Dynojet startup

[Anonymous]

Okay you are all probably tired of people and they're Dynojet problems but here's mine anyway. I just installed a dynojet stage 3 with K&N air pods and it won't start. The bike ran before the dynojet. I put in new o rings in the carb and manifold boots. #15 pilot, #138 main. needle is 2nd notch down. I have dyna ignition and the timing is correct and the valves are adjusted. I ran down the battery once trying to start it, recharged the battery and ran it down again this time with the assistance of starting fluid. It fired a couple of times but never ran on its own. The temperature here is about 40 degrees. The air screw are 1 1/2 turns out and the fuel screw on the bottom are 3/4 past their originall setting. What should I do or check now?

 

[KEITH KRAUSE]

OK. I'm assuming you primed the carbs and can see fuel and spark.
Did you cap the #3 vacuum nipple (if a Pingel valve)? Are the manifold vacuum adapter screws tight and copper washers on? Did you adjust the idle adjuster knob several turns in to allow the bike to start? Are the floats set close to .94"?
If all this is good, the most common reason for your problem is a poor carb synch or no carb synch before initial start up. The VM carbs must at least have the slides synched by eye (both fully closed and fully open throttle positions) as part of the jetting process. This eye synch still needs to be followed by a vacuum tool synch.
I should also suggest the "base settings" for the jet needle are usually too lean on your model. If you have a quality 4-1 pipe, I bet the jet needle e-clip should be in the 4th position from the top (no jetting spacer), or possibly with the jetting spacer on top the clip (still in the 4th position) if the 4th with no spacer is too rich.
Remember, the VM carbs MUST be re-synched every time you disturb or adjust the needles or throttle shaft.

 

[Anonymous]

No I did not prime the carbs, how do you do that? I did check for spark but how do you know that you are getting fuel? the floats are set. You say no jet washer and and needle set 4th from the top? Not what the instructions say but I'll take your word on it. I will increase the idle speed a little and check the carb synch. thanks Keith.

 

[pano]

The petcock usually has a "prime" position where the fuel flows freely without the bike running. If you put it in prime and wait a couple minutes the bowls will fill up. Once started it will run in the prime position but you should put it in the run position. if you forget to put the petcock in the run position you risk fuel from overfilling the carbs and having the fuel go places you don't want.

 

[KEITH KRAUSE]

If you have the stock petcock, turn the lever to "prime". Wait a minute. If it starts, turn the lever to "on" after 10 seconds or so.
If you remove a sparkplug, there should be fuel on the plug after cranking the motor.
Synch the slides by eye. Be sure the little "nick" on the slide (looking at engine side) are all uniform as possible. The fully open slide position must also be done next. The slides should be adjusted so their bottom is between .5mm and 1mm above the top of the main bore with the throttle held fully open. Lift the throttle pulley by hand and look up through the FILTER SIDE of the carb throat to see the bottom of the slides and adjust the throttle pulley stopper screw until the adjustment is correct. The throttle pulley stopper screw is mounted with a spring. You should see it when it contacts the pulley.

 

[Anonymous]

I'm not getting any fuel into the carbs. I have the equivelent of a pingle valve, it's just in line. Looks like the stock one broke and a previous owner put this inline valve in. I know I'm getting fuel through the valve but thats about it. The float bowls are dry. Tomorrow I'll take the float bowls off if I have to. Could there be air trapped not letting the fuel in?

 

[KEITH KRAUSE]

I'm not getting any fuel into the carbs. I have the equivelent of a pingle valve, it's just in line. Looks like the stock one broke and a previous owner put this inline valve in. I know I'm getting fuel through the valve but thats about it. The float bowls are dry. Tomorrow I'll take the float bowls off if I have to. Could there be air trapped not letting the fuel in?

Well, I question the flow rate of this in line valve you mention, but if you can see fuel exit this valve and the bowls are dry, then you have a blockage somewhere or ? No, trapped air is not the cause.
First, if you're not using the vacuum from carb #3 to open a stock petcock, you should cap it off tightly. I'm assuming the stock petcock is set to prime.
Next, are you sure the 5/16" fuel line is connected to the "T" fitting between carbs 2 and 3?
If the fuel line is connected right, then you have a blockage in the carb fuel passages to the bowls, or the float needle valves are varnished and stuck closed against their seats. These are the only ways you would have NO fuel at all in the bowls.
I'm guessing you didn't clean the carbs? Clean them out well and use compressed air if you can. Verify the passages are clean by inspecting and blowing through them and feeling/listening for air exiting each valve seat hole, etc.
Remember to remove the two floatbowl vent lines and leave the brass nipples open.

