Numnber 1 Cylinder Not Working

[fatbiker]

My 86 Max with 73K miles has been giving me trouble lately. First I pinched a wire that destroyed my fan switch and also burnt to crisp a ground wire. Got all that sorted out but now my engine runs poorly at all RPM's. I contacted Sean Morley and he sent an electrical test kit along with a new fan switch for me. Thanks Sean!! Here's what I've done so far.

With the motor running I pulled the ignition wires one by one till I found out that the number 1 cylinder isn't working. These are the things I've tested:

1. Pulled spark plug and tested for spark - good, fat, blue spark
2. Changed spark plug wire with a known good one - good, fat, blue spark
a. Cylinder 1 spark plug end was black but not wet or oily
b. Other three plugs were light brown, not wet or oily

3. Changed ignition coil for a know good one - still a good spark

4. Left spark plug out and did the sniffer test - I can smell fuel

5. Did a compression test on all cylinders:
a. Cylinder 1 - 185
b. Cylinder 2 - 180
c. Cylinder 3 - 180
d. Cylinder 4 - 180

6. Pickup coil resistance test - all coils tested around 119 with engine cold
and outside temperature of 91 degrees F. After warming up the engine
they tested at 135 +/- 5 . Outside temperature was 93 degrees F.

7. Charging system test - have bypassed the crimp, done R/R mod
a. Idle - 12.53v
b. 2500 RPM - 13.85

8. Carb sync - all carbs are synced

9. Replaced carb sync line plug with a known good one

10. Pulled airbox to look for obstructions - no obstructions found, slides move easily inside the carbs.

11. Did the Shotgun on carb number 1. When I pulled out the idle mixture screw it was missing the rubber o-ring. I did not see it stuck in there either.

12. With the airbox off and the engine running I sprayed carb cleaner into each carb.
a. When sprayed into cylinder 1 there was no reaction. Engine did not race nor did it die.
b. When sprayed into the other cylinders the engine died or came close to dying.

12. Replaced the CDI unit with a known good one. No change.

My guess is that the number 1 carb is clogged somehow. If I turn on the choke the engine won't start. When the engine is running and warm it will sputter and die with the slightest amount of choke. I don’t know if this is normal or not. Temps have been in the 90’s in the mornings around here.

Or, the pickup coils are bad and just aren’t showing it. I have yet to replace them with the ones Sean sent as I’d like your opiniosn first before doing so.

Thanks for all your help!

Fatbiker

 

[sdt354]

Are all snyc ports capped, and #2 port connected to the MAP sensor? Send a blast of air down the pilot jet and see if the o-ring comes flying out of the A/F adjustment hole. Sometimes the straw from a carb cleaner can can fish it out too.
Drain the suspect carb into a clear jar , cycle the key to keep adding gas. Any junk coming out with the gas?

http://www.vmaxforum.net/search.php?searchid=1206385

 

[adambweird]

Could have a cracked coil for the num 1 cylinder...

 

[fatbiker]

Already replaced the coil with a known good one and it did not fix the problem.
Also, already tried blowing out the missing fuel mixture o-ring with a can of carb cleaner. It's not in there; it's missing.

This afternoon I replaced the pickup coils with some that Sean Morley sent. The bike still won't work with the choke on and now there is a loud pop coming from the left muffler. It popped a few times then the bike died. I have not tried starting it since for fear that I've screwed something up.

 

[Redbone]

More than likely you have your front coil wire crossed. Be worth a check anyways.
In case you are unaware, the wire that is on the right front goes to the left front coil and left front wire goes to right front coil. Don't ask me why but that is the way they run. And so you don't feel too bad, I goofed up when I put my COPs in too.:biglaugh:

 

[sdt354]

Already replaced the coil with a known good one and it did not fix the problem.
Also, already tried blowing out the missing fuel mixture o-ring with a can of carb cleaner. It's not in there; it's missing.

This afternoon I replaced the pickup coils with some that Sean Morley sent. The bike still won't work with the choke on and now there is a loud pop coming from the left muffler. It popped a few times then the bike died. I have not tried starting it since for fear that I've screwed something up.

Only a good blast of compressed air will get the o-ring out. It's hard to see. Anyway, you need the o-ring in place.

 

[wildweasel_pt]

Is the plug on #1 new? I had a situation when all plugs were firing outside but when fitted i didn't have the fwd cylinders running. Try replacing the plug for a new one and then try again, first with no choke and if it doesn't start try with choke on you may also have a rich condition due to the carbs status (and smelling gas with exhaust popping and black plug). I replaced all 4 plugs and it started at first attempt.

