Idle problem (video)
 

I figure if you guys on here can't figure it out then nobody can lol:D

This a clip of my 98 VTR acting up. It seems to have an issue with smooth idling. the bike cuts out sporadically as if it wants to stall out. I have noticed it happen very rarely while riding in the lower RPM's, it may in fact be happening more often but perhaps it just might be going unnoticed because of the engine speed or inertia etc. Any help in diagnosing the situation would be greatly appreciated. Sometimes it does it as frewuently as this video shows and then other times not at all...Once in a while it sounds like there is a large backfire or something thru the airbox because it can be felt thru the tank, but this is much more rare then the rest of the events. Thanks for looking. !

http://www.youtube.com/watch?v=87o1_wEd07E

Mine does the same thing and when I rev at low RPMs the front carb pops bad when cold.

It sounds ignition related but it is rather hard to tell. What really got my attention was how hot the bike is running.

Mine almost never gets to the half way point on the gauge and when it does the fan kicks on and drops it below the half way point.

So my question would be was the fan running while you filmed this?
Also does it only happen when the bike is hot like that or does it happen all the time?

Yeah, I have only hit the second mark on my dial in mid summer, through stop and go traffic and on track... Other than that it stays around first mark...

I'd say either a jetting problem with lean/hot and popping, but not neccesarily by jetting, could be something else contributing... Or like 841hawk said, ignition...

What are the history on the bike... Stock? re-jetted? Unknown?

Have you checked the obvious things... Airfilter, plugs and general condition on hoses and such... Did the problem just appear out of the blue, or did you to anything, no matter how insignificant when it appeared?

8541hawk, I was riding the bike around stop and go traffic style in first gear in the neighborhood and also letting it sit for some time and idle, the fan was on as I recall. From what I recall it tends to happen regardless of the temps but I will try and keep an eye on it. I had the bike stall out completely several times in the past but i just attributed it to vtwin nature and idle/misfire etc when I had my idle set at about 1000, since then I turned it up to 1200-1300 so that it won't die on me when it does this.

tweety, from what I recall the bike is stock (I purchased it from chickenstrip a few months ago) . I have not checked the filter, plugs hosesetc yet, I did check the ground wire, battery terminals, the ignition coil mounts (only the one mounted in the tail), I dont have much free time so I'm not sure when I will be able to get a thorough look at the bike. I was hoping that it was a common vtr related thing and there would be a quick answer. I appreciate the help though!

I recall it happening in the past but perhaps with not as much frequency, and the times that it did happen it would stall the bike because the idle was lower around 1000. I have been trying some wheelies this past weekend in a parking lot but nothing out of the ordinary happened there. I'm not very good at doing them and only had 1 hardish landing and even that was probably from only 1.5feet (50cm) height....

is it possible that its a short somewhere? on friday it did stall out on me and I recall it not cranking over when I hit the start button.... but the problem is that I also have a battery that may be on it's way out...

Seeing as you know nothing about the condition of the bike, I'd start with the basics... Have a look at the airfilter and see if it's in good condition or needs replacing... While you are in there lift the bottom of the airbox and check that the two carb breather hoses have been moved from the stock (Read stupid!) position...

Before you do though, take the time to download the service manual (it's linked in a thread in the forum, stickied)...

It's a bit of a crappy situation, I'm living here temporarily while im in school and don't have any of the tools with me.... I guess I will see how much can be done.

You can do that with the toolbox under the seat if neccesary, and if you have it...

My bike was doing the same, I think it's electrical since it has pretty much gone after putting a brand new battery in.

Check electrical connections, it appears to be a full electrical miss. Start with battery, starter solenoid, ground wire, and voltage R/R. $20 gets you a DMM, not that it would have the resolution to pick up a voltage spike.

Any luck?

Thanks for checking back Gord, I haven't had the opportunity to do anything more yet. I'm waiting for a multimeter inthe mail and then I will weight my alternatives and what direction I should go with this..

so this is where I am at so far.

I got my multimeter in the mail today, the battery tests at 12.54V, It was pretty dark so all I could do so far is a current leakage test as per the manual (thanks tweety) and it comes up 450uV which is more then the specified 0.1mV maximum, tomorrow I will test to see if it's the RR

...well I decided to go back out there even with the lighting situation lol... turns out that disconnecting the RR still yields the same current leak. so the 2 alternatives are a faulty ignition switch or a short somewhere in the harness. i'm hoping for the ignition switch but the harness seems more likely. If it were the harness it may also explain the idle situation, perhaps there is a momentary grounding out killing the ignition to the engine. seeing as how the idle situation is sporadic it could be the vibrations randomly causing contact between the shorted wires (I had similar situation with the RC51 some years ago, twins love to shake themselves to death I guess....) but this is just theorizing at this point. With my RC51 it turned out to be 2 different and unrelated electrical issues at once which was fun to solve...

any suggestions on where I should start as far as trying to track down the situation on the harness or the ignition? the manual says to disconnect things one at a time and keep checking performing the leakage test. I was thinking of starting the hunt near the components involved with ignition, or I recall from a post someone else had that they were experiencing a current leak to the instrument cluster....

