have the second heaviest GS ever produced. No slouch mind you as BWringer can tell you, but one ridden well stock will spank a nodded one with a crappy rider. Spend your bucks on fork springs and new shocks. Those will actually save your life. Lol

[Steve]

Guys... just to be clear... the bike won't even really rev past idle... it boggs down like it's fuel starved, and just barely is running. ... And, I DO have the factory airbox, with all new rubber bits, but I just wasn't going to use it if I didn't have to. ...

OK, just to be clear, you do have an airbox. Is it installed?

If you don't have an airbox of any type installed, that is your problem.

If you don't have it installed, do one simple thing for "proof of concept", if you will:
Take a (clean) shop rag, fold it in half. If you have a helper, have them hold it over the carb intakes. If you don't have a helper, use hose clamps or zip-ties to hold the rag to the outer carbs, keeping it taut over the inner carbs. Start the bike. Notice how much BETTER it runs. If everything else is somewhat correct, you can actually take it around the block, but it won't be good enough to do jetting checks.

.

[Darin Jordan]

OK, so are you guys telling me that this thing can't be made to run WELL with K&N Pods, or that it's going to be some needle/jetting work? I can go either way. I have the stock airbox with all the parts, and I now have the K&Ns here as well. I can clean up the stock box, put on the new rubber parts that I have with it, and put it on. I'd really prefer the look of the pods, however. Is it really that much trouble to get them to work?

[Octain]

OK, so are you guys telling me that this thing can't be made to run WELL with K&N Pods, or that it's going to be some needle/jetting work? I can go either way. I have the stock air box with all the parts, and I now have the K&Ns here as well. I can clean up the stock box, put on the new rubber parts that I have with it, and put it on. I'd really prefer the look of the pods, however. Is it really that much trouble to get them to work?

If you run pods and pipe you'll have to rejet if you want the bike to run correct. That's assuming all else is right, IE, o'rings, intakes ect..
Run the stock air box and you wont have to rejet.
My 850 wouldn't even idle right with pods till I installed a DJ kit.

You can restrict the airflow with the pods by partially wrapping em in tape(blue masking) for a temporary fix.

[Darin Jordan]

Alright... I'm feeling beaten into submission here... my vision down in flames... I'll clean up and reinstall the stock airbox for now and see if I can get it running right from there. Reading through my super welcome, it seems even THAT is a finicky proposition. Didn't realize these things were so touchy and sensitive to minor changes.

I've rebuilt the fuel petcock (hopefully THAT is OK... some appear to insist on new ones...), and will make sure the rest of the intake system is correct, install the stock airbox system, and see if/how it runs from there.

[Ranger]

Just get it running, ride it and then eventually throw the pods on. I'll be in Puyallup within the next 3 weeks atleast thats the plan to pick my girlfriends stuff up so she can move down here with me and if you still aren't running right I'll swing by and check.

[Darin Jordan]

Just get it running, ride it and then eventually throw the pods on. I'll be in Puyallup within the next 3 weeks atleast thats the plan to pick my girlfriends stuff up so she can move down here with me and if you still aren't running right I'll swing by and check.

Will do. Thanks.

Quick question... I've been reading up on the DK Dynojet 3 kits... the jets they recommend for a header and pods are DJ165s... cross referencing them, that seems to be HUGE. This jetting kit comes highly recommended here. Can I get this kit and follow the directions (after taking care of everything else you've recommended... ) and have a decent starting point? I'm not adverse to picking up this kit. I want this bike done right.

Also looking at getting my own carb sync tools from Morgan, and the special adjusting wrench, etc... Again, I want to do this right.

[Ranger]

Will do. Thanks.

Quick question... I've been reading up on the DK Dynojet 3 kits... the jets they recommend for a header and pods are DJ165s... cross referencing them, that seems to be HUGE. This jetting kit comes highly recommended here. Can I get this kit and follow the directions (after taking care of everything else you've recommended... ) and have a decent starting point? I'm not adverse to picking up this kit. I want this bike done right.

Also looking at getting my own carb sync tools from Morgan, and the special adjusting wrench, etc... Again, I want to do this right.

They aren't mikuni parts so the #'s on the main are different. Not sure what you came up with for the cross ref. but they shouldnt be bigger than 133. As far as ease of use, yeah if you pay attention when you're drilling for the needle plus it comes with all the stages in it so you can mess around. You should have a good starting point but personally I havent jet my bike and I run pods but thats just me. I did run 135's for a while and my stocks are 122.5 so dont do that unless you love burning fuel and going slow. I raised my needles though and still run lean with my stocks. Morgan carb tune is out of my league, never used it so I couldn't help you there.