Carburetor idle circuit cleaning

[dannymax]

I woke up one morning and my Vmax ran like crap. It ran perfect the day before. Had to keep the choke on to keep it running. Got on this webpage and read about the Shotgun. Did it and now the bike runs great again. A month later the bike still runs good.

BTW. I went ahead and pulled the #1 and #2 air jets even though it didn't look like I really needed to. I drilled out the idle jet plugs. The jets are actually quite a ways up in there, so not too close behind the plug. I set the idle jets about a 1/4 turn richer. Seems to have a smoother transition, but could be just because it's cleaned up inside now.

Just one more vote for the Shotgun.

thanks to whomever posted this procedure.

Smackdown

If you haven't already done so, you might improve it further by syncing.

 

[balderon]

I've done it and it works great. it is also a good time to check your slide diaphragm for any rips or tears. 2 of mine had small rips in them which I was able to repair with a little bit of silicone. They are pretty expensive to buy.

Over the weekend I discovered some small tears in a couple of my '85 diaphragms. Before I replace mine, have you had an opportunity to examine how well the repairs have held up over time?

Thanks
Jeff

 

[Buster Hymen]

Over the weekend I discovered some small tears in a couple of my '85 diaphragms. Before I replace mine, have you had an opportunity to examine how well the repairs have held up over time?

Thanks
Jeff

It held up OK, and it usually got me through the season (note I can't ride year round as you can) but eventually it became a mid season fix or a multi time season fix. Honestly, for the age of the bike, all the rubber pieces are going to be in sad shape. Think about the condom you bought in Grade 7 and carried around until Grade 11! :rofl_200: . I delayed it as long as possible but the difference in how the carbs and the airbox fit together were amazing. Also I found the bike ran crisper when I changed all the diaphragms.

 

[balderon]

It held up OK, and it usually got me through the season (note I can't ride year round as you can) but eventually it became a mid season fix or a multi time season fix. Honestly, for the age of the bike, all the rubber pieces are going to be in sad shape. Think about the condom you bought in Grade 7 and carried around until Grade 11! :rofl_200: . I delayed it as long as possible but the difference in how the carbs and the airbox fit together were amazing. Also I found the bike ran crisper when I changed all the diaphragms.

I am the original owner and very pleased with the my '85, only 54k miles! :thumbs up: I have just started looking for any safety critical problems and I think I'll wait to replace the 'nice to have' parts until I have a complete assessment. Amazingly, much of the rubber pieces are in pretty good shape... so far.

Thank you for the information.

Hummm, I'll have to say most of us didn't allow any condoms to age! :hihi:

 

[vmax626]

John, glad your bike is running tip-top!

Hello Mark,
Please excuse my ignorance but, could you tell me what the shotgun proceedure is ?

thank you,

Dave.

 

[maleko89]

Sure, here ya go.

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

 

[Kratos]

:bang head:I?ve got an 07 MAX with only 1445 miles on it. I bought it used and the previous owner let it sit for most of its life, as you can tell by the mileage. I originally had an idle circuit problem. Every time I started the bike it would jump to 4K or more, even when warm, as well as hang at 4K or so when I came to a stop. Also had steady cruise problems (pops, crackles, and sputters), but the bike seemed to run great under acceleration. I did the peashooter and shotgun, now it starts and idles great, but still runs like crap at steady cruise (pops, crackles, and sputters) and NOW, under acceleration (has no balls whatsoever). I have added a K&N air filter, Supertrapp slip-ons with no discs and open end caps, new plugs, and wires. I?ve done the peashooter once, the shotgun twice, ran a couple tanks with Seafoam, and one tank with Techron, nothing seems to help. Main jets are stock, needles are stock, fuel mixture screws are 3.5 turns out, and I sync the carbs each time I make an adjustment to the a/f screws. It seems to be getting worse. It did seem to help slightly if I turned the a/f screws out to richen the mixture, but now it has no affect on the steady cruise popping and sputtering. I did notice, while doing the shotgun on carb #1, that when I shot air into the a/f screw hole, I could hear a rattling sound. The only thing I can think of that would rattle would be the float, is it normal to hear the float flutter while blowing air into the a/f screw hole? I guess if there was no fuel in the bowl, it would be free to rattle. When I took the plugs out, they all looked pretty much the same, grayish color. Since it has been cold here in southern Indiana, I have not gotten to ride the bike very much since I got it at the end of last season, so maybe a few longer trips with Seafoam/Techron in the tank will do the trick??? I keep hoping that like some of you other guys the problem will just suddenly go away, but I?m not feeling too lucky.:confused2:

