General starting issues

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I'd suggest giving the carbs a thorough cleaning.

You said this was just recently done. If that were the case, the A/F screws wouldn't be an issue right now.

These carbs are finicky. Tear them down completely. Inspect everything. Replace what is worn with Mikuni parts.

You said the bike has been sitting. How clean is the fuel tank, the fuel lines, the pump? These are all quite common issues with an old vmax.

 

[Fire-medic]

Bonus points if you can name the bike that cyl head & valve cover belong-to.

This is how you have to be prepared for using your VMax, a spare set of clean carbs to swap-in.

 

[Jhbox13]

Tank is surprising clean, lines are good and pump works like a dream. I think it had been sitting about a year.

I wen through it once, cleaned up everything but the pilot screw, just forgot it frankly. I'll give the whole thing another run through, just check my work again.

 

[Jhbox13]

I got the pilot a screws out as well, it's amazing what a little canned air will do, no fire needed thank goodness

 

[D-Max2012]

Great that you found the screws.

I tell you, it seems like it's nit getting gas, at least that's how it's acting to me.... but i know it is. Even if it wasnt, the starter fluid I gave it would make something happen.

I agree with your statement about the starter fluid. Even if only for a few rotations..

Keep us updated.

 

[Jhbox13]

I ordered the new pilot screws a couple of days back, I should have them this weekend or early next week. Not much to do for now besides sit on my hands I guess.

 

[goddam]

sounds like the plug caps are in the wrong position which would be hard to do but you talk about changing the pickups i would check that you have them the right side because if they are firing wrong the motor will never start but it will backfire

 

[Jhbox13]

sounds like the plug caps are in the wrong position which would be hard to do but you talk about changing the pickups i would check that you have them the right side because if they are firing wrong the motor will never start but it will backfire

The pickups can only be mounted one way. The length of the wires makes it impossible to mix them up unless you literally cut the harness and extend the shorter ones. Check out the pic, you'll see that the long one is about 4x longer.

 

[D-Max2012]

plug caps

He's not referring to the pulser pick-up coils in your picture. He's referring to the coil plugs that connects to your spark plugs.

 

[Jhbox13]

sounds like the plug caps are in the wrong position which would be hard to do but you talk about changing the pickups i would check that you have them the right side because if they are firing wrong the motor will never start but it will backfire

This

 

[Jhbox13]

So I got my pilot screws, put them in at 2 turns. Install the carbs, and no change. The occasional backfire with starter fluid.

I pulled the plugs and check the firing order. 4-1-2-3.

Now does anyone know for sure what the firing order is on these guts? I had seen 1-4-2-3 somewhere, but can't find it now. Any help would be appreciated, I'm pulling my hair out here.

I have the air box off, but surely that isn't interfering enough for the bike not to run...

 

[sdt354]

1342 is the firing order.

 

[one2dmax]

So, typical no start problems with the 85-89 models.
Bad Starter Relay (which you can simply unplug to bypass for now)
Bad CDI box (which can randomly work or not)
Bad Carbs

Other common issues
Bad Starter which symptoms are usually slow crank when warm/hot
Starter Clutch (usually sounds like box of rocks sound)
Bad Battery (which even if testing good if the voltage drop is enough there isn't enough left to "turn on" the cdi box though the engine cranks fine)
Bad Coils (which usually just leak spark randomly)
Carbs (did I mention that most people have no clue how to properly set them up)

 

[Jhbox13]

Please correct me of I'm wrong on cylinder numbering

1-rear left
2-front left
3-rear right
4-front right

 

[sdt354]

Please correct me of I'm wrong on cylinder numbering

1-rear left
2-front left
3-rear right
4-front right

Correct.

 

[Jhbox13]

Well, I got it going for about five seconds before i hit the throttle and it died. I fiddled with mix between 2 and 5 turns, but couldn't hit that sweet spot again. Not sure what the deal is, but maybe it's one of these "try until it works, then it'll work" bikes.

On a side note, is my air box the only one that is an absolute headache to get down on the carbs? All the bodyweight and lube in the world isn't doing it, and the darn thing just won't go down onto the #1 carb

 

[D-Max2012]

On a side note, is my air box the only one that is an absolute headache to get down on the carbs? All the bodyweight and lube in the world isn't doing it, and the darn thing just won't go down onto the #1 carb

First few times I removed the airbox, it was a little challenging to get it back down (and I'm a big guy), but after feeling how much force is needed and making sure the clamps are nice and loose, to allow the rubber to stretch over them, it became easier to handle. While applying pressure, take a look at what's binding up.. Heavy duty bungee cords over the airbox helped me when I 1st started working on her. If #1 is being a PITA, wiggle that one into position 1st, and see if the others fall into place.

