The Saga Continues

[Wizard765]

This is a bit long but I'm getting frustrated so I'm hoping someone can find a solution for me..

 

It started with a solo run (wife not with me) and having some fun with Marcarl. Got to going a "little" faster than usual and noticed the bike would not go over 5'000 rpm.

It also developed a miss after that so I changed the plugs and it seemed somewhat better.

A short time later (maybe 2 tanks of gas) I was on my way to Bongobobny's and it started missing again so changed the plugs at his place and all is good again.. but one of them was black..

Started thinking I might have a bad coil..

Changed the coils from a friends parts bike.

 

Then it didn't fix it so I dug down into the frame again and took out the TCI. I have a friend that is awesome with a soldering iron so I took it to him and we took it apart. Once apart it was obvious that there was a problem. All 8 of the diodes were just a pile of dust. I'm actually surprised it ran as well as it did.

 

We changed all the diodes and buttoned it up.

 

I re-installed the TCI and started the bike. It seemed to run fine so I put it all back together.

 

Then once it was back together started it again and it ran fine for a couple of minutes then ran like crap and lost the tach. Seemed to be running on 2 cylinders.

 

Took it all apart again and got a couple of TCIs from Ray that he had laying around.

 

Again it seemed to run fine so I started to re-assemble only this time when I got one side done I tried it again.. back to running like crap and no tach.

 

So what I'm thinking is that the transistors are gone or going. Seems to run fine when dead cold and soon as the electronics warm up it quits,

Got ANOTHER TCI from Bongobobny and it came out of a good running machine but may have been on the shelf for awhile.

 

Numbers are slightly different My original was a 41R-10 and the newer one from Bob is a 41R-11. I'm thinking this should be alright but it's still a problem.

 

Now the bike will idle fine and rev up fine without a load. Will run for as long as I want without quiting BUT once in gear there is no power and it kicks and sputters..

 

Any ideas??? help? I'm getting real tired of taking this thing apart so many times..

 

I am ordering a new TCI from Dingy but I just got back from vacation and he is being kind enough to wait until I get a cheque or two in..

[93 venture]

Have you thought about trying the pick up coils, I have seen them work ok when cold and not when they get hot, also check all the connections at the tci for being tight and clean, Check for power and ground at the tci, I use a head light to load test it, head lamp will draw 3 to 4 amps and test the wires where a test light or volt ohm meter has almost no amp draw.

[Trader]

you've changed enough TCI's that I would have thought you eliminated that problem.

 

 

You've changed plugs....so I would think maybe coils or plug wires?

(not that I really know what I'm talking about....but it seems you've already covered the TCI issue)

 

and not to add to your burden...but did you see my PM of a few days ago?

[93 venture]

I was looking at the schematic and it also looks like if your loosing the tack you will also loose the fuel pump relay. the green and yellow wire comes from #2 coil to the fuel pump relay and to the tach. Could be why your are run ok until you put it under a load, no fuel psi:confused24:

[Flyinfool]

Also you mentioned that one plug was black, this could indicate a carb issue where one or more cylinders are running rich. What did the rest of the plugs look like? What did the plugs look like the second time you changed them?

Maybe a stuck float????

 

But then on the other hand, since the tach is dropping to zero that indicates an electrical issue.

 

Maybe you have more than one unrelated issue going on at the same time?

[bongobobny]

OK Wayne, here's another suggestion. Temporarily short out all 3 pins on the kickstand switch connector. Keep in mind that now the bike will start IN GEAR WITH THE CLUTCH OUT!!! Now with all caution see if the problem goes away. I have seen those switches develop just a wee amount of contact resistance and cause a similar problem, but usually causes the engine to die in gear when the clutch is let out.

 

If that checks out OK next thing to look at is the kill switch. It too may have some contact resistance but I'm not sure the symptoms would be the same as yours.

 

Third, and a very distinct problem is your vacuum pressure sensor could be bad! You can bench test this with a battery, voltmeter, and vacuum pump. as you apply vacuum the voltage should change on the output to the TCI. There is a detailed procedure in the service manual as to how to test this.

 

Now,as far as the -10 and -11 it is the difference between the TCI for a 1200 and 1300 motor. The only difference is a slight variation in the advance curve for vacuum advance but is so insignificant you will never notice it except for maybe 0.001 sec difference in your ET on a quarter mile...

[Evan]

Good luck In finding and fixing your problem Wayne. While I won't even pretend to be able to help you, I am reminded of a problem that I had many years ago with my KZ 650. It took over a year to finally find the problem after going to several shops. None of their mechanics could figure out the problem. Turned out that one of my coils that tested good was breaking down under certain load conditions.

[greg_in_london]

I'd check what 93 Venture said. It seemed to be a common fault 10-15 years ago but I hear of it less often now. The explanation was that the wire was too short in the resin block and, while it was okay when cool, the expansion eventually breaks the contact and disconnects when it gets hot. I don't know if that was true or not, but I suddenly went onto two cylinders when the engine was warm 12 years ago and then found that the length of time that it would run properly after starting from cold became shorter and shorter. Replacing the pickups solved it. It sounds a little like your problem, but I thought it only applied to 83 models.

[pmelah]

check your side stand relay as well just pull it and try to crank and put under a load just one item to check