Trouble Starting 2001 Vmax

[bboy5818]

Shotgun all four.

Spray compressed carb cleaner ONLY into the jets shown on that link too. A person can spray too much carb cleaner down the wrong passages on these carbs and ruin diaphrams (don't ask me how I know this), and those coasting enrichener diaphrams run about $45.00 per carb nowadays.

PROTECT YOUR EYES WHILE SPRAYING ANY CLEANER AND COMPRESSED AIR, not to mention any painted or plactic parts of the bike that you want to preserve.(please don't ask me how I know this either)

Thank you for those tips, much appreciated. To confirm, it says to blow compressed air down PAJ1 and PAJ2. And to spray carb cleaner down main jet air bleed and idle mixture screw opening. Is that correct?

 

[Fire-medic]

The engine running on 2 vs 4 cyl's shoud be very obvious, the engine won't 'pull' and have rapid acceleration in the rpm range w/the drag of 2 non-firing cyl's. I am speaking of stationary engine operation. Underway, there is no mistaking 2 vs 4 cyl operation on a VMax!

Removing # 1 or #4 lead will transform your 'twin' into a single cyl and we all know whata Briggs & Stratton sounds like! The engine would probably die if you allowed it to drop to idle, because of the 3 inoperable cyl's drag.

I think you probably need a disassembly & thorough cleaning of the carbs, to get them functioning correctly. Since grounding the plugs produces sparks, it sounds like the fuel/air mix is grossly out-of-whack.

Update... So, I changed the plug on cylinder#2, which is the one that the pipe was running cool and still no change. When I pulled the plug that was in there the electrode was black and a little wet. Since I have not figured out the problem, I also decided to check all the cylinders for firing. I came to the conclusion that the engine may only be running on two cylinders, #1 and #4. The reason being that I can pull the plug wires off of cylinders #2 and #3 with no change to the engine rpm. However, if I pull off plug cable for cylinder #1 or #4, the engine rpm drops and may even stall. I have a spark to all plugs, I checked them with the plugs out and the plug grounded. The spark was not necessarily blue, more yellow/orange, but they all looked the same. I'm guessing there is still an issue with the carbs? Something must be blocked? Would it be a waste of time trying to sync the carbs if all 4 cylinders are not firing? All thoughts and suggestions are welcome and aappreciated. Thanks. Bill

 

[bboy5818]

The engine running on 2 vs 4 cyl's shoud be very obvious, the engine won't 'pull' and have rapid acceleration in the rpm range w/the drag of 2 non-firing cyl's. I am speaking of stationary engine operation. Underway, there is no mistaking 2 vs 4 cyl operation on a VMax!

Removing # 1 or #4 lead will transform your 'twin' into a single cyl and we all know whata Briggs & Stratton sounds like! The engine would probably die if you allowed it to drop to idle, because of the 3 inoperable cyl's drag.

I think you probably need a disassembly & thorough cleaning of the carbs, to get them functioning correctly. Since grounding the plugs produces sparks, it sounds like the fuel/air mix is grossly out-of-whack.

I drained the float bowls and there was definitely gunk in there. I think you're right, the carbs need some more cleaning. On the plus side I checked the float fuel levels and they all looked pretty good, so the floats are not stuck. I'm going to clean the carbs again.

 

[bboy5818]

Another update... Ok, so as I mentioned I checked the float bowl fuel levels and they all looked okay. I drained them all, I replaced the fuel filter, I did the Peashooter method, I ran two tanks through with Seafoam, I did the Shotgun carb cleaning method and I synched the carbs. The results have been that it does run and idle a little better and starts right up if its warm but cold starting is still an issue. Wtf!? The only thing left I can think to do is completely disassemble and clean the carbs again and hope that magically fixes the problem. Any thoughts?

 

[Traumahawk]

I'm wondering now if its something simple? To start mine....even on very cold days, 1/4 to 1/2 choke, I twist the throttle 1 time, to get fuel into the cylinders, and then start it.

If you dont twist the throttle, then it has to try and pull fuel into the cylinders, and it needs to be richer.....IE the reason for the choke.

Hope this helps.

 

[jfeagins]

Hard cold starting, when you KNOW the battery is in primo condition, and you know the carbs to be synced and adjusted pretty darn close, can indicate voltage problems with your CDI box during cranking.

