now can you take a look at my plugs?

[satchmo]

Ok. I better start from the beginning. Bought a 1984 GS1150EF from a dealer on a trade late last summer.

Now the one thing I noticed immediately was that it was getting really crappy mileage 15l/150kms or so.

It had a problem with the petcock, it was stuck in 'on' wouldn't go to reserve or prime, so I replaced it.

It's still sucking gas like a freight train. This weekend I spent some time getting some other stuff on it working right (reattached my speedo cable which came off at the end of the last season, adjusted my headlight, cleaned air filter)

I also pulled my plugs to get a read, and I was going to run a compression test (but my gauge wasn't the right thread size -- need to get an adapter), to see if a valve job needs doing.

Anyways, here are the plug results -- they're all pretty uniform in looking like this

Here are some blurrier shots (apologies)

Now I'm reading this as they're running too rich. I was planning on pulling the carbs next weekend and replacing all the o-rings (thanks Robert Barr, they came super quick), and then finding a way to sync them, but I just want to check with you guys as I'm still a neophyte in the wrenching area.

How can one tell if the valves need doing?

I also need to replace my chain, and get new tires, in advance of the trek to W. Virginia in August. Fun stuff.

 

[deves3000gt]

plugs look rich. how is the idle? check to make sure the air mixture screws are right.

 

[satchmo]

plugs look rich. how is the idle? check to make sure the air mixture screws are right.

Idles right around 900rpm no problem, no sputtering, no hickups, pretty smooth actually.

It gets a little sputtery around the 4000rpm range, but doesn't lose any power.

Thanks for the reply.

 

[Boondocks]

The plugs show the fuel mixture to be waaaay too rich if the recommended spark plugs were installed. No wonder you're wasting gas.

With the correct fuel/air ratio, the plugs should have a light brown color.

 

[mark]

Way too rich as others have said. They're all the same though. Could be mixture screws maladjusted, or too much jet or needle. Could be a blocked air filter.

Do the throttle chop test. Test at 1/8, 1/3, and full throttle (if possible) (run at steady throttle setting for a minute or two, hit the kill switch and check the plugs) to see if its rich at all throttle settings..........that would help a lot it seems.

When mine was doing that it WAS the air screws.

 

[bwringer]

The only way to see if the valves need to be adjusted is to check them at the recommended mileage intervals. They do not generally make noise when they need to be adjusted -- GS valve clearances tend to decrease, not increase.

 

[earlfor]

Well Alex, I assume you havent had a chance to really go through the bike since you've had it. The condition of the plugs could be a lot of small things combined or one major fault. Usually its a cumulative result from a lot of little things that arent quite right. All four plugs look about the same. Thats a good thing and indicates a uniform problem, so the cause is probably constant for all four cylinders. I would rule out valve clearances as being the problem at this stage, because if valves are out, the cylinders will not run the same. (probably would not hurt to check clearances, but I dont think that is the cause) Likewise for compression. Again, it wouldnt hurt to check compression so you know, but my impression is its pretty even across the board. I will guess compression is even. It may be down a bit, but less compression is less induction and I dont think it indicative of your condition. Common to all four cylinders is electrical and carbs. I WOULD check voltage to the coil supply wire (12v+ orange/white wire normally) With the ignition on, you should see about the same as battery voltage with the coils unplugged and just reading voltage on the supply leads. Low voltage to the ignition system will give a weak spark and dark plug readings. It would also explain the roughness when the engine reaches 4k rpm or so. After that, common to all four, most suspect would be the "O" rings on the fuel inlet valves in the floatbowls. If they are not shutting off fuel when the float is at the full mark and overfilling the bowls, you're going to be running rich and using excess fuel. Also, a carb synch is essential. I suspect that is part of your problem too. Also, take your multimeter, set it to the ohms scale and measure between the terminals on each coil with the coil unplugged/not powered up. You should have between 3 and 5 ohms between the terminals. Then set your multimeter to the 50k (50,000) ohm scale and measure resistance between the contacts in the plug caps, 1,4, and then 2,3. You should show between 30,000 and 50,000 ohms.