I checked the harness by unplugging connectors and the 450uA remained until I disconnected the 6P for the instrument cluster, the Bl/Br and the Br wires were the ones drawing the current.

I didn't have the time to check for any missing/false continuities in the harness.

So there is a current leak but I have yet to find out if there is short anywhere.

The battery is weaker then 12.54 (which I originally posted), once the ignition is swithced on it reads 11.5V or something like that. I think the battery is getting drained by the current leak and the idle problem is something different (yet to be determined)

Well... That kind of makes a suspiction of mine stronger... Fading battery, low resting voltage that drops lower with load... Wierd ignition problems... Most likely caused by the dropping voltage...

You wouldn't by chance still have the stock R/R? If you do, stop looking for the symptoms and fix the cause... It's friggin 12+ years old, what do you expect?

BTW If you manage to hit the lottery and find the one R/R that survived 12 years, replacing it now before it fails in a week to a months time isn't going to inconvinience you noticably... Most likely it will save you money too...

no it has an aftermarket RR (tourmaster if I recall correctly).

so you think that the weak battery on its own could be the problem causing the idle issue? That still leaves a current leak of 0.5mV compared to the 0.1mV maximum recommended by the manual, any thoughts? if I do replace the batt with a new one then do I not risk draining that one aswell if the leak is 0.5 vs 0.1 maximum? or is this difference negligable?

A battery tender could solve your problems. On sale at Cycle Gear for about 20 bucks right now.

Well... A 0.1 mV drain takes 5 times as long to drain the battery as a 0.5 mV drain... Other than that there really isn't a difference... The difference is usually made up for in raised resistance due to corrosion... Find and an eliminate that and the voltage will drop, most likely not all the way to 0.1 mV at this point, but closer...

A healthy battery has a resting voltage above or very close to 13V when fully charged, and a fully healthy R/R will keep it there... Check the R/R's performance... I'm willing to bet it's not up to spec... An aftermarket R/R is most likely still a diode based one, ie waiting to fail... And usually they last shorter than OEM... A mosfet one lasts basically infinitely and performs better...

So yeah, swapping the R/R doesn't end the problem, but like I said... Cause and symptoms... I know what end I prefer starting at... You make your choiches...

Sorry to disagree, but no it wouldn't... It's a band-aid on a broken bone... It doesn't fix what is wrong, it just keeps the electric system going until it's completely broken... And then fixing it has become more difficult...

reducing the corroision is a good suggestion, I will give that a try when I have the gauges off next. I'm assuming dielectric grease will help as well so i'll pick some up.

would it be possible to swap the analog gauges for the later model digital gauges ? a quick look at the wiring diagram shows similar wires with the exception of the side stand light.

I will look at the RR tomorrow

I came across this and it sounds helpful

http://www.triumphrat.net/speed-trip...r-upgrade.html

Nothing harder to fix than an intermittant or ghost problem.

Some day you young ones will learn........ ;)

but I'm with Tweety on this and believe he should focus on the R\R and replace it with whichever type makes him happy but replace and and all should be good.

There are a lot of threads on this forum with similar info...

My advice, get the harness from www.easternbeaver.com and a R/R from eBay and then go over the harness, find the corrosion, check all ground points and clean and seal them with dielectric grease... If that doean't cure the problem, well... Then you get to have fun finding anything non-electric that can be wrong... But honestly, I'm 99% sure once all that is done, you will be fine as far as the wiring... Only other thing would be the coils...

I have a battery on the way, just ordered.

Tested the RR, stator, stator output when running and charging voltage with the bike running everything was within spec

btw the RR is a TourMax not tourmaster as I originally posted.

What is "according to spec" and whose spec's? Honda's specs are about as good as their wiring and R/R's, ballpark right, but you can do better...

Also, did you test the conductivity of the diode's in the R/R? ie if it's discharging when the bike isn't running... Pretty common problem, and causes a lot of "hidden" problems...

i did both the service manual and what is outlined here http://www.triumphrat.net/speed-trip...r-upgrade.html

I checked for continuity between the yellow and the ground and there was nothing. is this what you mean by conductivity of the diodes?

No, not continuity... If your multimeter has a diode test use that between the three stator leads of the R/R (unplug R/R first)... If not measure resistance... No resistance or low resistance is a problem... A very high resistance is what you want, and you want it to be absolutely the same for all combinations... If not... Well... New R/R...

Sorry that's what I mean, diode tested and the readings came back working