87 vulcan starter spins but doesn't start

[Alans87]

Hi all, new to the forums and looking to see if i can get some help. I just recently purchased a 1987 vulcan 88 1500 from a tow auction yard so I don't have any history on this bike. It supposedly ran, so i started doing some simple stuff to see if i could get it running but quickly started having problems.

So heres the timeline of what I've done:

-Drained the old fuel, replaced with new.
-Checked oil level window.
-Checked for spark, got white sparks showing
-Sprayed some starting fluid and got it to kick over for just a bit but died, engine sounded pretty rough.
-The engine would no longer turn over. This is where the I thought i had seized the engine, I was using a fresh car battery so I know i had plenty of juice but the starter was clicking instead of turning over.
-I looked at the oil window, then cross referenced a diagram I found on the bike and realized to my dismay that I had been looking at the radiator overflow tank instead of the oil window.
-I got pretty desperate at this point, immediately opening up the oil fill port and putting in half quart of 20w-50 4 stroke oil and 2 quarts synthetic car oil 20w-50. after this i finally found the oil level window located way down on the bike between the frame and exaust (which was now showing overfull).
-After some time the engine finally slowly turned over by just using the starter.
-Drained out the oil, got 3.5 quarts out meaning there was 1 quart of old stuff in the engine to begin with (there was gray stuff swimming in the oil, making scenic shapes, whats this stuff?).
-Put in more 20w50 car oil and added new plugs.
-Engine spins nicely now (hoping its not too messed up now), but doesn't start even when using starting fluid.
-rechecked gas flow, which is ok coming to the fuel filter and going out of the fuel filter (and can smell it in the exhaust but haven't checked anything with the carbs).
-rechecked for spark, noticed the spark was angling from center electrode to the vertical part of the upper electrode so I shortened up the gap to .19mm and spark was jumping straight across now.
-Engine still just spins, no coughing or semi detonation or any sign that there is spark lighting the fuel in the pistons.

Now I'm stuck, could it be the spark isn't strong enough and needs new coils? Its 98 dollars from the kawi dealer guh! Could the timing be off? (note that the bike did start up once shortly, so i figure the timing should at least be in the ball park). Could the bike not be getting enough air? i notice that the air is coming out of the intake pretty strong which seems backwards since i expected it to be sucking it in, not blowing it out.

Thanks for any help.

Alan

[StarGate]

First of all you said you got "white" spark. Thats bad. You should have a strong blue spark at the plugs. If the battery is strong then it's probably low voltage to the coils. The grey stuff in the oil hmm, you know what the white stuff is in chicken $hit? More chicken $hit, same thing with the oil but you could have some condensation mixed with old oil. You should really replace all fluids, filters in the bike before trying to run it. That includes brake fluid, antifreeze etc. Buy some new plugs and gap them correctly and install them. If you still don't have a strong blue spark then start checking for low coil input voltage, bad plug wires/caps. You might get lucky and it starts up and runs decent but I'd put my money on a good carb cleaning being necessary.

[Bill Frazier]

-rechecked for spark, noticed the spark was angling from center electrode to the vertical part of the upper electrode so I shortened up the gap to .19mm and spark was jumping straight across now.

I'm not sure what the exact gap spec is for this model. but .19mm is WAY too small. It should be maybe four times as big, say .7 or .8mm.

[Alans87]

Originally Posted by StarGate

First of all you said you got "white" spark. Thats bad. You should have a strong blue spark at the plugs. If the battery is strong then it's probably low voltage to the coils. The grey stuff in the oil hmm, you know what the white stuff in in chicken $hit? More chicken $hit, same thing with the oil but you could have some condensation mixed with old oil. You should really replace all fluids, filters in the bike before trying to run it. That includes brake fluid, antifreeze etc. Buy some new plugs and gap them correctly and install them. If you still don't have a strong blue spark then start checking for low coil input voltage, bad plug wires/caps. You might get lucky and it starts up and runs decent but I'd put my money on a good carb cleaning being necessary.

I'll replace the coils then, maybe i can find a place that sells them cheaper than the $98 that the kawasaki dealer wanted, and i need 2 of them to feed 4 plugs. If the wires were bad i wouldn't think I would get a spark, but maybe they're bad enough to eat up some of that spark. Funny how I've never seen white spark before now, this is one of my first tries at working on a bike (and I'm sure it shows brightly).

Thanks stargate for the response, I'll post again once i can get past this part and hopefully get this beast running.

Alan

[Alans87]

Originally Posted by Bill Frazier

-rechecked for spark, noticed the spark was angling from center electrode to the vertical part of the upper electrode so I shortened up the gap to .19mm and spark was jumping straight across now.

