82 GS850GLZ will not rev out.

[Mercaholic]

Could it be a plugged exhaust? Seems like that is all that's left.

I'm with you on this one

[79xs]

You never have answered the question whether you have the stock airbox, pods or even anything on the intake of the carbs.

You can put as many different sets of carb on there as you want. If they don't have some restriction in front of them, they will ALL run like crap.




If this is, indeed, your 15th+ set of Mikuni CV carbs, you should be well aware that the "choke" does not "dump" fuel into the system. The ENRICHENER system (what you are calling "choke") relies on a CLOSED throttle butterfly to have enough vacuum to pull a measured amount of fuel through the enrichener fuel tube (the skinny tube that sticks down into the edge of the float bowl cover) and the air passage that comes from under the diaphragm. Only by varying the amount that you move the ENRICHENER control lever (or knob) can you adjust your mixture to start your cold engine. If you open the throttle AT ALL, you destroy the vacuum that is necessary to activate the ENRICHENER system.

.

I understand how it works.. you are looking into it a little too deep though.. It stills pulls enough fuel to overcome what the pilot system does on the bike. thats why i'm saying that cleaning the pilot jets and air passages another 100 times won't help me until I can get the bike to rev out. I just don't care about how well it idles right now.. or how fast it responds to throttle.. I'm worried about the fact that it falls flat on its face after 4000 rpm in neutral on the center stand...no matter how i work the throttle. I also covered the back of each carb with my hand as I reved up to bike to force it to take fuel.

[79xs]

Very very odd...


I put the valve cover back on. I sat there looking at the bike drinking a PBR then I recalled another post talking about a coil relay mod.. so I thought I would double check the voltage to the coils. It showed only 9 volts at the coils and 12.10 at the battery. I did not have a headight connected when I did all my first readings last week. So I disconnected the headlight using the plug located near the right side coil. This brought the coils up to around 10.9... The bike started up and ran almost perfect ...it reved right up to 8. Very little hanging idle.. the odd part is that I reconnected the headlight and it kept running fine. I have a feeling there are some wiring gremlins hiding out.

[cowboyup3371]

Maybe I missed something but is the air filter on or are you using pods?

[psyguy]

I also covered the back of each carb with my hand as I reved up to bike to force it to take fuel.

Cant really see what this means. You do have the airbox on

[79xs]

Yes, the airbox has been on and off. I left it installed once I knew the carbs didn't seem to be my problem. In one of my posts I explained that I ran another leak test on the carbs and the airbox, they haven't been off since then. Either way, the bike is doing a lot better since I messed with the wiring. I'm going to install that relay mod tonight.

[Nessism]

Yes, the airbox has been on and off. I left it installed once I knew the carbs didn't seem to be my problem. In one of my posts I explained that I ran another leak test on the carbs and the airbox, they haven't been off since then. Either way, the bike is doing a lot better since I messed with the wiring. I'm going to install that relay mod tonight.

Not sure if you realize but the GS family of bikes won't run for crap with stock jetting unless the airbox is installed, all the boots are properly sealed, the filter is inside the airbox, and the end caps on the airbox are sealed with fresh foam. The system is very sensitive.

A hanging idle is often a result of an intake problem, lean running. Spraying WD-40 and the like around the engine has proven to be ineffective on GS bikes so keep this in mind for the future. Where are the pilot screws adjusted? Most GS's run best with 2.5 turns open, some require more. A poor sync job can also cause a hanging idle.


Good luck, hope you figure it out soon.

[RipRoaringFun]

Not sure if you realize but the GS family of bikes won't run for crap with stock jetting unless the airbox is installed, all the boots are properly sealed, the filter is inside the airbox, and the end caps on the airbox are sealed with fresh foam. The system is very sensitive.

A hanging idle is often a result of an intake problem, lean running. Spraying WD-40 and the like around the engine has proven to be ineffective on GS bikes so keep this in mind for the future. Where are the pilot screws adjusted? Most GS's run best with 2.5 turns open, some require more. A poor sync job can also cause a hanging idle.


Good luck, hope you figure it out soon.

Question -- does the 1981 gs1100Ex have a sync adjustment?
Also: could a bad pilot screw adjustment (the screw at the top front intake side on each carb) could a bad pilot screw adjustment cause white plugs (lean/too hot)?

