Starting Problem/Blowing out the carb

[randy]

Back-puffing is a symptom of carbs being out of sync, that's all. I did not write that it is the cause of all of your troubles!

[Peter]

Carb

Okay thanks I hope I can get the thing to idle enough for me to use my carb syn tool.

[TopCatGr58]

Hey Peter,

I merged your threads, because you're still dealing with the same bike and similar problems, not starting and then not running right! It helps us to help you to keep the information in the SAME THREAD so that we can follow what has been done, suggested, etc.!

Adjusting the cam tensioner properly can also keep the valve timing tighter, which can help reduce the back blow thru the carbs cause it will help close the intake valve sooner before the piston is rising to create compression.

As Randy stated, a lean running carb will quite often backfire thru the carb!

You state 2-3 have good spark, via new accel coils and tested against engine. IF 2-3 are still cold, then the carbs are not right, either massive vacuum leak not allowing them to suck in the required fuel/air to burn. Have you checked the intake boots, the synch ports of the boots to ensure no leaks??

Also you can swap the spark plugs....not the wires.... from 1-4 to 2-3 to see if the problem follows plugs. IF 2-3 get hot and 1-4 cold, then possibly simple as fouled plugs. IF 1-4 still hot and 2-3 cold, then CARBS, vacuum, etc.!
T.C.

[Peter]

Okay well the other two wires in that plug (starter relay) after jumping them the neutral light comes on which is good. I did some checks on my TCI unit and everything is good except the white/red wire is dead to ground which it should have 12 volts, which when followed goes to one of the pick up coils. WHich would probaly explain why the two cylinders are dead. And how the spark is super weak for excell coils. So iam on the search for a TCI unit, my bike apparently doesn't require ballast resistor...should I try to wire one in??

Tka all
Peter.

[TopCatGr58]

Hey Peter,

The TCI's rarely die. What usually can happen is that the solder joints to the pins can crack, break, etc.! Randy(elect. Guru) has stated to take the top cover off of the TCI and resweat all of the solder joints!

Regrettably, the 81 TCI's are a bit more rare and $$ since they were only made for 1 year. They have internal programming for the Cent. Adv. Curve, hence why you only have the Vac. Adv. mechanism under the timing cover!

Another option is to get the mech. cent. adv. parts, not sure if the 81 Vac. adv. parts will work with the earlier parts? And then you can pick up one of the older more plentiful 78-80 2H7 TCI's, or even make your own....see tech tips!!

Hope resweating them helps, otherwise happy shopping!
T.C.

[TopCatGr58]

Followup message!

Hey Peter,

After sleeping on things, I realized that I hadn't inquired as to WHAT type of Accel coils did you put on?? IF you put on the ones with the 1.5 ohm resistance, then YES you could have possibly fried the output transistors by drawing too much current thru them, not enough resistance load? But if you have the 3.0 ohm res. coils, then it's back to checking and resweating the solder joints as a first step! Well, maybe second step, first OHM check the coils themselves, even new ones can go bad!!

As for putting a ballast resistor in line, again, only needed IF you have the 1.5 ohm coils vs. the 3 ohm coils! HTH!?
T.C.

[randy]

BTW,

The coils that need the ballast are marked with the words "uses ballast resistor".

[TopCatGr58]

Have another cup of coffee there Randy!

Yep, for the OEM's but is this the same for the ACCEL's?
That's what he has said he put on!
T.C.

[Peter]

The coils I bought are these ones http://www.accel-motorcycle.com/Prod...Search=140403. I ordered a TCI from ebay so I should get it in about 1-4 weeks time. I really need one now that I broke the one I had..:-( IT's funny how weak the actuale spark some of the plugs, There was like 1 or 2 plugs when cranked over damned near knocked me over but the other plugs had very very little spark. Which again is probably why it had dead cylinders. And again how that white/red wire only had like 0 volts compared to 12 which I need, to go to the coil. To unleash beasts power....:-)

[TopCatGr58]

Hey Peter,

Yes, those are the correct coils with the correct 3 ohms resistance, no need for a ballast resistor! However, I still say, what do you have to loose, take the TCI cover off, don't try to take it OUT of the case, and resolder the contacts, you might get pleasantly surprised. Then if it does work, then you will have a SPARE, good to have, I've got one since I also have the 81 4RO TCI!!

Randy can repair the 2H7 series, but the 4RO's he's stated that he can't because of the porgrammed chip innards! Hope you got a good price!
T.C.

[Peter]

Good I bought the right coils.......but I did try to take it out of the case......and well I guess you can figure out what happened...crack!! Oh well......it's only money, I bought one off of ebay for 40 bones...good deal! So needless to say my TCI has ended up in my blue box for pick up. Where can I post pics of my bike here??

TKs

[randy]

Peter, do not throw the TCI away. Ship it to me, I'll pay for the shipping.

Randy Rago
15-03 132nd street
College Point, NY 11356

[Peter]

Okay sure no problem, I'll see how much it will cost and I will let you know as soon as I can.

Peter.