I'm not sure what the exact gap spec is for this model. but .19mm is WAY too small. It should be maybe four times as big, say .7 or .8mm.

The plugs I pulled out were probably that size, the info decal on the bike says to run .32 (or is it .032) inches and thats bigger than what I gapped them at. This is probably due to what stargate pointed out, not enough voltage to jump the normal gap properly. just need to locate some cheap coils now

[Bill Frazier]

8mm is about .032", and is a good ballpark figure for most plugs.

[StarGate]

I wouldn't rush out and buy new coils. It's much more likely to be low voltage to the coils than to have a bad coil. If you end up needing another coil, I still have the ones I pulled off mine when I upgraded to dyna coils. They were both working fine although one had a visible crack in the outer housing but if you really needed one I'd let you have them both for the cost of shipping. I'm serious about check the coil input voltage because it's a very common problem when you have weak spark. I'm not sure these coils are the same as your bike uses though.

[Alans87]

Originally Posted by StarGate

I I'm serious about check the coil input voltage because it's a very common problem when you have weak spark.

How do i check the voltage going into the coil? there are several non-plug wires connecting to the coils (2 per coil), then there are the plug wires connecting to the coils. If i'm checking the non-plug wires, would that signal be a DC pulse of 12v and 0v?

I was going to connect some coils i had lying around, but after pulling out the old ones i didn't think i would be able to just throw in the new ones without doing some modification. So i did the next best thing, cleaned off all the leads, reinstalled the old coils then kicked it over and saw I had blue spark this time instead of white. I've still yet to get the thing to idle, but it finally had a moment here and there where it was running without the starter (for just a second). It's still being real stubborn though and won't stay idled, but the more its turned over the more it seems to be working out whatever is holding it back. I'd still like to figure out how to check the input voltage, maybe if I can get more voltage in somehow that it would be just enough to get me to the next step in getting this bike going.

edit: Note that after reinstalling the old coils i then gapped the new plugs to 0.033in. The diagram inside one of the bike ferrings calls for .032-.036 gap, so this should be good now. It also mentioned something like 5 degrees retarding (which i have no idea how to adjust timing on this thing), but I'm just guessing on that figure because i don't have that ferring right in front of me, i'll get the exact figure and post it later.

[Bill Frazier]

With the ignition on, but the motor not running, touch the - lead of your meter to the bike frame and the + lead to each of the primary (non-plug) terminals. One should read 0 volts and the other around 12 volts. If it is much less, clean all terminals and try again. If it is still too low do the Wired George modification. (Use search function for details.)

[StarGate]

Yea, what Bill said. The voltage should be about the same as when you put one meter lead on each of the battery terminals (direct reading of the battery voltage). Preferably it will be less than 1 volt lower than the battery. If it is more than 1.5v lower than battery voltage then you need to do some work on it.

[Alans87]

Thanks for assisting me with this stuff, its much appreciated. I'm headed out now to check the voltages and see whats what, I'll post again shortly.

[Alans87]

With 13.5 volts at the battery, I confirmed 12.75 volts at the coils, so I wouldn't expect spark to be an issue at this point. I riggged up a cup of gas to the gas line into the fuel filter, it's not pulling any gas through. As far as I know the fuel is gravity fed not pumped, so i should have seen the gas level drop fairly quickly (used a small cup of gas). For the fuel filter, I was able to blow gas through yesterday, but I'm going to pick a new filter up today to be sure.

[Alans87]

I continued to troubleshoot the fuel lines. I was able to get gas to flow through the fuel filter no problem, no need to replace that until later. from the fuel filter it goes to a metal tube with an in/out ports and looks crazily like a fuel pump (though i've heard the fuel is gravity fed). So i pulled the line of the output, put gas in the line at the input, hooked the battery back up and hit the starter. Fuel was spitting out in pulses, I'm thinking this is either a fuel pump OR some kind of fuel stop to help meter the gas and keep it from flowing freely to the carbs at all times. So onto the next item in the fuel line, the carb. This is where I slow way down, I've got no expertise here. I once rebuilt a 2 barrel on a 78 monte carlo, but that was by no means simple for me or was I able to do a complete job on that. I'm probably just going to take the carb off and stare at it for a couple hours, maybe something will jump out at me lol (like a nasty green motorcycle carburetor gremlin). I shall perservere and emerge victorious or die of gas fumes trying!

[Alans87]

At this point I am trying to get anything to happen before removing the carbs. I've heard tapping the carbs can loosen stuff up, so i tried that and then watched the fuel level while turning it over, then repeated. I noticed if i waited about half a minute between turning it over that the fuel level would go down just a bit as i first turn it over but that would be it no matter how long i turned it over. Then i located what i think is the float bowl and backed out a screw, which let quite a bit of gas out. I did this for both carburetors then retightened the screws and turned the engine over again. This time the fuel level dropped rapidly, enough that i had to refill my cup before it stopped sucking it down. SO it seems that the fuel from is getting all they way to the float bowls but i'm not sure what happens after that.