 

[sdt354]

Lot's of plugs get damaged on install using an automotive plug socket.its too long. The socket in the oem tool kit is worth having. 1

 

[fatbiker]

Installed a set of used pickup coils last night and they were worse than the originals. Major backfiring and the instrument lights flickered very quickly. Put the old pickup coils back in and it ran better but still had the original problem of it feeling like it's running on three cylinders. Got advice to disassemble the #1 carb and clean the jet block. I pulled the carb assembly and drained the fuel into a clean container. There was a ton of junk in there! I have no idea how it got in there as I have two fuel filters hooked up. One before the fuel pump and one after. I disassembled the the #1 carb and found more just in there. Cleaned the entire carb including the jet block then reassembled onto the bike. Now it won't idle less than 4K and I cannot get it to sync. The throttle cables are not sticking and I turned the idle adjustment screw till it fell out. Before I put the airbox on I started the bike up and noticed that 3 of the carbs had gas squiring out of the slides but the number 1 carb did not. If I turned the throttle I could see gas squirting out.

Any ideas?

 

[jfeagins]

Did you check the float on the #1 carb for proper operation while you had it off?

Did you hold your (dis-assembled) jet block up to the light and sight down the tiny, tiny holes to be CERTAIN they were both cleared of debris?

 

[alorio1]

If you disassembled the carbs and did not replace the same floats and needle valves that came from each carb ,all the float levels will change. You need to do a wet float level on each of the carbs before reinstalling them. It's best to do a bench sync before putting the carbs back on the bike to get you close enough to hook gauges for fine tuneing. Use a very small drill bit or a very thin wire for the bench sync, I'm assuming you have gauges......

 

[fatbiker]

Yes on both accounts. I reinstalled the carbs and the number 1 cylinder began to work. I could see gas squirting into the throttle body when idling and if I removed the spark plug the bike would run rougher. I took it out on the 'test track' (2 mile long straight section of road with no cops) and the problem persisted and was worse. Every time I take the carbs off the bike and drain the gas I find small black particles and lots of them. If I look at the two fuel filters they are clean. I believe my Uni air filter is crumbling and the carbs are sucking the foam filter material into the jets and clogging them up. It's a brand new filter and I applied oil to it but when I felt it yesterday it was dry and crumbling. I not believe that there is more than one carb affected and they all need to be cleaned. No more Uni brand filters for me!

 

[jfeagins]

I don't believe you can get small bits of air filter debris into the float bowls. The stuff that might ever get past an air filter should mix with the fuel flow at a point where it would be getting sucked either into the idle jet passages (making bad idle) or flowing on through the engine. More likely something like your coasting enrichener diaphrams are coming apart, either from age, or from shooting too much carb cleaner down too many orifices too often. Old fuel line will also contaminate the gas pathways if deteriorating enough. I'm not sure if the rubber inside the choke mechs could come apart and enter into the bowls either.

 

[fatbiker]

You were absolutely right jfeagins. I checked the filter and by rubbing my fingers across is I tried to get the material to flake or crumble off. Didn't happen. I even whacked it on a table to see if bits would come off and they wouldn't. My guess is that the rubber fuel hose is falling apart just as you suggested. Although it seems like a lot of debris to just be the fuel hose. It's coming off tomorrow and I'll let you know what I find.

 

[jfeagins]

DO NOT FORGET to check the coasting enrichener diaphrams - especially if you have been indiscriminately blasting pressurized carb cleaner down into all the nooks and crannies of your carbs - even if you haven't - as they do deteriorate with age. I've been there....the more I tried to clean my carbs, the less my bike wanted to idle, or even run, for that matter. I ruined two of the four diaphrams, and the other two didn't look too good either. For me: new coasting enrichener rubbers + yet another thorough carb cleaning (on the bench), and I had a brand new bike (as soon as I got all the Seafoam run out of the tank and good, pure Dino back in.).

Air filters come apart. They do. But what I meant was that when they do, they will only block small orifaces in the carb throats having to do with air flow - rather than become ingested any place where the bits will ever join into the gasoline inside the bowls.

 

[Bill Seward]

I had problems with my 85 last year, except mine kept puking fuel as well as running badly. I replaced every bit of rubber line from tank through pump and all carb connections, including the molded rubber line shaped like a "T". I was also getting tiny bits of crap out of the float bowls. Since replacement,no more problems. The lines may be falling apart rapidly, and fouling things up faster than you can clean them. Remember also that Seafoam is your best friend when this crap happens..

 

[m-cman]

The older fuel lines were not designed to handle ethanol. Not sure if later ones were either. I would replace all fuel lines as a precaution regardless of year.

 

[blaxmax]

You were absolutely right jfeagins. I checked the filter and by rubbing my fingers across is I tried to get the material to flake or crumble off. Didn't happen. I even whacked it on a table to see if bits would come off and they wouldn't. My guess is that the rubber fuel hose is falling apart just as you suggested. Although it seems like a lot of debris to just be the fuel hose. It's coming off tomorrow and I'll let you know what I find.

Did you ever find a solution?

 

[fatbiker]

My solution was to send the carbs to Dannymax and have him do a thorough cleaning plus replace any parts that needed replacing. I did not replace any fuel lines. The cleaned carbs run perfect now.