How to baffle the Rocketman?

[Jethro]

I wrestled with what I thought were carb issues for MONTHS when finally I installed a lead to the coils directly from the battery with a relay. Additionally, my carb boots were cracked, but testing with water, WD40 and even carb spray (not recommended) showed no change in idle. Even after I took them off I thought they were fine, but squishing them showed major cracks. Also, check your ignition advance unit. This needs to be lubed up occasionally.

[Jethro]

There are 12 inch lbs in 1 ft lb.

Best website ever (I actually had to check the above):

http://www.onlineconversion.com/

Here is the torque page: http://www.onlineconversion.com/torque.htm

[Rocketman]

I didn't know the calculation was that simple. Thanks. Also, I already replaced the stock ignition pickup with a new Dyna S, when I replaced the coils, and wires back in June or July. The Dyna has 2 pickups in it, and its really brand new. Don't know about lubing it, but spark so far has not been a problem. If it were, I think it would effect two cylinders simultaneously through either coil, and that hasn't been a sympton. Let's see what the new o-rings bring as several others suggested same, that spraying them up yielded no results, but replacing them did. Lastly, I'm going to pack up that air box with everything short of self-expanding foam to see how that works. Right now I just have the oiled foam air filter sandwiched in the cage, but no side foam at all. The side covers are snug on the airbox, and I can't imagine any excess air getting in, but I'll do the weather-stripping thing just to make sure. I asked this the other day, but, if the o-rings cure my migratory cold cylinder problem (and I can only pray it is so) will carbs have to be re-synced and idle mixtures adjusted again, or not.

[rustybronco]

If my math memories are correct...you divide the inch-pounds by 12 or multiply foot-pounds by 12.

You got it!

p.s. 1 lb on a 1 foot long lever or 12 inch lever = same

[bwringer]

...Lastly, I'm going to pack up that air box with everything short of self-expanding foam to see how that works. Right now I just have the oiled foam air filter sandwiched in the cage, but no side foam at all. The side covers are snug on the airbox, and I can't imagine any excess air getting in, but I'll do the weather-stripping thing just to make sure. I asked this the other day, but, if the o-rings cure my migratory cold cylinder problem (and I can only pray it is so) will carbs have to be re-synced and idle mixtures adjusted again, or not.

Yes, sealing the airbox will make a HUGE difference. You absolutely can't get an 850 to run right without properly sealing the airbox. I know it seems like those side covers are tight, but they leak plenty of excess air without good foam seals.

Also, make sure there's foam weatherstripping sealing the top of the air filter cage.

And yes, you should re-sync the carbs after all this and adjust the idle mixtures. All these calibrations will probably be off. You'll find that the calibrations are much easier to do when you're not leaking random excess amounts of air into the intake. Unless they're way off, it should start and run pretty quickly.

I'd start with all the idle screws 2.5 turns out. You may need to open them up a bit more to get a nice smooth off-idle transition. Again, with the air leaks handled, you'll find that the fine-tuning finally makes a difference. Set all the idle screws the same, then do a carb sync and fine-tune from there.

I've never been able to fine-tune the idle mixture screws by ear with the bike just sitting there running -- I have to go ride it to see what it feels like under closed throttle and off idle conditions. I generally set all the screws the same, then change them in 1/4 to 1/2 turn increments until I'm happy with the throttle response, etc. Some say you should set the inner two a wee bit richer by 1/2 to 1/4 turn, but I've never been able to tell if that really makes any difference.

