bongobobny Posted July 11, 2014 Share #1 Posted July 11, 2014 Back in May the bike ran fine. It sat since then and now is misfiring and lacks Power. Pulled the plugs and found the left side all carbon'ed up and wet while the two right ones were fine. Put new plugs in it but it didn't fix it. Ran a heavy dose of sea foam through the tank and put around 100 miles but that didn't fix it. Filled the carbs up with seafoam and let it soak overnight, didn't help. Ran seafoam through each vacuum line, and then pulled the new plugs and they had the same as the old plugs, the left ones black and fouled, the right ones look like new. OK compression test and all cylinders good. Vacuum on all 4 carbs are equal. Today removed the plenums and sprayed a whole can of carb cleaner through the carbs. Still not fixed. I have a set of used coils to substitute out but the front left coil is near impossible to get to. I am now also suspecting the ignition module so I bought one off fleabay but it won't be here until next Friday. Tomorrow I am pulling the carbs to inspect and clean them and set the floats using the "Goose" method. I really don't think it is a carb problem as I have a hard time believing both on one side would go out at the same exact time. I am getting spark but who knows if it is happening at the right time on #1 and #2. Tomorrow I am also going to check the TPS for range of motion, the resistor element is in speck, I just don't have someone to twist the throttle while I hold the meter on the pins. I will also check the pickup coil but I doubt it is bad, the bike runs and #3 and #4 seem to fire fine. So I am really racking my brains trying to figure out what would cause 2 plugs to foul out simultaneously without the other two being affected... Link to comment Share on other sites More sharing options...
93 venture Posted July 11, 2014 Share #2 Posted July 11, 2014 Mouse nest in Air filter or intake system? Link to comment Share on other sites More sharing options...
djh3 Posted July 11, 2014 Share #3 Posted July 11, 2014 Did you OHM out the coils? Link to comment Share on other sites More sharing options...
bongobobny Posted July 11, 2014 Author Share #4 Posted July 11, 2014 Not yet, can't get to the left front. Once again though, 2 going bad at the exact same time??? It's on the adjenda... Link to comment Share on other sites More sharing options...
bongobobny Posted July 11, 2014 Author Share #5 Posted July 11, 2014 Mouse nest in Air filter or intake system?No, but did find as leaf! Put Brand new K&N's today. At first I suspected a bad left air filter but then found out they are interconnected... Link to comment Share on other sites More sharing options...
Neil86 Posted July 11, 2014 Share #6 Posted July 11, 2014 Before tearing apart carbs....remove tank and inspect the bowl vents for the left side carbs....they share the same vent hose, right carbs share another. It can do wierd things if pinched shut, hose end facing into airstream etc... Link to comment Share on other sites More sharing options...
bongobobny Posted July 11, 2014 Author Share #7 Posted July 11, 2014 Thanks Neil!!! I WILL look there first!! A quick blast of air should clear any obstructions. Dion, I just figured out, I can test the coil primaries from the igniter connector!! Link to comment Share on other sites More sharing options...
BradT Posted July 11, 2014 Share #8 Posted July 11, 2014 Hey Bob once it gets fixed don't let it sit so long.....Got more than 4k miles since mid May. I would be looking at the ignition circuit. Not exactly sure where but that is where I would go next. Good luck Hope you get it going soon. Brad Link to comment Share on other sites More sharing options...
Carbon_One Posted July 11, 2014 Share #9 Posted July 11, 2014 Good luck Bob. My 09 had both rear coils go out last year when I first got it ready for the road after having it triked. Whether both went out at the same time or not I have no idea but once they were replaced the bike ran fine. And still does today at a year and a half later. Ma Yamaha questioned two going out together but eventually replaced them under warranty. Anyhow hope you find a simple & cheap fix. Larry Link to comment Share on other sites More sharing options...
saddlebum Posted July 11, 2014 Share #10 Posted July 11, 2014 Hey Bob before you pull everything apart put an inline spark tester between the plug and boot. Make sure it is the adjustable type were you can widen the gap. You should be able to open the gap to almost 5/8 of an inch and see a spark jump. Easy way to test your ignition system. Also If you use a setup like I posted earlier for wet checking the float levels you will be able to see if the float and needle/seat is functioning properly. With this bench set up you will able to see if a carb is flooding. http://venturerider.org/forum/showthread.php?t=86821 You can leave the carbs assembled initially and fore go the clear tube for now. Just supply the pressurized gas to each carb one at a time to see if it overflows and starts coming out of the vent tube. Link to comment Share on other sites More sharing options...
