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Jhbox13

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Hey all. Just got done replacing the pickupcoils for my '85, which thankfully breathed new life into my #2 cylinder. I took the carbs off and found them to be a bit fouled, no more than I would expect from a bike thats been sitting up a few years though. I ran through the carbs and have fuel, spark and compression to all four cylinders.

Now heres the situation: for the life of me I cant get this darn to thing to crank. I've been doing bikes of various kinds for years, but I've realized that the vmax is a special snowflake in the two-wheeled world, so maybe I'm missing something here. Hell, it took a bit for me to figure out what that switch on the right handlebar was, makes since I guess but it feel weird for a fuel reserve switch.

Any misc advice would be appreciated. Like I said, fuel, spark and compression check out. I even stuck a car battery with 14v on it to give it an extra kick. I'll get a bit of backfire every now and then but thats it.

Maybe its this vboost thing? I tried to check out the sticky but the link/pic is dead. Same for the a/f mix screw sticky.


Hopefully there is some magic idiot switch that I'm missing.
 
Sidestand switch. They stick once in a while, and that'll stop the starter. Try jumping across the relay under the seat. Clean connection on starter motor.
 
Sidestand switch. They stick once in a while, and that'll stop the starter. Try jumping across the relay under the seat. Clean connection on starter motor.

My apologies, I thought I had made it clear that I was getting spark to each cylinder and that the bike has no trouble turning over. The issue is with ignition not with turning over. Like I said, the best I am getting is backfire while trying to start.
 
You said for the life of you, you couldn't get the bike to crank. I assumed by crank, you meant the starter turning the engine over.
 
The bike will start regardless of V-boost position. You verified fuel right to the intake manifolds?
Check the pick-up wiring at the plug again.
 
The bike will start regardless of V-boost position. You verified fuel right to the intake manifolds?
Check the pick-up wiring at the plug again.

I'm definitely getting fuel, I get a nice puff of gas mist every now and then. I'm getting soark, so what are you meaning by "check" the wiring?
 
...have fuel, spark and compression to all four cylinders.

If you have that then it will start assuming the spark is at the right time and the air and fuel are in the correct ratio.

Now here's the situation: for the life of me I cant get this darn to thing to crank.

Please clarify, do you mean that the engine will not turn over or it turns over but will not fire up (I suspect the latter).

...I've realized that the vmax is a special snowflake in the two-wheeled world,

It is special but not in the way you imply - the motor works on exactly the same principle as other four stroke petrol engines before electronics took over.

Hell, it took a bit for me to figure out what that switch on the right handlebar was, makes since I guess but it feel weird for a fuel reserve switch.

If all else have failed read the handbook....

You need to go over what you have done recently as your issue is most likely there.
Have you checked that the wires from the pick-up coils go to the correct wires in the loom; that the plug leads are attached to the correct cylinders?

That you haven't inadvertently pinched the pick-up wires.

That all three blanking plugs are on the inlet stubs and the vacuum advance pipe is attached?

If, when inspecting the carbs, was any dismantling involved and if so was everything put back correctly?
 
Just got done replacing the pickupcoils for my '85, which thankfully breathed new life into my #2 cylinder. I took the carbs off and found them to be a bit fouled, no more than I would expect from a bike thats been sitting up a few years though.

Trying to understand what's going on here.

It sounds like the bike was running but #2 cylinder wasn't firing.
Your replaced the pickup coil and then #2 cylinder worked buy you felt the carbs needed to be cleaned.

You took the carbs off, cleaned them , reinstalled and now it won't start?
 
Ok, lets start with the background.

I just bought this bike from a guy about two weeks ago. He said he had replaced the stator, after which the bike would not run. I discovered that the #2 cyclinder was not getting spark, and after narrowing it down to the pickup coils I discovered that the #2 coil had a massive crack in it. Replaced it with one from Morely's Muscle, and my #2 was a go.

I went to check the carbs and discovered that two were getting no fuel at all. Pulled the carbs, gave them a good cleaning, all were mildly fouled and the two were pretty nasty. A few hours later and I have them cleaned and back on the bike. The are getting fuel.

I checked compression. I don't recall exactly but it was between 100 and 150 on all cyclinders.

The engine DOES TURN OVER. It'll occasionally backfire, but that seems to be the most ignition it is wanting to do.

The pickup coils can only go in one way and the plug can only go on one way, so the pickups are not crossed. As for plug wires, I assume that they were correct when I got the bike, but maybe the guy I got it from crossed them. Seems like each plug wire can only reach one plug though.

Carbs were reassembled correctly, though these are a little different I've handled many in my time.

There is one thing though that you said that I'm curious about MaxMidnight: What in the heck are you talking about when you say."
That all three blanking plugs are on the inlet stubs and the vacuum advance pipe is attached?" Maybe its an issue of semantics but I have no idea what you are talking about.
 
Also, is there a manual available on this forum somewhere? I took a look but didn't find much
 
Please note: IF you had to mess with the pick-up coil wires (Put new connectors or swap wires), You may have them in backwards.. I know for a fact that on my 91, they are polarized.
The color wires that came with my replacement pickup coil were Blue and Green,, not Black and Orange like the stock part..

When I 1st put it in there, the bike would crank fine, but it would not start.
You would get POP here and there and a loud ping from the left cover area.

I figured, what the hell,, flip the wires. One button press and,, Vroooom.. :)
 
It sounds like he is talking about the coils for the plugs. Not the pick up coils for the stator. The front two coil wires go to the opposite side of each other. So check them.


Sent from my iPhone using Tapatalk Pro
 
It sounds like he is talking about the coils for the plugs. Not the pick up coils for the stator.
Reason for mentioning that was, He stated that the original owner, replaced the stator (which means, he was near the pick-up coils also).. After which, the bike would not run.
 
@dmax
Pickups on my 85 are different than yours. Due to the length of the cables it is actually impooible to install them backwards without tearing 5he harness apart. The plug is a non symmetrical five prong, so no way to plug it up wrong.

@set
Harness is good, if it was pinched I would have spark issues. Spark is good xr.

@hello
Front plugs are on the opposite side coils, rear plugs on the same side coils.


What are these blanking plugs, inlet stub and vacuum advance pipes that were mentioned? Part fische #?
 
Blanking plugs are just the rubber caps that cover the synchronization spigots on the intake manifolds. 3 manifolds get a cap. One (front left) connects to a hose.


Sent from my SM-G930V using Tapatalk
 
Going by all your previous statements with the symptoms you've described, can you be 100% sure that the wires leading from your pulser-pickup (that's inside the stator cover, not the big coils that attach to the plugs), are wired correctly?.
Sub Meaning, did the previous owner mess with, or put a new connector on, when he changed out the stator?

You stated, you even connected a car battery to get more power, but you would get only an occasional backfire. Same thing happened to me while diagnosing my, no start situation. But, I found it quickly because I did not have a color wiring diagram (at the time), to see that the pulser wiring was actually polarized.

You also stated "Due to the length of the cables it is actually impossible to install them backwards without tearing the harness apart".
Correct me if I'm wrong, but I thought the 85 pulser-pickup connector was a multi connection 5 wire port, that's under the seat. I have a feeling we're referring to two different things.

I was just wondering if the previous owner messed with pusler pick-up wires at all because you stated, the PO said that the bike would not run afterwards.
85 coil pick-up.jpg

Note: If I sold my 91, with my reversed wiring, because my bike would not start, the next owner would not get it running either, if he did not know that I flipped the wires..

Even though your 85 has dual pulsars, your symptoms sounds exactly like my own.

Good luck bud..
 

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