 

[maleko89]

Trying adding some discs. Open end caps only is pretty restrictive. I recommend 6-8 discs with the open caps. If it still pops for steady cruise and seems to lack power then would check fuel filter, air filter, and make sure all 12 rubber boots are in good shape and tight. Also make sure you sync caps are on tight and the hose for the #2 carb is on correctly. The arrow should point up. Drain your float bowls and see what the fuel looks like. It should be clear with no bits of dirt/rust coming out. If that fails it might be worthwhile to take a peek inside and make sure all the little holes are clear. I'll speak for Lankee and recommend you check your floats while your carbs are off.

 

[Kratos]

Thanks, I'll try adding some discs tomorrow and checking the fuel filter. I checked the #2 carb hose and it is on correctly, and all the sync caps are on all the way and are tight.

 

[GPrider]

I have a 95 I bought about this time last year and it would idle and run right with the choke constanly on. I did the shotgun on it and the results were great. It still idles good after the warm up with the choke on. After the warm up and the choke off it seems to lose power from a cylinder as you crack the throttle just off idle, but then is fine once it gets up to 3 or 4 thousand rpm. It's just barely noticeable, but bothers me some. I ran one tank with seafoam thru it, but from what I've read here I should probably run a few more. When I did the shotgun, I got to the point of removing what he called the idle mixture screws. I turned them in as instructed to count the turns so I could reinstall them in the same position. One was so full of crud I couldn't do that, so I unscrewed it and took it out without knowing the facory position. When I installed it back in the carb,after cleaning the crud out, I set it close to what the other ones were. Just wondering if one of these scews is not set right if it could cause the stumble just off idle when you start to open the throttle. Also is there any way to find out where they are supposed to be set. I just went through the carburetor part of my service manual and found nothing, except that Yamaha calls it a pilot screw. Any knowledgable thoughts would be appreciated.

GP

 

[naughtyG]

To set them up 'properly' you need an exhaust sniffer that will tell you exactly what your air/fuel mixture is made of. Usually out of reach of the average home mechanic, these are found (most of the time) where people have dynos. Expensive.

Another way is to use a laser thermometer to measure header temperature, but that's apparently difficult and unreliable.

Some people say you can set them by listening to engine revs, but I think that's only possible on a single or twin engine. On a V4 like ours, when I tried I could not tell. At all.

We usually set them to 2.5 turns out as a start, and go from there. If it feels/smells rich go in a little, maybe 1/4 to 1/2 turn at a time. If it's lean, go the other way (out).

Your spark plugs tell a great story as to the lean or rich state of your mixture. Light tan is what you're looking for on the electrodes.

 

[GPrider]

Tanks. I'll try to do a little slight adjustments and see what it does.

 

[vmax2extreme]

Been reading the forums here and I know the shotgun, but what is the peashooter? Can someone explain it or give me a link to the process.

Thanks,

Mike

 

[vmax2extreme]

Been reading the forums here and I know the shotgun, but what is the peashooter? Can someone explain it or give me a link to the process.

Thanks,

Mike

Nevermind, found it on Paul Czernicks site:

http://home.comcast.net/~onlyone12/carbs1.htm

 

[choctaw]

Need help guys,,,just got my 2000 in and won't idle ,runs rough,backfiring feels like its kicking in and out ,,,in and out ,,,and my Vboost only works about a third of the time,,,,that battery was completly dead so replaced and am currently running seafoam through it but I don't get the Vboost problem any info would be greatly appreciated:bang head:

 

[choctaw]

Oh yeah and it is rich as hell ,,,,burns your eyes while reving and forced idle:bang head:

 

[dannymax]

Did you recently do some work on the carbs or did this start up without warning?

 

[choctaw]

I just bought it from Kaboom and got it in Tue.

 

[dannymax]

I just bought it from Kaboom and got it in Tue.

If I remember right, it ran fine when he had it.....i'd give the shotgun and peashooter a try....could be some smutz in the carb circuits that worked loose in shipping.

Lots of info on it in VMF Links.

 

[choctaw]

Yeah I'm sure I will get it worked out ,,,plan on shooting the shotgun tomarrow and checking my Vboost adjustment and a couple other things. It should open up at 6000 right ,,,well it doesn't about half the time or less it will but not untill 7500 or 8000. But back to work for now I will try some more tomarrow ,,,if anyone else has an idea let me know and thanx guys ,,,ride safe !!!