 

[Anonymous]

The fuel line is connected between carbs 2&3 and the carbs are really clean, it appears that the carbs were rebuilt recently... new gaskts etc. I removed the float bowls and as soon as the float dropped far enough fuel came out so the floats must not be adjusted right. I have a question about the floats. There is a flat recess on them, does that go up or down? When I took them apart they were down and thats where I took my measurement for setting the float. Is this correct? I could have sworn on the GS 750 I used to have the flat spots were up and that would also alllow the other tang (not the one that goes against the needle) to prevent the floats from dropping to far.

 

[Anonymous]

WE HAVE IGNITION!! I went ahead and turned the floats over so that the flat recess is up and then I re adjusted the floats. I opened the float drain and let fuel run out for about 30 seconds just to make sure the float bowls were filling up. Turned the key on and it fired right up! So now I guess I need to adjust the air screws and synch the carbs with my new Pro Motion synch tool and then take her for a spin. Any other suggestions would be appretiated.

 

[KEITH KRAUSE]

Just got in. I didn't know floats could be adjusted to the point that no fuel would enter. At least SOME should have entered, even if adjusted wrong.
When the floats are installed correctly, there is a tang that contacts the tower, so the floats will not drop completely and allow the float valve to fall out. You can also always see the shiny wear mark on the adjusting tab where it contacts the float valve's spring tip. Your description of your floats and what happened has me a bit confused, but if the fuel is now flowing, I'll leave it at that.
You do have to adjust the floats anywhere from .90" to .98". I set mine at .94" This measurement is from the bowl body (no bowl gasket) to the highest part of the float. You should also check both sides of each float to be sure they're straight. They're often tweaked.
Yes, you should adjust the side air screws for the highest idle and then reset the idle to 1,100 rpm's with the idle adjuster knob. After adjusting each screw, turn the idle back to 1,100. After all four are done, synch the carbs. After the synch, I always re-check the side air screws for highest idle again. They usually end up about 1 1/2 to 1 3/4 turns out. I use two large fans to cool the motor during the synch. I set mine at 2,500 to 3,000 rpm's. Always adjust the highest mercury level(s) to come down to the lower levels you initially see. It's VERY important to get the levels so the difference between the highest and lowest level is about 1/2" if you can, or closer. Anything beyond 3/4" will give you mixture problems. Too high a level will cause that cylinder to run richer than the lower adjusted levels. Too low, will cause lean problems. If you get condensation in your lines, you can very quickly pull the line off and replace it quickly while the bike is running. You'll see the level drop quickly and jump back up as you replace the line, hopefully with the water out. Don't let the throttle return quickly, or you may suck in mercury. DO NOT over-tighten the adjuster screws and their locking nuts. 3.5 ft/lb is good.
Good luck and let me know how it goes. I'll try to check in with you tomorrow.

 

[KEITH KRAUSE]

I was thinking about what may have happened with your floats, and the only explanation is they were installed upside down.
I've never tried it to see how the floats would fit, but if they were put in upside down, they would be sticking up so high that when you placed the floatbowl over them, it would push them down and force the valve needle to close hard. That's why no fuel at all came through. Hopefully this didn't weaken the small valve springs inside.
Anyway, I'm off to work. Let me know what happens.

 

[Anonymous]

Yeah, the floats were in upside down and as soon as I took the bowl off they dropped far enough to let the needle fall out because there was no tang to prevent the float from dropping all the way. There was some fuel in the bowl but very, very little.. not even enough to come out of the drain plug. I'm off to sych the carbs now. I'll let you know how it goes.

