Triumphrat

dawgfan · 06-22-2006

This has just recently started happening and I just had the carbs tuned...

Say I am coming to a stop from 3rd gear. I will brake, engine brake, downshift and so on until I roll so slow I can put my feet down. At the "feet down" moment I am occasionally getting a "hiccup" like the bike missed a breath or something. It kinda sounds like the bike would cut off if I did not give it some immediate gas. This also happens at idle while say, waiting for a light to change.

It is not terrible and does not happen every time. I need to get out and really get the bike warm to ensure that it does it after a really good warmup. I don't think it is a warmup thing and I swear I remember it happening with a fully warmed-up engine.

Just curious if this rings a bell with anyone.

[ This message was edited by: dawgfan on 2006-06-22 14:14 ]

DWIT100 · 06-22-2006

I've had the exact same thing happen after riding for a while and then pull up to light. Bike definitely warmed up and not cold - has happened after I was on the road for 50 miles etc. Never has quit running, just a hiccup.

mecscc · 06-22-2006

Sorry for your troubles. Can we narrow things down a bit?

Was there some reason you had the carbs tuned? And what is involved in "tuning" the carbs in your case? And, more importantly did it do it before they were tuned?

I'm trying to isolate whether it is a carb problem or electrical or fuel flow problem, which is why I ask. If the ONLY thing that is different is the carb tuning, then that is most likely the culprit. Something got messed up in the carb, or got in the carb, that wasn't there before.

Oh, yeah, your last tank of gas: did you get the same gas at the same place?

Monte

Another thing I forgot to ask: after the tuning is the bike idling noticably slower? If you have a tach is it idling, when warm, below about 1200 rpm?

[ This message was edited by: mecscc on 2006-06-22 19:57 ]

dawgfan · 06-22-2006

Quote:

On 2006-06-22 19:54, mecscc wrote:
Sorry for your troubles. Can we narrow things down a bit?

Was there some reason you had the carbs tuned? And what is involved in "tuning" the carbs in your case? And, more importantly did it do it before they were tuned?

I'm trying to isolate whether it is a carb problem or electrical or fuel flow problem, which is why I ask. If the ONLY thing that is different is the carb tuning, then that is most likely the culprit. Something got messed up in the carb, or got in the carb, that wasn't there before.

Oh, yeah, your last tank of gas: did you get the same gas at the same place?

Monte

Another thing I forgot to ask: after the tuning is the bike idling noticably slower? If you have a tach is it idling, when warm, below about 1200 rpm?

* I got the carbes tuned/balanced cause I saw some extra blueing on one pipe PLUS I was not exactly sure how much my old shop (which got sold) did with the bike. It was one of those "just make sure" visits.

* I am not sure if it has done this prior to the recent work. The bike runs really well now, except for these occasional hiccups.

* When I got the bike, they had idled it down quite a bit. I am not sure if I had it too high or what but I have bumped it up a tad from what they are doing. I do not have a tach but have ridden for years and know the sound of a good "bouncy" idle. I would not know if it is idling below 1,200. I was shocked the other day at how high I can rev this bike and not hit the limiter. I think the D&Ds make you think you are closer to the limiter than actual.

* Re: the last tank of gas. I can not get that gas anymore as it is almost two hours from Atlanta and not far from TN border. I went 130 miles before reserve. I must admit that I am realizing that while I might not ride that hard, I do "go through the gears" much more often in the city. You guys were probably right.

Thank you for the help.

The hiccup is not bad, it is just weird. It is like when your bike cuts off on you at a light and it is just a bit embarrassing...but it does not quite cut off, it just hiccups once.

If it continues to do it, I am taking it to the shop since they JUST worked on it and getting it checked.

[ This message was edited by: dawgfan on 2006-06-22 20:24 ]

mecscc · 06-22-2006

OK. That helps a lot. Let's assume that the guys at the shop didn't screw up the carbs (I'll come back to that later) but DID screw with the idle. Unlike the advice you may have heard from the TA/SM guys with 270 degree ignition, you have a 360 degree twin, firing with a wasted spark sequence, and you do not really want a "bouncy" idle. You might like the sound, but the bounce is really a small one of those hiccups! So, your idle is probably set quite a bit lower than it was before you took it to the shop.

