Neophyte motorcyclist with an engine problem

[Lucien Harpress]

How's it going?

My story is the same as many others on this site (I know- I searched)- first-time bike owner, bought it from some guy who had it sitting in a barn for at least a couple of years, sadly with gas still in it. It ran (albiet sluggishly), but trying to get it to do something other than idle has been an... adventure? A pain? Pick your adjective.

The bike in question is a 1980 XS1100 Standard. Long story short, I can get it started, and I can get it idling. However, it only idles at half-choke, any less and it dies. In addition, even after warming up for 20-25 minutes, you can't even THINK about touching the throttle at all, unless you want the engine to die, of course.

When it IS running, there's quite a bit of popping/backfiring, coming from cylinders 3 + 4 (the two on the right side, when viewed from the back). I'm not sure if this is an issue connected with the larger problem, or a side effect of running on half-choke.

Now, I've seen countless other threads about similar problems, all with the same answer- "Crack open the carbs and clean them." I guess I'm trying to avoid this at all possible. I'm not what you'd call mechanically inclined- when I look at an engine, I'm not sure what half the stuff does (even AFTER reading the various FAQs on the subject on this site).

I guess what worries me most is the fine-tuning/syncing when you put them back in. No clue how to do this, what to look out for, WHY to do it, and how not to screw it up.

So, what do you think? Is this a problem that can be corrected without resorting to tearing apart a precision-mechanical instrument, or am I going to have to bite the bullet? (If so, be prepared for deluge of further questions!)

Thanks in advance.

(I DO have a camera, and know how to use THAT, so if anyone needs further photos/information, PLEASE let me know.)

[tarzan]

"Crack open the carbs and clean them."

Sorry,I couldnt resist.
I would highly recomend you clear off a good spot on your workbench,kitchen counter ,or someplace you can disassemble and thoroughly clean each carb.One at a time,so you dont mix parts between carbs and you will have a reference in case you forget where something goes.
If you take your time and take some pics and if you have problems or just questions just ask and post pics so we know what you have you will get through it.
Welcome to XS11.Hope you get it running right.
Rick

[trbig]

Put your camera to use and take the carbs out. Take pics step by step so you remember where stuff goes. Any parts you aren't sure of on re-assembly.. take a pic and many people here can tell you where it goes.

Once you remove the carbs, turn them upside down. They'll have a considerable amount of fuel still in them.. but I would dump it anyway. Probably has trash in it. With the carbs upside down, you're looking at the bowls. There's a screw on each corner.. do the carbs one at a time. Remove the 4 screws holding the bowl and lift it off. At this point, I wouldn't even worry about removing jets or anything.. no messing with any settings. Get a couple cans of GOOD carb spray. B-12 works much better than store brand generic. Put the plastic straw on and spray through the two jets there. There's one under the floats, but I wouldn't mess with that unless fuel flows out of the carbs when the motor is off. Next.. on the intake bell of the carbs, you'll see some air jets. Spray though those also.

Spray everything down well, then pick up the bowl. There will be sediment and crud in the bottom, but on the actual edge of the float bowl, there is a hole. The long brass tube on your carb goes into this hole and at the bottom of it (The hole) there is a small brass jet. Spray down this hole through that jet until it shoots out into the bowl nicely. Next, stick the plastic straw into where it was coming out.. and force some carb cleaner through that jet that way.. but be careful. This one has a tendency to shoot you right in the eye.. and B-12 is a lot like pepper spray when this happens.

Pretty simple. Put the bowl back on.. most of the time you can re-use the gasket if you're careful when you remove the bowl... put the 4 screws back in and go to the next one.

These carbs really are simple.. even for a guy like me that thinks they are still magic a bit. (That electrical crap is pure David Copperfield in my eyes!) There's nothing in there spring loaded that's going to go shooting out.

There's certainly more you can do to them.. but if the bike was running, you may be close with it the way it was. If not.. they really aren't that hard to get out, and you'll get a bit quicker each time. If you get it running, I'm betting there would be somebody who could meet up with you and hold your neophyte hand and walk you gingerly through a carb adjustment and synch. This usually involves payment with a meal and beverage though..

Tod

[rlundy]

A well written ode to "I don't want to take the carbs apart". I'm in a very similar boat.

I did something similar in the buying (except mine was dead, no power anywhere until this site told me where to look for the burned connector in the headlight bucket), but I do have experience cleaning and poking around in outboard motor carbs. These carbs are more sophisticated than outboards. You will eventually have to buy a sync tool, like I did.

