Running terrible after oil change. What?

[GSXTommy]

Hi.

You say 10/40 oil ? isn`t that car oil ?
you say you also drained the oil from the nut on the oilpan, filled up to the cap. wel. the oil shall be half way on the oil glass/cap and not up to the edge to it.

it can also be the oil pump, the oil light tells you also that the engine got no oil pressure I belife.

the producers say that you must use the oil to the bike and never use oil that you by at you local store, I think the 10/40 oil are thicker than then oil that you shall use.

Maby Im wrong, just a suggestion.

[marcopasco39]

Well thanks for your help anyways. I think I'm going to do a valve adjustment, change the oil and filter again. And make sure the carbs are all squared away. I don't know what else to do.

[Mysuzyq]

I am not worried about my carbs right now kdo, I'm going to put filters on them. I'm more concerned about why my motor sounds like it has rocks in the head and my oil light came on when i changed my oil.

The PO may have used 20W-50 oil to mask some issues, and dampen some odd sounds that are more apparent with 10-40. I don't really see a reason to run 20W-50, at least in your location. Maybe drain the oil again and use 20W-50 to see if it sounds better, to confirm. I think the illuminated side-stand light may just be some issue with the switch...possibly got disturbed whilst doing the oil change.
I would deal with the ongoing issue first, before proceeding with valves etc.....if any additional symptoms come up, multiple inputs make trouble-shooting more difficult.

[cowboyup3371]

Hi.

You say 10/40 oil ? isn`t that car oil ?
you say you also drained the oil from the nut on the oilpan, filled up to the cap. wel. the oil shall be half way on the oil glass/cap and not up to the edge to it.
the producers say that you must use the oil to the bike and never use oil that you by at you local store, I think the 10/40 oil are thicker than then oil that you shall use.

Maby Im wrong, just a suggestion.

Actually my 81 550T requires use of 10w40 oil that I buy from the motorcycle shop. Others around here use the Rotella 15w40 like what you'd use in a diesel engine. Only thing to worry about is not using the 10w40 oil made for autos that you buy from Oreilly's or Autozone.

[Larry D]

I recently acquired an 82 GS1100GL w/ 31k miles. It doesn't have any air filter on the carbs but I cleaned all of the carbs completely, set the screws, cleaned the tank, charged the battery. It started right up, ran very smooth with steady idle and I rode it around a little. I knew it had 20w-50 oil in it. So I drained the oil and put 3.6qrts of 10w-40 in. Now the motor makes a lot of noise, it idles sporadically and wants to die. Then the oil light comes on. All I did was drain the old oil and put 10w-40 in. Please help.

With all things being right, the bike SHOULD have run like crap with no airbox on it. The fact that it ran very smooth with a steady idle is odd.

So, my question is, does it have the airboxes and all it's missing is the air filter -or- are you running it with the carbs just flapping in the breeze ? Also, how did you clean the carbs and set the screws ? Did you dissassemble them and dip or just spray some cleaner in there ? Which screws are you talking about ?

I'm thinking that it is now running poorly as it should have before you changed the oil and the oil change had nothing to do with it at all.

[marcopasco39]

My carbs are flappin in the wind haha. And yea i stripped them all apart and used brake cleaner on all passages and blew them out. I turned the idle mixture screws out 2 turns from lightly seated. I was also thinking thqat maybe the thicker 20-50 was dampening some engine noise as well. i guess i will put 20-50 back in it and see if that does anything.

[Larry D]

My carbs are flappin in the wind haha. And yea i stripped them all apart and used brake cleaner on all passages and blew them out. I turned the idle mixture screws out 2 turns from lightly seated. I was also thinking thqat maybe the thicker 20-50 was dampening some engine noise as well. i guess i will put 20-50 back in it and see if that does anything.

Brake cleaner is for brakes.........You should do this. Completely disassemble, dip each carb for 24 hrs in a can of Berrymans, reassemble using new o-rings from cycleorings.com.

http://www.thegsresources.com/gs_carbrebuild.htm

The two turns out sound good, I usually go about 2 1/2.

You SHOULD be running very lean with no airbox at all. Be careful with that, bad things can happen.

Before changing the oil, try this. Take some socks or an t-shirt and wrap the carbs to restrict the airflow some and see if it runs a little better. Of course, this isn't a permanent fix. If you're planning to go with pods, re-jetting will be required.

[MikeJ]

I am not worried about my carbs right now kdo, I'm going to put filters on them. I'm more concerned about why my motor sounds like it has rocks in the head and my oil light came on when i changed my oil.

Putting aside all the other stuff you wrote originally, and which other GSers have commented on at length, I think the above has a very simple explanation. Your newly acquired liter-class GS with well over 30,000 miles on it may not have been as well cared for in the past as some other GS's which seem to last forever if treated right - its engine may already be in need of teardown and overhaul.

Maybe PO didn't change the oil often enough, or did something else to abuse the engine (drag racing??) and to make it wear out prematurely, which increases the clearances between its moving parts - and then he started using the heavier 20w-50 oil because clearances inside the engine were way looser than they were supposed to be, and the thicker lubricant "filled in" those excessive gaps and let the bike appear to run halfway decently. That's why foax with high-mileage older-model cars used to put STP or other super-thick oil treatment into their oil. (Most newer cars are built to much tighter internal engine tolerances and are designed to use much thinner oil for their lifetime than old cars were.)

