Banging my head over here

[Demonsinmysemen]

Hello, everyone! Jon, here, again! I'll just get right to it. Back in November my 2007 Vmax was having some starting issues and I went back to school after the holidays so I didn't have more than a few hours a month to work on her. Summer is here, so I've got some free time. I have done as follows: pulled off the carb, cracked it in half and cleaned it. Changed the pickup coil, changed the spark plugs and gapped accordingly, swap the valve cover gaskets, siphon the tank. Last week, I finally got her running decently well, I felt. I got a carb tuner and synced the carbs, drive it around, and it ran better than it has ever run before(not to say that it ran poorly before) almost no back fire, no hick ups. So, i went back home, grabbed my helmet and went for another ride. All was well until I got to a stop sign, the bike started to idle really low and it shut off. It cranks right up, however, at low revs, it sounds like only the left side of the motor is running, I even put my hand outside of both exhausts and there is a big difference from the left. Making me think there's a cracked cylinder or something. Everytime I start it when it's cold and on choke, it seems to run perfectly fine. Plenty of power from both sides. The one thing I do remember is, when I was tunning it with the carb sync, carburetor#4 need to be tightened almost completely to sync with the other three. Sorry for the rant, I didn't want to miss anything. Any help would be appreciated, thank you!

 

[maleko89]

When you cleaned the carbs, did you remove the pilot fuel jets and clean? Did you replace the fuel filter? Try draining a float bowl and see if any gunk/rust/water come out instead of fuel.

Mark

 

[Traumahawk]

Sounds like its time for a shotgun. Its a very easy procedure to to, and if you can use hand tools at all, then you can do this. This will walk you thru it step by step.

http://vmax.lvlhead.com/tips/shotgun.htm

 

[Demonsinmysemen]

When you cleaned the carbs, did you remove the pilot fuel jets and clean? Did you replace the fuel filter? Try draining a float bowl and see if any gunk/rust/water come out instead of fuel.

Mark

I did replace the fuel filter. Not sure if maybe I got the wrong one? I didn't see anything come from the float bowl. Suggest doing it more than once?

 

[Demonsinmysemen]

Sounds like its time for a shotgun. Its a very easy procedure to to, and if you can use hand tools at all, then you can do this. This will walk you thru it step by step.

http://vmax.lvlhead.com/tips/shotgun.htm

I have heard of this. Seems like everyone has to do it at one point in their Vmax life. The jets seemed pretty clean

 

[Demonsinmysemen]

I did replace the fuel filter. Not sure if maybe I got the wrong one? I didn't see anything come from the float bowl. Suggest doing it more than once?

Oh, and I removed every jet that seemed remove able

 

[Traumahawk]

It's very easy for a single piece of crud to get caught up in the pilot jets.....because they are VERY little. I had a pilot jet get clogged after I changed the jets.....flipped the carbs over.....and a bit of crud went into a jet.

 

[G max]

Jon did you check the coil voltage and you should clip off a 1/4 inch on both ends of your spark plug wires, also check your wires for corrosion.

 

[Demonsinmysemen]

Jon did you check the coil voltage and you should clip off a 1/4 inch on both ends of your spark plug wires, also check your wires for corrosion.

Yeah, I checked it. That's why I ended up changing it. It seems to run well. Clip the ends? Hmmm. That's definitely interesting

 

[Demonsinmysemen]

Sounds like its time for a shotgun. Its a very easy procedure to to, and if you can use hand tools at all, then you can do this. This will walk you thru it step by step.

http://vmax.lvlhead.com/tips/shotgun.htm

What about sea foam?

 

[Traumahawk]

What about sea foam?

For sea foam to work, you have to get it into the jet. Its the jet is clogged, the sea foam cant get into the jet. This way you are just blasting air/carb cleaner into the pilot jets and getting them clean.

 

[Demonsinmysemen]

For sea foam to work, you have to get it into the jet. Its the jet is clogged, the sea foam cant get into the jet. This way you are just blasting air/carb cleaner into the pilot jets and getting them clean.

Thanks, a lot! I'm trying to take the tank off, clean it and change the fuel filter

 

[Demonsinmysemen]

So, I couldn't get a hold of a air compressor, but I took the carbs and they were full of rust and gelled up gasoline. I did a rust treatment on the tank, changed the fuel filter, changed the jet block gaskets and cleaned the carbs new gas. Although, I did use a outboard marine fuel filter. Don't know if that matters. The bike runs wonderfully, have all the power and it's crisp....for about 10 mins or so. The bike starts to drastically lose power and shuts off. After about a minute, it goes back to having the power and runs for a while and does the same thing. Any ideas?

 

[user 16790]

did you clean out the hose between fuel filter and carbs

 

[Demonsinmysemen]

did you clean out the hose between fuel filter and carbs

Yeah, well, I sprayed a good amount of carb cleaner. I just took a look at the fuel filter box that I bought from advance and it says "for outboard engine use only!" Normally I'd take that as is but I'm sure have used this filter on some of my dirt bikes in the past. it's really strange how well it runs and then starts to die out, I'll rev it as it slowly dies down. Park for a bit and start it right back up.

 

[Traumahawk]

Yeah, well, I sprayed a good amount of carb cleaner. I just took a look at the fuel filter box that I bought from advance and it says "for outboard engine use only!" Normally I'd take that as is but I'm sure have used this filter on some of my dirt bikes in the past. it's really strange how well it runs and then starts to die out, I'll rev it as it slowly dies down. Park for a bit and start it right back up.

That sounds almost like a stuck float, or possibly the vent for the gas tank is clogged up. When it dies, take the gas gap off, and see if there is a whoose of air.

 

[Demonsinmysemen]

That sounds almost like a stuck float, or possibly the vent for the gas tank is clogged up. When it dies, take the gas gap off, and see if there is a whoose of air.

Stuck float? Ahh, crap, hope not. So, if there's a woosh of air when I open the gas cap, it's possible that it's a plugged vent hose? It's pouring rain by me, hopefully I can get it diagnosed by tomorrow. I'm dying to ride her.

 

[[email protected]]

o, if there's a woosh of air when I open the gas cap, it's possible that it's a plugged vent hose? It's pouring rain by me, hopefully I can get it diagnosed by tomorrow. I'm dying to ride her.

Yes. Or faulty tip over valve

 

[Demonsinmysemen]

Yes. Or faulty tip over valve

Is that something that would have to be switched out? Also, any advice on the fuel filter?

 

[sdt354]

Is that something that would have to be switched out? Also, any advice on the fuel filter?

Fram, Purolator #F21124 both fit nice in the holder. $5 at Advanced Auto. Or $21 for an OEM filter, probably made by Fram anyway. Yearly change is prudent. I was surging the other day. Took the filter out and could hardly blow through it. Shotgunned the carbs, new filter and back on the rode running great.