So, the second day I had the thing, after I was able to figure out my power problem, i gave it the "h@lf @ssed" carb cleaning. Which, if your is idling a bit, mayy work at least so you can get a ride in.

On the bottom of each carb there is a drain. Easy to remove. Make sure the petcocks are in the run position (not prime), remove these and let the carbs drain. If you have strong character, leave the bike alone for a couple of hours after this-the carbs dry out. Put a towel under the carbs to catch all the gas.

Get a large can of aerosol carb cleaner at your nearest autoparts store. Insert the straw on the nozzle and put the straw into the first carb while putting your finger over the hole. If you've pulled the air filter bottom housing off, spray until the bowl is full and its running out the throat of the carb. It'll take several seconds. keep your finger over the hole. This is important.

Now, while the carb is full of cleaner, turn the bike on and turn it over a few revs (it helps to have a friend over-give him a beer for his other hand). This will suck the cleaner into the low speed jet and, hopefully, clean out the gunk. The high speed jet might even get clean, just because its orifice is larger (and its not a prone to clogging).

Do this process for each carb. Put the drains back in, set the petcocks to prime, and see how it runs at that point. I'll bet you can hop on and ride it around the block.

I did this procedure three times in three weekends-until I realized that my tank was lightly rusted and the tiny rust particles were clogging my low speed jets every time I rode the bike. At the same time, I proved it ran, I liked it, and it made it worth all the other work it needed (the riding was done with the front brakes removed-they were stuck, using only the slightly sticking rear brake).

While you're at the auto parts store, get a can of seafoam and dump in 1 can to about 2 gallons of gas. Ride it a bit each day for a week. If the carbs are just a bit dirty, this will clean them even more, plus it cleans some carbon out of the motor. It will also loosen the rust and varnish in the tank, which may mess the carbs up more eventually (but at least your tank will be cleaner!)

Don't be scared if you crank it the second day after with seafoam has been sitting in the carbs and it smokes out the nieghborhood-this is the carbon burning off the top end (pistons, rings valves) and is a good thing.

I've had to pull my tank and do a POR-15 coating. The rust wasn't bad, but it was so fine it kept gumming up the carbs. And now its done, so I don't have to think about it anymore. You'll eventually have to pull the carbs and clean them throughly. But it makes a big difference if you can get a feel for the bike by riding it. You have plenty of fun with electrics and brakes before too long anyway, and the 40 miles I rode here and there makes me know its all worthwhile. And everything you'll ever have to do has already been done by experts on this site.

Welcome.

[mstic2000]

Also, another thought. You can find plenty of videos about how to clean carbs on www.youtube.com. Just do a seach for "motorcycle carb cleaning." You tube has got some pretty good videos about this subject and the do's and don'ts.

[CatatonicBug]

Yeah, you're actually not in too bad of shape if it actually STARTS at this point. I'm assuming you drained all the old fuel, and replaced it with new? You definitely need to remove the carbs and open them up. It's really not as hard as it sounds. Take it step-by-step and be aware of each piece you take out. Try to think about each thing and learn what it does. You will be suprised how much more confident you'll feel once you have it all back together and running again! There are plenty of folks here who have been in exactly the same position you are right now, and can now give expert advice without even having to think about it.

Pay special attention the to little tubes in the BOTTOM of the bowls attached to the bottom of the carbs. I had a similar issue with mine in the beginning. I could run it fine as long as the choke was pulled. After I cleaned out the jets in the float bowls, it runs great.

[Lucien Harpress]

Yes, the fuel is drained and new put in. I did run it a bit with the old gas in it, though, just to be sure it ran. I hope I didn't mess something up doing THAT....

Thanks for the tips, everyone. It's not so much the taking apart that has me worried, it's the putting back together and actually working.

I can try the "half-a%^ed" carb cleaning to start. If I don't have to mess with the floats, the jets, needles, ANY of that right now, I'd be really happy. If I do? Well...... let's just get an initial cleaning done first, right?

I'm not doing anything tomorrow. I'll see if I can at least get the carbs off the bike to start with. Gotta start somewhere, right?

[Ken Talbot]

If I don't have to mess with the floats, the jets, needles, ANY of that right now, I'd be really happy.

Yup, and that would be some kind of miracle! Go ahead and do it that way for your first time, and it will help you build a bit of confidence for your second time in. Rest assured there will be a second time. And, depending on how much farther you go with the second time in, it will run better than before, and you'll have even more confidence for the third time in. Have patience, keep track of what you're doing, and show no fear. There's lots of us here to backstop you and help you through it.

