Onboard Computer Issues

[JTJones]

I recently purchased an 83 Yamaha Venture 1200. There were some minor issues to take care before riding, such as the slave cylinder was frozen, and the carbs were completely dirty. This bike sat for about a year, indoors.

 

So my pops and I pulled the carbs off the bike and soaked each one for 24 hours in 2 different cleaners. We reassembled the carbs and reinstalled them back onto the bike. At first, I was getting a bit of popping and cracking coming up through the carbs into the air filter compartment. After riding it for a day or 2 and blowing out the carbs, the popping and cracking settled to just every once in awhile. So that part is taken care of for now.

 

Another issue I am having is the onbaord computer is acting funny. The fuel guage goes up and down and sometimes shows empty with a full tank. The oil light comes on throwing a warning, and even the temperature guage is throwing a warning. All of this is intermintent and comes and goes. I know it has to be a wiring issues. However ... we did not mess with any of the wiring during our work on the carbs. All we did was unplug the battery cables at the battery terminals.

 

Does anyone know what could be causing this malfunction of the onboard computer, to make it act goofy and throw warnings. Like I said ... it only does it every once in awhile.

 

I would appreciate any real advise on this issue.

 

Thanks

JTJones

[sarges46]

http://venturerider.org/forum/showthread.php?t=33328

 

There are other great post in support of the 1st gens. The resoldering of the computer boards is one of the easiest to do just be careful.

 

I now own a 2nd gen but did these fixes with my 1st gens and they worked great.

[JTJones]

What do you mean? Why would I resolder the PC?

[paysaw]

The tem PC Board means "Printed Circuit Board".The CMS unit or the " Comuter Monitor System" is the the display on the bike that tells you about the main systems .There are help files on how to take one out and do the service and repair.I have am 83 VR with all the classic problems.These help files are great and easy to follow.If you dont get it,make a post and someone will jump in and help you.!!!

[bkuhr]

My first guess for intermittant as described on multiple systems, is charging system. Although I have had CMS problems on 83 VR repaired with resolder, Your problems sound very simular to problems I had on 82 XJ750. After replacing volt-reg,++, finally found problem to be shorted winding on stator. The XJ CMS would intermittanly start a reboot sequence, and kept I killing batteries, although showed 13-14v charging. Finally installed amp meter to ride with, and proved shorted winding was drawing more current than other windings were producing, with a net result of battery discharge. After replacing stator all problems fixed.

PS. 83 VR known for CMS problems due to broke/cold solder joints on PCB. Usually with headlamp ckt. You may have multiple problems.

Suggest start with stator winding Ohm check, and there IS a difference between .4ohms=good and .2ohms I had and thought good enough-not.

PPS. Lot of info on this site for your bike, search under 'first generation' Every procedure I suggest listed in detail.