[Alans87]

ugh, frustration. At this point i'm refraining from removing the carburetors because I can see and smell gas on the plugs, so i think i went on a wild goose chase there. I again looked at the spark (guh) to make sure I had good spark and well, its kinda blue, kinda white, i can't really tell which probably means its not good spark. And with gas in the chambers, and I'm pretty sure air is getting in there too, it must be the spark that's either not hitting at the right time or not enough to make a difference.

[StarGate]

Along with that fuel/air, spark, all at the right time you also need compression. Have you done or are you planning on doing a compression check?

[Alans87]

Originally Posted by StarGate

Along with that fuel/air, spark, all at the right time you also need compression. Have you done or are you planning on doing a compression check?

Tried a compression test but the tool i used has to be pressed into the plug hole which wasn't quite big enough so i couldn't create a seal while turning it over. I decided to go ahead and remove the carbs, pulled the dual set off and opened up both bowl chambers and removed the jets, soaking them in gas and cleaning out the middle. 1 of the jets was clogged, i don't think it was the main jet but the other one that the hole runs all the way through. The vacuum valves for both carbs were in good order, no rips or tears. 1 of them had a slight bunch-up where the cap had pinched it, i'm assuming the diaphram wasn't in the groove proplerly when it was last installed. After that I had to reassemble the carbs before leaving for the work week, i didn't want to leave them in pieces and forget how they went back together. I'm thinking of taking them completely apart again and soaking them after removing the o-rings etc so be sure everything is cleaned. That or just doublecheck the floatbowl heights and throw them back in and run seafoam, i'm hearing from these forums that its good stuff.
Can't wait till my weekend starts!

[MFolks]

Be very careful in not getting carb cleaner on those rubber diaphrams as it will eat holes in them destroying the function. In fact any rubber items like O rings are in the same catagory.

Here's something I got on the internet about carb cleaning:

Carb Cleaning 101

By M. Shively

The elements of internal combustion engines are: correct fuel/air ratio, spark at right time, adequate cylinder compression.

There are many passageways and openings to check and clean. All are important in function and when obstructed or not working properly, have subtle to radical effects on engine performance. Vacuum leaks and carburetor synchronization also effect performance and should be inspected and adjusted following the below procedures.

Warning: Remove all rubber parts before you begin. These parts usually include vacuum diaphragms, needle valves, o'rings, hoses, and other parts. Spray cleaners will damage these parts. Do not disassemble individual carbs from the carb bracket.

Air & Fuel Passageways: Trace and learn individual fuel and air circuits from beginning to end. Machines can only drill straight through the cast passageways. To change direction, another angled passageway must be drilled. The union is plugged with a brass or bronze bead. Inspect and clean each passageway with spray cleaner, brushes/pipe cleaners/etc, and compressed air. Remove any discoloration and debris. Look for spray cleaner to exit from one or more passageways.

Jet Cleaning: Inspect jets by holding to light and look through them. You should see an unobstructed round hole. Clean the jets with one or more of the following: jet cleaning wires, soak solutions, carb spray cleaners and compressed air. Re-inspect jets after cleaning and install when clear of obstructions. Some main jets have paper-like gaskets. Most have metal spacers between the jet and the emulsion tube. Some screw directly into a brass emulsion tube which is machined for a 7mm wrench at its float chamber exposed base.

Inlet Fuel Valve: Inspect the needle valve & spring. Press down the tiny metal rod that protrudes from the butt or float end of the needle valve. The spring should move freely and return the rod to its location. Check the needle valve's seat area for a groove or other wear. It should appear highly polished. Some needle valve seats are rubber and wear may not be visible. Inspect the needle valve jet seat. You can clean the jet seat with Q-tips and semi-chrome polish if necessary.

Carb Body Castings: Blow air through the atmospheric vent holes located on the dome of each float bowl chamber. Air should exit via hoses or brass nipples. Inspect the emulsion tubes and passageways (cast towers that jets thread into) for discoloration and debris. Clean interior emulsion towers with a soft bristle gun cleaning brush. Clean each Venturi (main carb bore).

