85 RPM Tach running crappy on 0

[dlucian]

This is going into my third season of having the bike. Didn't need to do very much to it thus far, just the usual, oil, plugs etc. I parked it at the end of last season with her running fine. I pulled her out a few weeks ago when we had a nice weekend here in Indiana and I wasn't able to ride. She ran like garbage thought it was just water in take, poored some heet and all that. Let the bike idle for a little, and once she started getting warm (just past black line when first heating up on guage) she starts spitting and sputtering and RPMs go down to 0. If you try to ride, (again, thinking it was water and trying to blow it out) she'll spit and sputter randomly. I can feel all 4 hitting, then it drops off back fire etc. I put it away cuz weather went too cold again. I pulled her back out this week because weather is good again, and tried to ride with my borther around town to kill some gas and get it threw. Once it warmed up again (same spot, ish) I was coasting to a stop sign and she died. Fired back up no issues, but idled so low that it did it again, if I didn't keep reving it she died. On take off, I had to pull up RPMs to get it to slug to move. Pulled over at the local mall to let her cool down, and she was ok. I could limp her back home again type of thing.. I'm at a loss, I've changed the plugs, made sure the wires were fine, but...???

 

Also, on a side note. I don't know if it's related or not, but just to be on the safe side. I'm also starting to have electrical issues last season. The dash back lights, don't work. I've hit a few bumps or hit the high beam and they pop on, but once I kill the bike and restart they don't' work again. The radio is alos having issues, if I use the knob to turn it off all the way and then back on (Never tried immediately after doing it, not that I recall usually the next day etc.) the radio take a while to turn back on..?

 

Thanks for any advice to where to look, I've tried to search the web, and this site and wasn't able to find any info..

[snyper316]

I am no expert but it sounds like you need to clean up some electrical connections. Clean connectors at TCI and all connectors you can get to. spend the $12.00 on the site because it is a wealth of knowledge. If after all that read up on first gen tech read only thread. I believe it says something like TCI trouble Yes or No and TCI testing Info.

[Flyinfool]

If the tach drops to zero with the engine running bad that is the first clue.

The tach is driven from the #2 cyl primary side of the coil.

So if the tach drops to zero then the #2 coil is not getting a signal to fire.

That means you have electrical gremlins.

All of the other issues sure points to a bad ground. It is possible that all of your issues could be a bad ground. I would start there.

[dlucian]

Thanks for the replys, I thought it might be a bad ground, I'll have to tear into it when I've got more time. My dad talked to my bike mechanic that I normally take it to and he told me to drain the float bowls, if they're full of water it'll cause the tach to read zero so I'm going to start there and move on. I do plan on getting a membership down the road, but atm I'm unemployed that's why I was trying to get the bike up because I'm in school and spend $20 a day to drive to school lol (150 miles round trip, a day, m-f but almost done 3-1-17 is last day, thankfully)

[snyper316]

Thanks for the replys, I thought it might be a bad ground, I'll have to tear into it when I've got more time. My dad talked to my bike mechanic that I normally take it to and he told me to drain the float bowls, if they're full of water it'll cause the tach to read zero so I'm going to start there and move on. I do plan on getting a membership down the road, but atm I'm unemployed that's why I was trying to get the bike up because I'm in school and spend $20 a day to drive to school lol (150 miles round trip, a day, m-f but almost done 3-1-17 is last day, thankfully)

 

Sorry to say but that mechanic does not know a thing, The tach reads off of the number 2 coil there is no wires running to your carburetor, as a matter of fact no tachs run off of the carbs!! It is more then likely a bad ground or dirty connections, if none of that after you have cleaned them up run the test thats in the tech forums. But if I was you I would not take this bike back to that shop just my opinion.

[Yammer Dan]

Time to get a new Mechanic!! Cleaning TCI connections could help or moving TCI to top and drying out. Info is in Tech Library.

[Flyinfool]

Well I suppose that if all the float bowls were full of water the tach would read zero because the bike would not run at all..................

 

So in the most technical sense the mechanics statement is true, but it is not at all relevant to your issue. His statement sounds more like a line of BS because he has no clue what the issue really is and he is trying to find out if you have a clue so that he can run up the bill with more BS.

 

Then there is also the possibility that something got lost in the 3rd hand description of the problem.

[bongobobny]

Yup, your mechanic is a DF! The tach is fed by electrical pulses from the TCI output to the number 2 coil...

[dlucian]

appreciate the info, I'll look into it probably this weekend. As far as the mechanic goes, he's never steered me wrong in the past, and we're all human all make mistakes.

[dlucian]

ok, got it apart and looking at coils, but can't figure out which is #2 ..help please?

[Flyinfool]

#2 is the one with the grey wire going to it.

[dlucian]

Got it figured out, front right wasn't firing. Fired her up and ran her for a min to warm them up to figure it out. Pulled plug wire and replaced it, working fine again. thanks for all the help. Still not 100% (gas) but that'll be fixed tomorrow when I run her out.