While you have the carbs out and are replacing "O" rings, you might want to check to see what main jet sizes are installed. Stock for the 1150 is a #120 for the 1 and 4 cylinder and a 122.5 for the 2 and 3 cylinder. You can set vacuum synch the same across the board. There is no need to set different values for 2,3 as clymer and others call for.

Also, check your airfilter. A clogged filter will cause dirty plugs. Unless the filter is really packed up badly, I doubt it would cause plug readings that dark though.

If you have the stock electronic ignition, it is non adjustable, so there is nothing to do there. Either it works or it doesnt. If you have an aftermarket electronic ignition, the best bet is if you have, or can borrow an inductive timing light (one that simply clamps the pickup on the #1 spark plug wire, it is very easy to do a running visual check of the ignition timing.
That the bike runs OK and you notice no stumbling or anything suggests to me the timing is ok as is, but you never know for sure until you have a lookie see.

Earl

 

[satchmo]

Thanks guys.

I'm going to check the electronics later this week and pull the carbs on Friday.

Glad to hear that it's probably not valves.

There's a K&N air filter in the air box, which I'm assuming isn't stock, I cleaned it and oiled it today but no difference in how she runs. I'm wondering if the PO put in bigger jets when he changed the air filter.

Bastard.

I'll post my results back in this thread later.

Thanks again.

 

[satchmo]

Continuing with this thread ---

one silly little question -- what colours were the carbs on an 84 1150. Mine are black, but I'm wondering if they've been painted, as a pair of vice grips has had much more luck removing screws then a screwdriver does.

 

[satchmo]

Alright. ANyone no the part number for a float bowl gasket for an 84 GS1150Ef -- everything I've said says 13251- 44080-H17

I ordered 4 of these from the dealer, and while close, they are not perfect -- they have an extra "bump" with a hole in it on the opposite side of the needle seat.

I'm also wondering why anyone would change a pilot jet -- my manual calls for a #45 pilot jet, but in carb #1 -- the only one I've taken apart so far, there's a #47.5 in it.

Also my mixture screw (labelled the air screw in the carb cleanup series) doesn't have a washer or an o-ring -- is this going to be a problem? Should I add an o-ring?


I can feel my self starting to get frustrated. I want to have this thing up and running like a top before W. Virginia so it doesn't cost me $400 to get there and back.

 

[robertbarr]

I'm also wondering why anyone would change a pilot jet -- my manual calls for a #45 pilot jet, but in carb #1 -- the only one I've taken apart so far, there's a #47.5 in it.

Also my mixture screw (labelled the air screw in the carb cleanup series) doesn't have a washer or an o-ring -- is this going to be a problem? Should I add an o-ring?

On bikes as old as we work on, there's no telling why something was done (unless you have the luxury of knowing everyone in the ownership line).

One possibility -- and what I'd guess is the most likely -- is that some PO bought a rebuild kit (s) and the kit came with the 47.5. Presuming that new is better than old & used, they installed the new jet.

What happened to the washer & O-ring is another question with no answer; you now have the O-ring, but finding a tiny shim to fit that screw could take some patience. I've never tried the Radio Shack trick with those -- might be worth a try, but you definitely want them in place.

I have never measured those washers. Perhaps I should, someday, and start hunting for a source, since I get a lot of questions about them.

 

[satchmo]

Thanks for the reply Rob.

I've taken apart carb two and found the same thing Pilot jet 47.5 mixture screw with no o-ring or washer.

All the mixture screws were way out too -- set about 3 turns out from seated, whereas the manual calls for 2.

Also the PO F***D up the seat assembly by screwing the phillips in way too tight, so I can't get them out with out stripping them, and my vice grips are too big to get in there. I'm going to have to search for an impact driver, or a smaller pair of vice grips.

Unfortunately I've got to put the bike back together until I can get these parts, as it's my only form of transportation.

This bites.

I just hope that I can get this mileage stuff figured out before W. Virginia.