Needle Jets & Jet Needles: Clean the needle jets, jet needles, and passageway or tower that needle jet screws into. Clean the emulsion tube (pipe between needle jet and main jet) (Main Jet may screw into emulsion tube). Jet needles are part of the throttle slides. See below…

Throttle Slides: There are several types of throttle slides: Mechanical linkage, vacuum, diaphragm, and cable. Disassembling the jet needle from the slide is not always required for cleaning. If you have vacuum piston type throttle slides (large diameter solid metal slide), avoid cleaning the lubrication from sides and caps. If piston type check cap vents and passageways with air. Clean if necessary and re-lube. If you have rubber vacuum throttle diaphragms, inspect for dry-rot, defects, and tears by gently stretching rubber away from center. Do this until all areas around diaphragm have been inspected. Replace any defective part as described above. Clean carb body areas around diaphragm including air passageways and air jets. Diaphragms have a locator loop or tab fabricated into their sealing edge. Observe this locator upon reassembly. Avoid pinching the diaphragm when reinstalling caps.

Fuel Screws: Fuel screws have sharp tapered ends. Carefully turn one fuel screw in while counting the turns until it seats lightly. Warning: These screws are very easily damaged if over tightened into their seats. Record amount of "turns-in" and remove the fuel screw, spring, washer, and o'ring. The fuel screw is part of the enrichment (choke) circuit...clean passageways as described above. When carbs are assembled, spray low PSI compressed air into diaphragm air vents located at intake side of carbs. Throttle slides should rise, then fall when air is removed. Lightly lube external moving linkages. Reinstall carbs and follow through with carburetor synchronization.

Throttle Cables: Lubricate cables periodically. If cables are disconnected from carbs or removed for replacement, etc . . . remember cable routing and ensure proper reinstallation routing. Avoid bread-tying, sharp bends, and pinching cables. Adjust cables so throttle grip has about 5mm of play or throttle slides or butterfly valves may not open completely (full throttle)(wide full open).

Float Bowls: Inspect float bowls for sediment, gum or varnish, crystallization, and defects. Clean all pipes, tubes, passageways, and embedded jets with cleaners and compressed air. Remove and clean the drain screw and area. Inspect bowl gasket and replace if necessary. Clean and inspect overflow pipes and tubes, look for vertical cracks.

Floats: There are several types of float materials: plastic, brass, black composite, tin, and others. Handle floats carefully. Avoid bending, twisting, denting, or other means of mishandling. Most floats are adjustable by bending a small metal tab near the float axle end. Do not change the float adjuster tab unless tuning fuel service levels. Clean metal floats by soaking or by spraying cleaner and wiping clean. Other material type floats may require replacement if cleaning is necessary. Inspect the needle valve (float valve) and seat. Check needle valve's spring loaded pin. It should depress and return smoothly and without resistance. Check the needle valve's tip for a worn groove. Replace needle valve and seat if either symptom exists. These parts wear together and must be replaced as a set.

Synchronization: This is a fine adjustment performed usually and preferably with the carbs installed and the engine running. The unusual part is performed with gauged wire with the carbs on the work bench. Carburetor synchronizing balances Venturi vacuum at the exhaust side of each carburetor, resulting with smooth idling and optimized performance at all throttle openings. Synchronization is checked using a set of gauges which are either air vacuum type or liquid mercury type. The gauges are connected to vacuum ports on the intake manifolds via nipple tubes or if sealed with screws, sync gauge adapters will be needed. With the engine running at temperature, and with a fan or means of forced convection aimed onto the engine, the carbs fuel screws and idle are adjusted, then the synchronization is adjusted via adjustment screws on the carbs. A reserve fuel tank is recommended for convenience of accessing carbs during this procedure. See gauge instructions and repair manuals for detailed use of synchronization gauges.

Notes: While carbs are apart, record the jet sizes. Look for a very small number imprinted on the body of the jets. Verify that numbers are the same for all jets on models with in-line cylinders. A few transverse-4 models and V-engines, the inner and outer carbs use some different size jets and it's important to not mix them up. If you have dial or veneer calipers, measure and record float heights. Perform measurements with floats just touching needle valves, though not depressing the needle valve rods. Replace fuel and vacuum hoses. Be sure to use fuel rated hose for fuel. Install or replace in-line fuel filters. It's a good time to remove and clean interior petcock fuel filters. Inspect carb manifolds for dry-rotting, inspect all clamps and air ducts. Inspect, clean, lube, and/or replace air filter(s).

[Alans87]

Well i went through the carb, found a stuck float bowl and clogged jets. Put everything back together and slowly got the carb back into place, 2 things happened:


First thing...IT STARTS!

Second thing...IT KNOCKS!

I'm gonna guess and say its one knock per 4 revolutions, it definitely follows the engine speed and its definitely coming from the engine. I only had it idling for just a minute to make sure of what i was hearing, i kept it as low rpms as possible while doing this. The higher the rpms, the louder/harder the knock becomes. I'm hoping its something i can fix without pulling the engine, any ideas?

Thanks for all the inputs so far,

Alan