When you switched back to 10w-40 the lighter oil opened up those clearances again, meaning possibly - more clattering and noise, less compression, poorer valve operation and timing, or all of the above. That also may explain why your oil light came on - much lower oil pressure, even with the engine running. Partly that's due just to the thinner oil, but maybe your oil pump is worn out too, and it can't pressurize the thinner oil enough to fully open the gap in the idiot-light oil-pressure sensor unit and prevent the light from flickering.

It's also possible that, if you used regular car oil instead of oil intended for wet-clutch motorcycles (or diesel oil such as Rotella-T) the lack of all those wear-preventing and gap-filling additives that old motorcycle engines require may have made the problem even worse than merely the thinner viscosity rating of 10W-40 alone would have caused. Your clutch will slip, and your internal parts will rattle even more, if you used oil intended for a modern, catalyst-equipped car. The oil makers took all that good stuff bikes need _out_ of modern car oil because it gummed up the emissions control catalysts, and that's why newer cars _had_ to be built to tighter internal tolerances and use thinner oil. That's also why diesel oil is still OK to use for old bikes - diesels don't have catalytic converters on them.

Changing back to 20w-50 isn't going to solve your problem, though. It's just going to mask the noise again as its cause continues to get worse, if what I suspect about Previous Owner is true.

[Clone]

I have heard that not so reputable folks will put 20/50 or straight 50 in a motor even shoot grease into the oil which eventually disolves to cover up the racket caused by worn bearings. If it make a lot of noise with the recommended oil in it, the engine is most likely been abused like a rented mule.
I can't imagine that a bike would run well, without the carbs, that begs some serious questions.

[blowerbike]

folks these are roller bearing engines that could care less about the weight of oil.
these engines don't knock like a car.
i ran 20/50 in all my GS's through the summer months..
what was i hiding?
thats my point.

[GSXTommy]

I have run the bike without the air filter on my carbs without any problems but it`s not good to do so. but when you suddenly got ratling/cranking in your engine and your oil lamp start to light up, something tells me that your engine don`t get the oil pressure that it shall have. Poor oil pump or poor oiling in the engine and the parts. it can also be that some part have been seal`d up because of dirt in the oil or too thick oil. I also thinking about the oil pipe on top.

[MikeJ]

folks these are roller bearing engines that could care less about the weight of oil.

I'm not disagreeing - while that is true, OP said his engine sounded like it had "rocks in the HEAD." I don't think he was talking about the roller-bearing bottom end, sir. And the roller bearing crank won't have anything to do with how the top end components sound, or how worn out they are.

these engines don't knock like a car.

"Knock" is a whole different thing. Nobody was talking about "knock," pre-combustion due to excessively-low-octane gas or due to carbon deposits in the cylinder. We're talking about camshafts, cam chains, pistons and rings, etc. all rattling around because their tolerances have been loosened up due to excessive wear, perhaps due to some kind of abuse. Or, maybe not. But, such out-of-spec looseness, and resulting noise, can happen.

Frankly, I'm not so sure you're right about "these engines don't knock" either. Try running one on kerosene or diesel fuel or 70 octane gas and see if it "knocks."

i ran 20/50 in all my GS's through the summer months..
what was i hiding?

What were _you_ hiding? Nothing, sir, assuming your GS's are in good shape. Which we have no reason to doubt. But -

What was OP's PO hiding? We _don't_know_. But I offered, as a possibility, that _maybe_ he was hiding something wrong with his top end, masking the noise by using heavier-than-spec oil.

The fact that both you and OP's PO ran 20w-50 has nothing to do with the possibility that the PO of OP's bike was hiding something, even though _you_ plainly were not. The 2 of you ran heavy oil for different reasons, it seems.

thats my point.

But your point is based on assuming that I said _everyone_ who runs heavier-than-spec oil is hiding something. No one ever said that. What I did say, was that _some_ unscrupulous sellers of cars _or_ bikes, _do_ cover up problems with their engine internals by using super-heavy oil, or by larding the oil with heavyweight additives like STP, or by putting oatmeal or sawdust in the transmission (haven't heard reports of anyone doing that last trick since the 1950's, but I offer it just for an example)

Apples and oranges, sir.

[tkent02]

by larding the oil with heavyweight additives like STP, or by putting oatmeal or sawdust in the transmission (haven't heard reports of anyone doing that last trick since the 1950's, but I offer it just for an example)

Squished bananas will make a noisy differential run really quiet. For a while.
Probably even work on a GS shafty.

[blowerbike]

mikej you went to a lot of trouble for nothing typing all that stuff..IMO
the knocking i'm talking about is bearing shell knock...roller bearings do not do that.
also..
i see it as someone assuming the previous owner was hiding something..
aka the 20-50 oil.
when people call me and ask what weight of oil i ask there location and how they ride..ride hard/ride in traffic and so on.
i recommend 20-50.
i stand by my 20 plus years of working on 90% GS engines and i stand by my opinion(s) as well.
no plssing contest here...
someone mentioned "previous owner may be hiding something"
thats where my comments was pointed.

[bmac]

After reading the first post, I would get a manual. It was stated that you replaced the oil and added 3.6 qrts. If you did not change the filter you have to much oil in it. 3 qrts. is added without a filter. Do all the proper maint. items listed by the members and put the proper equipment on it and see where you are at and change that filter. I believe 10w 40 or 20w 50 oil are both fine, as long as the are made for air cooled, wet clutch applications ONLY. bmac