Also, before I knew my gas tank was fouling up my jets and my bike would stumble around 4-5K I put a piece of duct tape, covering 1/2 of each side of the airbox opening. At the time, I found that the mixture was off (no matter where I set the screws), and too much air was getting in (or not enough fuel).. When I cut the air down, it allowed the bike to run better between 4 - 5K..

This duct tape test, helped me diagnose the fuel / air mix problem.

After finding out that the ethanol laced fuel, was rusting my gas tank and producing Micro Foreign Matter (MFM), and clogging my jets, I took the time money and effort to seal my tank. I was too pissed off by then, to have ANY MFM in my system:bang head: . So I broke-down and ultra sonic cleaned out all carbs parts. Disassembled and cleaned out the fuel pump. I even went as far as to clean out all fuel lines. Then I ran 1/2 can of Seafoam in my gas tank at fill-up. On the 3rd fill-up (1.5 cans of Seafoam by now), I noticed it was pulling stronger than ever, and that stumble was gone:clapping:. I removed the duct tape and its been great ever sinceunk:.
I had a hell-of-a time with this baby.

 

[Jhbox13]

First few times I removed the airbox, it was a little challenging to get it back down (and I'm a big guy), but after feeling how much force is needed and making sure the clamps are nice and loose, to allow the rubber to stretch over them, it became easier to handle. While applying pressure, take a look at what's binding up.. Heavy duty bungee cords over the airbox helped me when I 1st started working on her. If #1 is being a PITA, wiggle that one into position 1st, and see if the others fall into place.

Also, before I knew my gas tank was fouling up my jets and my bike would stumble around 4-5K I put a piece of duct tape, covering 1/2 of each side of the airbox opening. At the time, I found that the mixture was off (no matter where I set the screws), and too much air was getting in (or not enough fuel).. When I cut the air down, it allowed the bike to run better between 4 - 5K..

This duct tape test, helped me diagnose the fuel / air mix problem.

After finding out that the ethanol laced fuel, was rusting my gas tank and producing Micro Foreign Matter (MFM), and clogging my jets, I took the time money and effort to seal my tank. I was too pissed off by then, to have ANY MFM in my system:bang head: . So I broke-down and ultra sonic cleaned out all carbs parts. Disassembled and cleaned out the fuel pump. I even went as far as to clean out all fuel lines. Then I ran 1/2 can of Seafoam in my gas tank at fill-up. On the 3rd fill-up (1.5 cans of Seafoam by now), I noticed it was pulling stronger than ever, and that stumble was gone:clapping:. I removed the duct tape and its been great ever sinceunk:.
I had a hell-of-a time with this baby.

I appreciate the insight. I'll give the air box another go, I may try my old rachet strap method that I use for easing carbs onto the intake boots.

I think my tank is pretty clean but I'll give it a whirl just to make sure it's good. It seems lie my bowls are filled, as they flow freely whenever I loosen the drains but you never know.

 

[D-Max2012]

I think my tank is pretty clean but I'll give it a whirl just to make sure it's good. It seems lie my bowls are filled, as they flow freely whenever I loosen the drains but you never know.

Just an FYI,
After cleaning out my tank, at least 8 times (before I coated it), It looked clean also.
The thing that pissed me off was, I still had a stumbling issue. after being fed up, and pulling the tank out to coat it,, I pulled the carbs again..
When I opened them up, that damn rust was back. This was not even a full gas tank use, before the rust was back.
Note, I pulled the carbs at least 9 times, totally dissembling them and cleaned with tooth brushes, jet hole cleaners, and carb cleaners.
On the 9th time, I put all the parts in an ultra-sonic cleaner bath. The ultrasonic cleaner removed **** that would have never been able to remove by other means. The water and Simple Green mixture was so muddy looking when I was done. I noticed so many little specs of crap in the basin when cleaning it, I decided to run the parts thru again. 2nd time, the mixture was almost clear green. EVEN AFTER ALL THIS, only the use of the SeaFoam got those micro obstructions out of my carbs.

So I found out thru a lot of toil and anguish, that "looking clean" and being clean, is two totally different animals when it comes to the fuel system on these boys.

Also, with that said,, draining the bowls is fine to see that they being filled.
But, what about the fuel that's in the bowls, getting thru the jets easily, to be mixed with air at the correct ratio?

 

[Jhbox13]

I definitely give it a good hard look. I haven't noticed any kind of sediment in my bowls or in the filter, but I'll check it out.