Triumphrat

luckyduck · 11-02-2012, 05:42 PM

Quote:

Originally Posted by bluesforchallah

What it is that just dawn on me was I never actually pulled the plastic spacer between the needle and needle spring under the diaphragm after I was thru screwing with the needles. I've heard that it's possible for one of the 4 legs of that spacer to block the bleed orifice at the bottom of the piston causing what would also seem like symptoms of a misfire. I've already ordered my pick up coil and replacement gasket, but I think I'll have a look into the tops of my carbs when I get home tonight only to rule this out as a possibility.

Correct me if I'm wrong, but I don't think there is any "pulling" being done with the needle holder. All the instructions I've looked at just state to drop the holder in after the needle and make sure it's not blocking the hole.

Haynes says this:

section 3A-10: "9. Fit the needle into the piston, then fit the needle holder, making sure it locates correctly and does not block the air hole in the piston."

Now I didn't know how to interpret that really. I just dropped the needle holder in and didn't bother to press it in. It wasn't clear how the holder should "locate" correctly as there were not any indents or detents to locate it.

So what's the word on this fellas?

Ten Thrty2 · 11-02-2012, 08:51 PM

im doubting its a carb related issue, reason being is its happening to both my cylinders at the exact same time, what are the odds I have the same issues in both carbs making their appearance at the same time. I could be way off but that line of thinking has convinced me its not a vac. leak or a jetting issue

please correct me if I am wrong, just trying to narrow down my trouble shooting before I tear this bike apart!

roadie · 11-03-2012, 09:53 AM

I;ve had this problem for a while. At first it would stall every once in a while at idle. This was with the regular stage 1 upgrades on my 2007 Thrux. Over the course of a year I replaced ignitor with Procom, TPUSA 904, 813 cams, new pick up and ignition coils, plugs, new battery(s), regulator rectifier, FCR carbs and sundry other upgrades and a couple of dyno sessions. Over the course of this it would still intermittently cough/cut at idle although not out right stall (feels like it wants to though). Tried lots of carb adjustments and vac leak checks/rubber replacements to no avail. Bike runs amazing except for this and the fact that it happens so intermittently is tough to fix. At this point I have no idea.

Srxy · 11-03-2012, 10:36 AM

This sounds exactly like the symptoms I had when I had an air intake leak on my Buell. The increased air flow causes it to run lean and the revs go up on idle. When you're pushing it you get to a point where it leans out and coughs on you. I would do the carb spray test or propane test. If the bike idle changes when you spray the carb cleaner around the air intake boots then one if them (or both since they're the same age) could be leaking. Ditto for the vacuum plugs.

Sheepdog · 11-03-2012, 12:15 PM

You may wish to pull your float bowls and look for some sediment. Ethanol fuels can form aluminum oxides there and cause intermittant obstructions; especially in the idle circuit. Clean the float bowls and run some fuel injector cleaner in your fuel (Seafoam or Techron), it can smooth your engine's performance considerably.

Ten Thrty2 · 11-03-2012, 01:45 PM

if its a problem of it running lean, how much damage would I do by making the idle mix a little rich and see if the problem goes away??

RedRocker · 11-03-2012, 02:36 PM

Same bike ('07 with same upgrades) here. I only get this issue a few times a week it seems... haven't stopped riding though, since it's my only way to work. Going to look for leaks now; I don't want to risk running lean.

prior · 11-03-2012, 03:05 PM

You need to be using WD40 for hunting airleaks rather than carb cleaner. Give the boots a good drenching to see if engine note changes, then try it again on the exhaust side.

Luckyduck- your symptoms sound like fuel flooding. O-Rings on pilot screws can perish causing the bowls to flood, causing the hard start, lagging throttle etc.

Ten Thrty2- do you need to use the choke on start up and if so for how long? High idle would suggest running lean so maybe your jets aren't the right size/matched correctly with the filters. It would tie in with the coughing and near stalling- fuel starvation. Also don't discount the valve clearances being out, this can also cause this type of running.

Also what condition are your plugs in? This will be a good indicator what is happening to the fuel mix.

luckyduck · 11-03-2012, 11:17 PM

Why WD40 and not Carb cleaner?

Quote:

Originally Posted by prior

You need to be using WD40 for hunting airleaks rather than carb cleaner. Give the boots a good drenching to see if engine note changes, then try it again on the exhaust side.

Luckyduck- your symptoms sound like fuel flooding. O-Rings on pilot screws can perish causing the bowls to flood, causing the hard start, lagging throttle etc.

Ten Thrty2- do you need to use the choke on start up and if so for how long? High idle would suggest running lean so maybe your jets aren't the right size/matched correctly with the filters. It would tie in with the coughing and near stalling- fuel starvation. Also don't discount the valve clearances being out, this can also cause this type of running.

Also what condition are your plugs in? This will be a good indicator what is happening to the fuel mix.

prior · 11-04-2012, 02:31 AM

Quote:

Originally Posted by luckyduck

Why WD40 and not Carb cleaner?

Carb or brake cleaner is pretty aggressive stuff and can damage rubber components and your paintwork. I've heard that people also use aerosol starter fluid too which is supposed to be a bit safer.

Unlike the above which changes the AF mix by sucking in gas through the leak, WD40 will seal the leak temporarily as well as providing a propellant. I used it to chase a leak on my old CB250N and it works well.

However if you want to be a pro- run an unlit propane torch over the area to do the same job as brake cleaner with no mess or damage. Just dont forget to put your fag out before you do.