[DGXSER]

Yep, Gotta start somewhere and then take another step and then another and then you look back and you crossed that big scary bridge!! Read the tech tip on how to remove and clean, it is VERY good and fairly detailed on how to get them out.

One added word of advice on the carbs, if you get brave enough to pull the jets out, first soak them with some kind of penetrating oil like PB Blaster for a few hours or so. Will do wonders for getting them out based on my experience. And no, WD40 is NOT the same thing, again from my experience. WD40 will however do wonders for getting them back into the boots on re-assembly!

There are ALOT of VERY knowledgable folks here so as Ken said, go for it, they/we got your back. (I know about a third at best of what some of these folks know). Also, use that camera and ask questions BEFORE doing something your not sure of. Never seen any body go wrong following the advice they get on here, but seen a few have issues from not asking first. No such thing as a dumb question.

[fredintoon]

Hi Mike,
the smaller the hole, the easier it gets blocked. The smallest holes are in the idle and enrichener systems.
The previous posts all gave good advice but I don't see two really basic things:-
1) Do all the carb work in a big metal tray to lessen the chance of losing small parts.
2) When you take the jets out (not "if"; "when") Buy some cheap screwdrivers and re-grind the tips to be an exact fit in the jets to lessen the chance of wrecking their screwdiver slots.

[DGXSER]

Buy some cheap screwdrivers and re-grind the tips to be an exact fit in the jets to lessen the chance of wrecking their screwdiver slots.

Agree completely, this is CRITICAL for the small pilot jets and the mixture screws for sure!! Won't hurt on the main jets and pilot air jets either. One "adjusted" screw driver will work for more than one jet though.

[Lucien Harpress]

Well, step 1 is finished- ie, getting the carbs out of the bike. Not too bad. I had enough time to get one of the carb bowls (No. 4) off the bottom of that carb. Sure enough, there was a bit of crud in the bottom of the bowl. Does that translate to crap elsewhere? Probably.

I'm going to wait to do anything else until I get some better carb cleaner. Then I look back through the posts here to see what and where to spray. In the meantime, I can get some photos up probably tomorrow night.

[CatatonicBug]

Yeah that gunk is what stops up all the teeny tiny holes in the jets and ports in the carbs. Just have a few (at least 2-3) cans of spray carb cleaner on hand, and use the little straw thing on the sprayer to get down in the little holes. Remove all the jets, and clean them really well. You can replace them if they are really bad (carb kits with jets are about $25/carb), but that's not always necessary. Use a tiny wire (one strand of wire from a stranded electrical wire) to clean the jet in the bottom of the float bowl. Then, use compressed air to blow all the left-over junk and cleaner out of the carb. Take your time, and don't get too frustrated. Do them one carb at a time or lay out the parts in groups, so all the parts go back into the same carb they came out of. As was mentioned earlier, when you're all done, a quick shot of WD40 on the inside of the rubber carb holders will really help to slide the carbs back in.

[Lucien Harpress]

Fuel flow issue- I think.

Okay, a bit of an update.

I managed to get the carbs open, and they didn't look too bad. I got carb cleaner into the spaces I could, then shut everything up and put it back into the bike. I got it running- for a few seconds. Then back to the same old symptoms.

I DIDN'T want to tear the carbs out again straight away, so I tried to think what else I could do. My dad mentioned something about not getting adequate fuel flow. While the carbs were disconnected, I checked the petcocks and both worked fine. (Got a mouthful of gasoline, too, but that's not important to the story)

Out of curiosity, I switched both petcocks to "Prime" (ensuring fuel flow) and tried firing the engine up. Surprisingly, it worked! Idled without choke, throttled (relatively) smoothly, lack of any major backfiring (that I could tell). The only issue was that when I goosed the throttle and the motor ran back down, then it stalled.

I know this isn't a fix, but at least it's a step in the right direction.

Do I have some kind of vacuum leak somewhere, bad petcocks, or what? Any other clues on what to check?

[TopCatGr58]

Hey there Lucian,

Okay, found the beginning of the thread that it's an 80 Standard, would be good for later threads/discussion to EDIT your Signature to show your year/model.

Okay, you said you got a mouthful of gas? It might actually be important as to how?? Did you try sucking on the vacuum hose that goes from one of the carb intake port to the petcock? If so, then the petcock diaphragm may be damaged allowing fuel to leak into the vacuum hose?

Or, you could have a crack in the vacuum hoses, and so that they are not providing the proper vacuum to pull it open to flow during the run mode. The prime mode allowed them to flow without the need of engine vacuum.

You may want to take the petcocks off and take them apart to inspect the parts. But hopefully it's just the vac hoses that are messed up??
T.C.