PSTERLINGJR Posted June 29, 2016 #1 Posted June 29, 2016 I just got a 1983 Yamaha Venture I was told it has carb problems. it will idle but just off idle it goes to **** back fires and shouts flames out of carbs. here is a link to a video of it. Also watch the tach it jumps all over the place. Thanks in advance.
Flyinfool Posted June 29, 2016 #2 Posted June 29, 2016 For starters. These bikes run like poo with the air cleaner off. But you have an electrical problem. The Tach is driven from the signal to the #2 coil, your tach keeps dropping to zero at the same time it runs worse. You are losing spark to one or more cylinders. I would start by cleaning the pins in all of the connectors to the coils and to the TCI (Ignition box). AND put the air box and air filter back on. While it is running look down into the carbs, all 4 slides should be dancing the same. if not then you also have some carb issues. But start with fixing the known problems first, the lack of spark and the missing air filter.
PSTERLINGJR Posted June 29, 2016 Author #3 Posted June 29, 2016 Thank you, yes the slides dance around the same, I will clean pins in the connectors and go from there.
VanRiver Posted June 29, 2016 #4 Posted June 29, 2016 Hi @PSTERLINGJR congrats on the new 83 venture!! I concur with Mr. @Flyinfool (as always since he really knows his stuff).....sounds like your bike is running on only 2 out of 4 cylinders when you give her gas. I had a similar problem on one of my 1986 Venture's when I first picked her up from the previous owner. She would appear to idle fine but had no power and my novice ears at the time didn't know the difference between a mighty Venture motor running on all 4 cylinders compared to 3 or 2. I would let her run for awhile and then test the temperature of each of the exhaust manifolds exiting the engine.....careful, as all 4 should be crazy hot and the same temperature on a properly running bike....if you find that 1 or 2 pipes are cooler then the others then those are the cylinders not firing properly and should be your focus. Long story short, my problem was a bad TCI module after I checked and cleaned all the connections. Those TCI modules are rather expensive to replace and almost impossible to test outside the bike (also a 1983 has a unique TCI compared to other Venture years too) so I strongly suggest you follow the process of cleaning all the connections as well as put fresh plugs in the bike as well before you diagnose it as a bad TCI. Here is a pic of what a TCI looks like just incase, since you might be learning all the do-dadds on your new fantastic motorcycle from Mother Yamaha.
bongobobny Posted June 30, 2016 #5 Posted June 30, 2016 Yup!! Dancing tach points to the TCI or connections. Could be water in TCI, which is a pain to get to. Unfortunately also, only '83 TCI's work on an '83, they are different from the '84 - '89...
NewbeeMC9 Posted June 30, 2016 #6 Posted June 30, 2016 How'd you know I need help:sign67: Anyhoos, congrats on the new scoot. Go ahead and join, the help is quite worth it. especially on the learning curve.
cowpuc Posted June 30, 2016 #7 Posted June 30, 2016 How'd you know I need help:sign67: Anyhoos, congrats on the new scoot. Go ahead and join, the help is quite worth it. especially on the learning curve. :guitarist 2: Hey JR, there are a number of these lop eared varmints who have had pretty good luck "cooking" the TCI.. What happens is, because of its mounting location it manages to get moisture in it which causes issues and a little time in an oven (not sure of temp but I guessing 100 degrees or so would be safe - do some digging or ask around a little and you will get some better thoughts on it) may take care of it. Another very common thing is to relocate the TCI up onto the air box where its dryer and/or does not get exposed to major temp changes like down in front of the carbs - better environment. All that said, if it were mine I would start with cleaning the terminal plug area really really good, as suggested, first thing though (easiest and hopefully it cures the problem) - just thought I would a little cause those REAL guru's keep stealing all the good answers and I like given em a hard time!!
bongobobny Posted June 30, 2016 #8 Posted June 30, 2016 We bake at 225 degrees because water boils at 212! Usually bake for an hour or so, ideally with the cover off!
PSTERLINGJR Posted June 30, 2016 Author #9 Posted June 30, 2016 Thank all of you for tips, I'm going to work on it tonight. I will post an update on what I find.
Condor Posted June 30, 2016 #10 Posted June 30, 2016 What it sounds like in the video is your running on 1 cylinder with the 2nd cutting in briefly. Change the plugs before doing anything else. If the problem persists with the air cleaner cover on, start at the top and work down through all the previous suggestions in this thread... and maybe a few still to come...
PSTERLINGJR Posted July 1, 2016 Author #11 Posted July 1, 2016 Well I took my TCI part last night found a burnt spot on it and a cracked board. So does anyone have a 1983 TCI box for sale.
ChurchBuilder Posted July 1, 2016 #12 Posted July 1, 2016 Post a picture. I'd like to see what a burned out to looks like. I have one but no idea if it's any good. Sent from my SCH-I545 using Tapatalk
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