[Nessism]

Question -- does the 1981 gs1100Ex have a sync adjustment?
Also: could a bad pilot screw adjustment (the screw at the top front intake side on each carb) could a bad pilot screw adjustment cause white plugs (lean/too hot)?

Yes of course it has a sync. Don't you have a manual for your bike? If not, basscliff's site has a link so you can download one for free.

Misadjusted pilot screws won't cause white plugs since the adjustment is just for the low speed/idle circuit.

[RipRoaringFun]

Yes of course it has a sync. Don't you have a manual for your bike? If not, basscliff's site has a link so you can download one for free.

Misadjusted pilot screws won't cause white plugs since the adjustment is just for the low speed/idle circuit.

I just found the synchronization in the manual, I searched for 'synchronize' and 'synch' but it's listed as 'Balancing' go figure.

Question for you -- is it possible that misadjusted pilot screws would cause a high idle that sloooowly drops down? And do you think my exposed air filter shown below is the source of a 'leak' ?

[Suzuki_Don]

Your symptom sounds more like am air leak to me. The breathing will be different (different air flow) with the setup that you have. The jets in the carbs are for the standard airbox and aircleaner setup. If you alter this as you have done then expext to rejet.

[Nessism]

Dude, you are threadjacking here. You might want to consider starting your own thread.

Oh, with the back half of the airbox missing the carbs will have to be rejetted or the bike won't run right.

[RipRoaringFun]

Dude, you are threadjacking here. You might want to consider starting your own thread.

Oh, with the back half of the airbox missing the carbs will have to be rejetted or the bike won't run right.

Sorry if I offended you. I knew *full well* what I was doing with the question -- it's always a good thing that users search the forum to see if there are related posts/threads already out there -- so I spent a fair chunk of time doing that -- and discovered, after spending time searching the database of past posts -- I found you discussing *exactly* what I sought help for.

I reasoned 'well it's probably Okay to pose one question to this guy who seems quite knowledgeable about this problem I have in this thread' and 'thread jacking' to me means creating a new sub-thread (not just one question like mine) in an existing thread.

Next time I wont even post a question like this, should I just send a direct email to that person? The sensitivity to this is all over the map on the bike forums on the web, did not think one question would be offensive. And I did start a thread btw, but also searched the database, and that's just making full use of the board here I reckon.

[cowboyup3371]

Rip, it's best to start a new thread even if the subject is similar since 1) the original poster's question and points can get lost in the second discussion, and 2) you may not get the full service you need especially if something is different - especially since the original question was concerning an 850 and you asked about an 1100 with different settings. If you'd rather not, then at least keep an eye on the thread you found in case the information offered up to the OP relates to yours as well.

[Nessism]

Sorry if I offended you. I knew *full well* what I was doing with the question -- it's always a good thing that users search the forum to see if there are related posts/threads already out there -- so I spent a fair chunk of time doing that -- and discovered, after spending time searching the database of past posts -- I found you discussing *exactly* what I sought help for.

I reasoned 'well it's probably Okay to pose one question to this guy who seems quite knowledgeable about this problem I have in this thread' and 'thread jacking' to me means creating a new sub-thread (not just one question like mine) in an existing thread.

Next time I wont even post a question like this, should I just send a direct email to that person? The sensitivity to this is all over the map on the bike forums on the web, did not think one question would be offensive. And I did start a thread btw, but also searched the database, and that's just making full use of the board here I reckon.

I'm one of the grumps around here regarding people posting repetitious threads and thread jacking, but no harm done here. Honestly, there are hundreds of threads here detailing the importance of keeping the bike stock otherwise the need to rejet the carbs, and of course carb sync is necessary.

You have a 30 year old motorcycle that needs maintenance. Rebuild the carbs, replace all O-rings inside the carbs and on the intake boots, sync the carbs, set the pilot screws to 2.5 turns open and then tune from there based on achieving the highest idle, adjust the valves, etc. This is all basic maintenance that should be done before the bike is allowed to leave the garage in my view.

All this info is in the archives so don't be afraid to search. Use Titles Only in the advance search feature to really hone in on the topic you are interested in. Post new threads when you can't find the answer after searching. And no short cuts allowed in the maintenance unless you don't care about getting stranded somewhere.