Try this. Get the bike good and warm, at least a ten mile run, come home, let it idle and turn the idle down to where it stumbles, not hiccups, but stumbles. Then turn it the other way until it seems to be running a bit too fast. Repeat until you get it to the spot where it never stumbles. Then, INCREASE the idle a bit more- until you think it might be just slightly too fast. If you had a tach you would find you are at about 1200 rpm. With a slightly fast idle your bike will be much more responsive on take off, will not stumble, or hiccup, and will not give you heartburn thinking it might quit.

If that works, fine; problem solved.

If not, then before I'd look for something electrical I would suspect that in the process of working on your carbs the shop boys stirred up some gunk (scientific term) in the float bowls, or, if they took the carbs off they might have disturbed some of the junk in the bottom of the tank or in the gas line.

If you promise not to laugh I'll tell you how to solve that one yourself, without having to touch anything. Go to an auto supply and buy a bottle of MMO (Marvel Mystery Oil). Following the directions on the bottle mix the right ratio of MMO to gas into the next three tanks of gas. Be precise, or err on the side of more rather than less. Too little won't do any good.

It isn't really as snake oil as it sounds. Racers have used it for years. I've used it when I raced and in my street bikes for over 50 years, not all the time, but when small junk plugged up the fuel system, or when the bike didn't run as smoothly as it had. MMO is the best solvent on the market, will not hurt your bike, and will disolve any small particles of hydrocarbon in your system, even paint chips!, and then you burn them up and send them out the exhaust. There are other much more expensive solvents on the market, like Techron, but they are basically MMO in a small bottle with a big price tag.

I hope the first thing works. If not, try the second. And if that fails take it back to the shop and tell them that they screwed up your bike and you want them to make it right.

Good luck,

Monte

dawgfan · 06-22-2006

Mecscc,
I think you are on with the first one, the idle comments. When I got the bike set (idle) how I liked it, it was a tad more idle than what would seem normal but the bike always seemed to "like" it.

After getting the bike back from the shop, I made the assumption that they knew better than me and had done full warmup idle adjustments and that it should be that much lower. SInce then, I have bumped it up but not as much as I would normally.

The best way to describe it is that when I had it set to a slightly higher idle the "bounciness" had better rhythm. With the idle set a bit lower, the bounciness is a bit more irregular.

I am going to go back to how I had/like it with a slightly higher idle and see how that works.

On the MMO, wow, can you really run that stuff in your gas? If it comes to that I will do that next but I think you pegged it in that I have been trying to get used to the shop-set lower idle and that may be the culprit.

oh i forgot.. Thank You.

[ This message was edited by: dawgfan on 2006-06-22 22:56 ]

amanger · 06-23-2006

dawgfan,

I d say that they ve set your low speed mixture screws ( pilot screws) too rich.That will only show up when the bike is warm not when its cold.Try backing them off 1/4- 1/2 a turn.

Andrew

Woops. Yep your right wind them in 1/4 - 1/2 a turn.
Thanks Eagle. :???:

[ This message was edited by: amanger on 2006-06-23 02:30 ]

eagle · 06-23-2006

If you back them off - won't that make it run richer - not leaner? I thought you needed to screw them IN to get a leaner mixture.

Fossil · 06-23-2006

I'm guessing that your hic-up is caused by the idle set to low.Turn it up a bit and see if it stops . I keep mine at 1200 rpm .

dawgfan · 06-23-2006

Quote:

On 2006-06-23 02:12, amanger wrote:
dawgfan,

I d say that they ve set your low speed mixture screws ( pilot screws) too rich.That will only show up when the bike is warm not when its cold.Try backing them off 1/4- 1/2 a turn.

Andrew

Woops. Yep your right wind them in 1/4 - 1/2 a turn.
Thanks Eagle. :???:

Where are the pilot screws? I may try this when the bike is warm if the idle adjustment does not solve it. The shop is not close.