[Rocketman]

2007 The Baffling of Rocketman from 2006 continues.....

Latest update for the veterans who tried to help me through my trials and tribulations last year, and maybe some newbie blood from this year could help: To summarize: 1982 GS850L 13,000 original miles: sat in my garage for past 8 years and resurrected this past Summer after all old shellaqued fuel etc was cleaned & blown out (trust me, I've been through dozens of new tanks of gas since, there's no more old crap even near this bike much less still in it): latest updates since June 2006:
New: Accel coils, spark plugs & wires & boots; new Dyna S ignition pickup; new battery; new petcock (I mean BRAND NEW!); new intake boots & intake O-rings (as per BWRINGER's request), completely rebuilt and cleaned beyond belief carbs 5 times from the ground up; re-packed air cleaner, nice and tight with side panels of 2-1/2 -> 3" foam glued in, about as airtight as my wallet!; new fuel lines & vacuum lines; shiny clean silver gas tank guts; no crud in any screens or ports in carbs or anywhere else for that mattter; checked every ground and every connection on the bike wire harnesses for shorts, etc, everything is freakin' perfect. Last time compression was checked, prior to intake boots & o-rings being replaced, cylinders were within 10-15 psi of each other, and carbs have been re-synched twice. Same problem persists....Cylinder #1 is relatively cold in relation to other 3 cylinders which are "melt your skin off" hot after warm up. (At least the cold cylinder stopped migrating randomly for now). Tried swapping wires #1 with #4 just for kicks and no change; cylinder #1 is still luke warm, nowhere near like the others. Now the combustion engine basics....fuel, air & spark have been identified, and all components either repaired, rebuilt or replaced. Still get strong blue spark when I pull plug #1 and ground it to the head, and plenty of fuel in bowl #1 when I drop the bowl screw, but the plug is still tannish whiteish light brown, and dry, not soaking wet like I would have aniticipated it would be since it doesn't appear to even be firing. Don't believe I have any lack of fuel, or excess air at this point. With only 13,000 miles and good compression, no backfires, and no stinky exhaust, etc I've pretty much eliminated rings, valves, etc as potential problems (at least I hope I should have? If valves werre either stuck open or closed, would that cause this problem????) . Now..... the West Virginia get-together is not too far off, and I was told that whether I come there from New York on a 3-cylinder GS850, or my (almost brand new) 2002 BMW R1200c (which should be arriving tomorrow), either way, either bike would be considered "a conversation piece". As I'd much prefer to attend a GS rally on MY GS, any further advice as to curing the case of the cold cylinder would (as always) be appreciated. Plus a trip that long on 3 cylinders would probably blow piston #1 through the engine, killing me on explosion or impact, and that would just plain rot. What obvious thing am I missing here guys? For prior suggestions, please see threads going back to the beginning. Thanks, Larry.

[Kabonkie]

You know Larry this is going to sound like the dumbest of requests considering every thing you've already done. But let's try....

Swap the plugs from #1 to another and see if the cold cylinder follows the plug. It's still firing, just not as hot as the others, hence the tan color. And as a suggestion, just do one thing at a time. If you keep pulling and repairing, you'll never find the problem, or at least know what it was.

Glad to finally hear the BMW is about to arrive. Geeze, how has your wife put up with you for the past month? And this must be like getting a late Christmas present.

[ard]

carb

Hi Rocketman, I went through the same problems with few of my bikes, what I am going to tell you may not cure your problem, however it is worth to check; I pulled my carbs few times and clean them good (I thought) the problem did not go away until I pulled the carbs one more time thanks to someone on the TGR. explaining the function of the PILOT JET, I think your problem is your pilot jets, go check the out, make sure the center hole in the pilot jet is open, that is where your fuel coming when your bike is ideling.and I hope it works for you, until that point everything and almost everyone was pointing to the electrical Ignition,

ard

[Dink]

Umm have you checked valve clearences??

Dink

[oilheadron]

My '82 GS1100GK, also with about 13k miles, was doing almost exactly the same thing as yours, and this after the same exhaustive search through everything we could think of. Here's what we found:

1. If you are running standard NGK spark plugs: They are COMPLETE crap. We've seen this over and over again during the past year or so in our shop. We won't install them any more. It seems like they've cheapened the hell out of them to enhance the $ale$ of their premium plug$ (that's my conspiracy theory anyway). So...

2. Get some Denso iridiums, can't remember the correct plug at the moment but these will outperform the standard NGK junk by MILES (as well as pretty much anything else out there). Then...