Money Venture Posted July 11, 2014 Share #11 Posted July 11, 2014 Setting the gap to 5/8ths of an inch on a high tension lead that is connected to a spark plug under compression and running is a good way to ruin a coil. If it has to jump that big of a gap, it can find an alternative gap like across the windings creating a carbon track that will me nearly impossible to find but always there causing grief. Link to comment Share on other sites More sharing options...
bongobobny Posted July 11, 2014 Author Share #12 Posted July 11, 2014 I am going over to Auto Zone this AM and buying an adjustable ignition spark tester that goes to ground to measure the spark. Actually, according to the Yamaha service manual using an inline the minimum acceptable gap is 0.031" so added to the 0.035" plug gap I should get to 0.066" without losing spark... Link to comment Share on other sites More sharing options...
bongobobny Posted July 11, 2014 Author Share #13 Posted July 11, 2014 Before tearing apart carbs....remove tank and inspect the bowl vents for the left side carbs....they share the same vent hose, right carbs share another. It can do wierd things if pinched shut, hose end facing into airstream etc...DING DING DING!!! We may have a winner!!!!! Tested the spark, good to around 0.070. pulled vent hose and tried blowing through it, clogged! Pulled the hose out and found a big chunk of something at the end. Not sure if it fixed it as the air cleaners and plenum are off the bike but it seems better. Still want to set floats anyway but may not as curiosity is getting the better of me... Link to comment Share on other sites More sharing options...
ragtop69gs Posted July 11, 2014 Share #14 Posted July 11, 2014 Get that puppy running Bob, we got some roads to burn up next weekend :thumbup: Sent from my SAMSUNG-SGH-I997 using Tapatalk 2 Link to comment Share on other sites More sharing options...
bongobobny Posted July 11, 2014 Author Share #15 Posted July 11, 2014 Yah Jay, who'd a thunk it?!!? As long as the weather holds up... Link to comment Share on other sites More sharing options...
bongobobny Posted July 11, 2014 Author Share #16 Posted July 11, 2014 Yup, just went for a ride and it's running like brand new!!! Many thanks Neil!!!!! Link to comment Share on other sites More sharing options...
ragtop69gs Posted July 11, 2014 Share #17 Posted July 11, 2014 Yah Jay, who'd a thunk it?!!? As long as the weather holds up... Link to comment Share on other sites More sharing options...
ragtop69gs Posted July 11, 2014 Share #18 Posted July 11, 2014 Before tearing apart carbs....remove tank and inspect the bowl vents for the left side carbs....they share the same vent hose, right carbs share another. It can do wierd things if pinched shut, hose end facing into airstream etc... Link to comment Share on other sites More sharing options...
Phoneman1981 Posted July 12, 2014 Share #19 Posted July 12, 2014 Interesting read. Ride Bob ride! Link to comment Share on other sites More sharing options...
bongobobny Posted July 12, 2014 Author Share #20 Posted July 12, 2014 You betcha Mark!!! Link to comment Share on other sites More sharing options...
saddlebum Posted July 13, 2014 Share #21 Posted July 13, 2014 (edited) Setting the gap to 5/8ths of an inch on a high tension lead that is connected to a spark plug under compression and running is a good way to ruin a coil. If it has to jump that big of a gap, it can find an alternative gap like across the windings creating a carbon track that will me nearly impossible to find but always there causing grief. This is why you use an adjustable one. You start with a small gap and gradually you widen the gap until the engine starts to miss fire. Min gap is generally about 1/4 with plug in line but I have opened the gap up as high as 5/8 of an inch before starting to get a miss fire. Have done this for many years, on all types of ignition systems, without an issue. Bear in mind your only doing this until the cylinder starts to miss fire and only for a couple seconds max. Leaving it in that state too long does run the risk of coil damage or other ignition damage. I Do Apologize though, I should have been a little more clear about the procedure in my initial post. Sometimes you forget that although most on this site Like Bobby are mechanically inclined, there are a few who are not, but do read these posts to learn something and there fore better clarification is always a good thing, for those trying to understand what it is we put in these posts. And Finally Glad to hear you are up and running Bobby. Edited July 13, 2014 by saddlebum Link to comment Share on other sites More sharing options...
bongobobny Posted July 13, 2014 Author Share #22 Posted July 13, 2014 Yah! Put on a very enjoyable 100 miles yeterday and it's running fine, ready for the trip to Michigan next weekend! Link to comment Share on other sites More sharing options...
Neil86 Posted July 13, 2014 Share #23 Posted July 13, 2014 good to hear! Link to comment Share on other sites More sharing options...
JerryK Posted July 14, 2014 Share #24 Posted July 14, 2014 I think it just needed a good long ride and not set so long between rides....I hope it's OK but you sure did a lot for a simple problem! Link to comment Share on other sites More sharing options...
bongobobny Posted July 14, 2014 Author Share #25 Posted July 14, 2014 Well, actually what happened is some insect decided to build a nest in the float vent hose for #1 and #2 carburetors. What happens is as the fuel pump fills the area, positive air pressure fills up the float cavity preventing the needle valve from closing off. The fuel pump is continuously pressurizing the cavity so where does the gas go?? through the ventura and into the upper cylinder area so that when the valve opens the combustion chamber gets waaay more gas than the required ideal 14/1 ratio, resulting in a less than ideal ratio which will not ignite as well if at all. This results in an extremely rich mixture which leaves the spark plugs with a black deposit and wet. I consider it amazing that the bike even ran on 2 cylinders much less was capable of speeds close to 60 mph... Link to comment Share on other sites More sharing options...
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