 

[Anonymous]

Okay, I got the carbs synched. That was pretty easy. I'm glad I have that tool now, no more guessing. They were off quite a bit and it really smoothed it out. It doesn't really want to idle below 1300-1400rpm though. I adjusted the air misture the best I could but any lower idle speed is too slow and it wants to die. Should I attempt to adjust the fuel mixture on the bottom? Do you do that the same as the air screws...highest idle? I haven't looked at the plugs yet and I haven't taken her for a ride yet. It's raining and it might snow this weekend. Of course Monday is supposed to be sunny.

 

[KEITH KRAUSE]

OK. The synch went well but it won't run below 1,300 rpm's. I'll have to assume your tach is reasonably accurate. If you've been around similar bikes, does it SOUND like 1,300 rpm's before it begins to stall?
Where are your pilot fuel screws set at now? If between 1 1/4 and 1 3/4 turns out, the stalling should not be because of their settings.
I'm wondering about the float height adjustments. You previously said they were set, but later it turned out the floats were upside down. This means they were not set correctly. If the fuel levels were too low, the motor should run worse as you open the throttle or as the rpm's rise. Since the stalling happens at nearly closed throttle/lower rpm's, I'm thinking the fuel levels are too high and it's gagging for air. Your bike should easily hold an 1,100 rpm idle.

 

[Anonymous]

I took it for a test ride today and the power is flat, it flutters. I pulled the plugs and the insulator was still brown at the top but there was black soot at the bottom and around the outside. Number 2 plug was wet with fuel. Maybe I accidentally have the clip in the 3rd notch instead of the 4th. Or mabey the fuel jet is off on that one. I'll check the needle position first. Should I move the clip to the 5th notch or install the jet washers? Those go on top of the fiber washer that is already on top of the clip? Also the choke (fuel enricheners) don't have as big of an effect as they used to. Probably because it's too rich already?

 

[KEITH KRAUSE]

I took it for a test ride today and the power is flat, it flutters. I pulled the plugs and the insulator was still brown at the top but there was black soot at the bottom and around the outside. Number 2 plug was wet with fuel. Maybe I accidentally have the clip in the 3rd notch instead of the 4th. Or mabey the fuel jet is off on that one. I'll check the needle position first. Should I move the clip to the 5th notch or install the jet washers? Those go on top of the fiber washer that is already on top of the clip? Also the choke (fuel enricheners) don't have as big of an effect as they used to. Probably because it's too rich already?

Hi. I'm not sure what "flutter" means. A wet plug could be several things. I'll do my best to help you, but I would ask you to do things that I would if I was there or it was my bike. This would mean testing at higher speeds that is easy where I live, but could be unsafe where you live. I have some questions first.
Are you sure the electrical system is right? Timing, good spark, newer plugs correctly gapped, etc?
Are the valve clearances reasonably correct. This has a big effect on the carb synch and therefore the mixtures.
Are the carbs for SURE clean and are the various o-rings inside them in good condition? You replaced the manifold o-rings, correct?
You have a 5/16" fuel line, the vacuum nipple is capped at carb #3, the gas cap venting is clear, and the two floatbowl vent lines are removed and the vent nipples are open?
You retained the two jet needle plastic spacers, the thicker one ABOVE the e-clip, and the thinner one BELOW the e-clip, when swapping to the DJ needles, correct? (The DJ jetting spacer always goes on top the e-clip, if needed.)
Have you correctly re-adjusted the floats close to .94/95"? Did you check both sides of each float to be sure they're not tweaked?
Are the pilot screws (underneath) about 1 1/4 to 1 1/2 turns out? Are the side air screws set for highest rpm?
You said the vacuum synch went well. So the levels are very close to each other. At what rpm did you set them at?
All jets are tightened firmly?
The exhaust header gaskets are in good shape?
Jetting can be difficult, so I have to ask you all this stuff so I can get an idea. ALL THE ABOVE is important. Any short cuts to cleaning, adjusting, not replacing worn parts, etc, will just cause frustration and a waste of time. Let me know what's been done and I'll tell you how to test and get your bike running right.
I would possibly try your e-clips in the 4th position from the top WITH the jetting spacer on top the e-clip. This means a new vacuum synch must be done. But FIRST answer my questions and tell me again how it's running.