3. Check the i.d. of the main jets or simply replace them with new stock ones (sorry if you already have, I didn't have the time to read all the posts). Mine had stock mains in it, but they had been drilled out slightly in the past and this ALONE was enough to cause almost exactly the same symptoms your bike is showing.

Good luck.

[Rocketman]

To Kabonkie: Already tried swapping plugs individually and the complete set of 4, and no change. P.S. Can't believe the beemer is finally on its way. Supposed to arrive 12:00 today. You probably have no idea how I've been sitting on pins and needles for the past month waiting.

(2) Oilheadron: appreciate the NGK plug advice, but that probably wouldn't explain the other 3 cylinders working fine. Plus when I pull plug #1, I'm already getting plenty of spark.

(3) Dink and Ard: Will have mechanic check valve clearances next, and re-check pilot jet.

[oilheadron]

The NGKs can appear to the eye to be firing fine outside of the motor, but put 'em back in and they can't handle combustion pressures. We've seen this happen several times and in several different bikes. Once they get fouled to any degree they just won't come back to full function, even if they seem to have good color. Total junk.

The valve adjustment suggestion is a real good idea too.

[Dink]

My '82 GS1100GK, also with about 13k miles, was doing almost exactly the same thing as yours, and this after the same exhaustive search through everything we could think of. Here's what we found:

1. If you are running standard NGK spark plugs: They are COMPLETE crap. We've seen this over and over again during the past year or so in our shop. We won't install them any more. It seems like they've cheapened the hell out of them to enhance the $ale$ of their premium plug$ (that's my conspiracy theory anyway). So...

2. Get some Denso iridiums, can't remember the correct plug at the moment but these will outperform the standard NGK junk by MILES (as well as pretty much anything else out there). Then...

3. Check the i.d. of the main jets or simply replace them with new stock ones (sorry if you already have, I didn't have the time to read all the posts). Mine had stock mains in it, but they had been drilled out slightly in the past and this ALONE was enough to cause almost exactly the same symptoms your bike is showing.

Good luck.

I have been saying this for years!!! Ever since I had to buy 10 NGK plugs to get two that fired, I bought EVERY plug of the type my bike took within 25 miles of my home; cost my parents some fuel too , as I was still at home, I told our local NGK rep this and he sent me a FREE set of Iridium plugs TWO of which have since failed, BUT you would not believe how hard it is to buy anything except NGK here.

Dink

[Rocketman]

Great advice guys, and I really do appreciate it, and will try any and all suggestions. Now that my "new" BMW finally arrived this morning, the pressure is kind of off me to at least have a running bike. I think I'm going to drop the bike off at a new mechanic (with a set of new eyes) and if he has to keep the bike all winter that's fine, so long as I get it back running on all 4 cylinders. At the risk of hopefully not ****ing him off, I've printed out the entire thread of my saga, with all your suggestions, and will let him run through them and try everything. I'll update you once eberything is back in order.

Thanks again,
Larry

[bwringer]

I searched through this whole thread, and as far as I can tell, you have not yet actually checked/adjusted the valve clearances.

All 8 valves require clearances between .03mm and .08mm. Please note -- those measurements are in hundredths of millimeters, not thousands of an inch. You can get a metric feeler gauge in most auto parts stores.

Those valve clearances are vanishingly small, and they are critical. If they've never been checked on this bike, they are definitely way out of whack. The manual calls for a valve check/adjust every 4,000 miles. They don't normally change fast, but they do change and must be checked -- I usually need to adjust one or two valves at every other check.



Also, FWIW, I've never seen a bad NGK plug in a car or motorcycle. I replace the B8-ES plugs on my bike every year or two, so they usually see something like 12,000 to 20,000 miles on a set. I've never had a plug-related hiccup. I have had other brands of plugs (AC, Champion, Bosch) fail in cars, but not an NGK. Maybe I'm just lucky, YMMV, and other disclaimers as needed. And maybe we get better plugs here in Indiana than the rest of the world. Who knows?