When mine did that (off & on for years before finding this forum) I was ready to pull my hair out. Mine had great battery condition with plenty of cranking going on, but starting first thing in the morning. Come back home for lunch, check it, and it'd start on the first spin. WTF. With mine, even though the battery would spin over easy enough, the voltage was falling below the CDI's minimum threshold ONLY WHILE CRANKING. I had to go through the charging system on my bike, and finally did the bigger battery box mod, to install an even bigger battery for better CCA to maintain proper voltage WHILE CRANKING. I had noticed, prior to fixing mine's problems, that the only time it would try to fire was at the moment I let go the starter button, and while the motor was still barely spinning, but starter was no longer using amperage.

By connecting up your volt meter to the battery DURING COLD START UP, you should be able to check this easy enough. At the very least, if it's not your problem, you can eliminate voltage/CDI problems from your list of possibles.

 

[Lew L]

It's my understanding that the enrichening circuit dosen't work with the throttle plates open even a little. The enrichening circuit( wrongly called a choak) needs vacume to work and it's small. With an open throttle when first starting there is not enough vacume to make the enrichening circuit work.
Previous advice is all good. A strong blue spark is necessary---- we are looking a spark in the air----In the cylinder, under pressure, with fuel ---- a weak spark wont ignite the fuel.

And last---- How about compression??

Lew

 

[bboy5818]

Hard cold starting, when you KNOW the battery is in primo condition, and you know the carbs to be synced and adjusted pretty darn close, can indicate voltage problems with your CDI box during cranking.

When mine did that (off & on for years before finding this forum) I was ready to pull my hair out. Mine had great battery condition with plenty of cranking going on, but starting first thing in the morning. Come back home for lunch, check it, and it'd start on the first spin. WTF. With mine, even though the battery would spin over easy enough, the voltage was falling below the CDI's minimum threshold ONLY WHILE CRANKING. I had to go through the charging system on my bike, and finally did the bigger battery box mod, to install an even bigger battery for better CCA to maintain proper voltage WHILE CRANKING. I had noticed, prior to fixing mine's problems, that the only time it would try to fire was at the moment I let go the starter button, and while the motor was still barely spinning, but starter was no longer using amperage.

By connecting up your volt meter to the battery DURING COLD START UP, you should be able to check this easy enough. At the very least, if it's not your problem, you can eliminate voltage/CDI problems from your list of possibles.

I measured battery voltage while cranking at start up and it did drop, I have since charged the battery to fullcharge. Battery is only 6 months old. I ddon't see how its battery voltage dropping low during start up, because as soon as i add a shot of fuel to the air intake it starts right up. Sometimes, when cold it will fire a little but then dies, then it won't try to fire unless i put a shot of gas in the intake. I know the choke is really an enrichment circuit. I guess at cold starts its just not sucking fuel. I just can't figure out why. Seems this bike needs to be primed in order to start when cold.

 

[bboy5818]

It's my understanding that the enrichening circuit dosen't work with the throttle plates open even a little. The enrichening circuit( wrongly called a choak) needs vacume to work and it's small. With an open throttle when first starting there is not enough vacume to make the enrichening circuit work.
Previous advice is all good. A strong blue spark is necessary---- we are looking a spark in the air----In the cylinder, under pressure, with fuel ---- a weak spark wont ignite the fuel.

And last---- How about compression??

Lew

For lack of anything else to do, i will check compression. However, I can't imagine its a compression issue given the fact that this bike only has 2500 miles on it.

 

[Redbone]

Starting here in below 40* weather I use full choke then hit the starter. If she doesn't fire on first try I add a small bit of throttle which has always done the trick. Like Lew mentioned you need to be sure your getting a strong spark to fire the fuel, especially so in the cold.

 

[bboy5818]

Starting here in below 40* weather I use full choke then hit the starter. If she doesn't fire on first try I add a small bit of throttle which has always done the trick. Like Lew mentioned you need to be sure your getting a strong spark to fire the fuel, especially so in the cold.

I am in Florida, and its rare that it gets below 70 even in the winter. I am having these cold start issues with an outside temperature of around 70 F.

 

[Hellboy]

What weight oil are you using? Oil is thicker and its harder for your engine to crank over when cold and much thinner and easier when hot, Hence 10-40W. 10 when cold 40 when hot, basically. When my battery gets older and weaker my bike would never start up when in the shed. I would always roll it out into the sun to sit for 30 minutes or so and it would fire right up. With a good strong battery, I don't. If you have one, try hooking up a battery charger/ jump starter to it and then see if it fires up when cold. If it does then it's your battery, which could also mean charging system if you battery is only 6 months old.

Matt