 

[Anonymous]

I don't know how to explain how the power feels I just know it isn't right, it's not crisp. As far as the electrical system goes it probably all needs to be replaced. With the voltage regulator bypassed it only charges at 12v. The plugs are in good condition and the timing and valve adj. is correct. I'm posative the carbs are in good condition. I put in ALL new O rings, ordered from Robert Barr. The header doesn't leak. The floats are set at 23mm with the gasket on both sides of the float. I have 5/16 line and the vent lines are removed. The vacuum line is plugged.
I didn't know the gas cap had a vent, I'll take a closer look at that. Only one plug is wet so I possibly did something wrong on that one. The thick spacers are on top of the clip and the thin is below. Thats how it was when I took it apart. If I put the thin one on top that will make it even richer right? I synched the carbs at about 1500rpm and they were all within 1/2inch of each other. I set the air mixture screws to the highest idle and i will have to recheck the pilot screws underneath. I put the clip in the 4th position from the top.

 

[KEITH KRAUSE]

First of all, let me correct myself. The thicker spacer, actually called a "ring" goes on top the e-clip. The thinner spacer, actually called a "plate", goes below the e-clip. I've given the correct order several times in past posts, but I made a mistake this time. Just a simple mistake, but it would cause more problems. Sorry. I'm sure that helps you to trust me. :lol: I'll go back and edit that.
I'm concerned about your spark. Is it fairly blue and fat? If the spark is weak, the plugs reads/performance will seem like rich jetting. If one cylinder is not burning fuel well, your performance would be as you describe. If you're sure carb # 2 is set up just like the others, and the others cylinders are OK, then it's either a weak spark or low compression that's leaving unburned fuel on the plug. Have you tried another plug in #2? Have you tried swapping #2 and #3 leads to see if the problem follows? Can you take a compression test? Did the bike's plugs do this before the re-jetting? Any blue or whitish smoke from the exhaust?
Something is making #2 run richer or not combusting well. It's possible that your pilot screw could be the cause. If you try turning it in about 1/2 turn, this may help. These screws are not always uniform after re-jetting. But generally, if you have to turn any pilot screw beyond 3/4 of a turn beyond what others are set at to get good results, then this is a sign that you're compensating for another problem. This adjustment would only effect lower speed plug reads. You could have a choke plunger not completely sealing, but that would generally cause only low speed problems too.
My point is, you can't re-jet if one cylinder is suspect or running differently from the others.
Have you tried any higher speed tests with plug reads? Does the wet plug stay wet at all throttle positions?
Jetting is all about throttle position.

 

[Anonymous]

Well, I already changed the spacers but I moved the clip too. The carbs are not back on the bike yet so it's not that big of a deal. I moved the clip to the #2 notch and put the big spacer underneath and the small on top. This would make it a hair leaner. does it really matter which one is on top as long as it accomplishes the same goal. Like I said I moved the clip from #4 to #2 from the top. It made it so that just a little less of the top of the needle was showing, which would push the needle down more, making it a little leaner. The plugs were all a good color of tan before. Possibly the #2 wire wasn't making a good connection and not firing at all causing the wet plug and flat power? I'll try again tomorrow. Thanks and happy new year!

 

[KEITH KRAUSE]

I'm sorry about the spacer thing. I realize you may be putting a lot of faith in whatever I type, so a simple mistake like that makes more work. It's not easy to stay close to the computer and stop something before it happens. I tried.
As far as I'm concerned, the two spacers MUST go in the correct order. To swap them in the wrong order would just add confusion. I'm sure there's a mechanical reason Suzuki makes them in two thicknesses. I would put them back right. I also think the e-clip in position 2 from the top will be too lean. At least that's been my experience with several 1000's. Whatever you do, the carbs have to be re-synched after any needle changes.
You said the plugs porcelain was a tan color, which is good. And some darker soot around the top of the threads is typical too. But your performance "sounds" on the rich side. Usually that plug color means a good running motor. So I'm scratching my head a little. I'm still worried about the wet cylinder being the real reason, not major jetting changes.
We have to find out why that cylinder is not burning fuel like the others.
I would check the plug lead for any cracking and for clean/solid connections at the coil and plug cap and verify that the spark is as good as the others.
I have to get out to my in-laws house now. I'll try to check in with you tomorrow. Happy New Year!