Triumphrat

elDizzle · 04-16-2007

Just did Predator exhaust, AI elim, and AIRBOX removal (145 Mains 42 Pilots, 2.5 turns out). I'm idling at about 1500 rpms...shouldn't I be around 1000? :???: How do I fix this?

Tia!

piecesenregalia · 04-16-2007

Turn down the idle adjustment (little black knob under the carbs on the left side).

elDizzle · 04-16-2007

Thanks! On a similar note: how long is it before a bike is considered "warmed up"? I was told from the dealership to always use the choke on most days and only until you hear bike idle up to 2000 rpm, then turn push choke back. I hear leaving in on any longer will damage engine? I understand that our bikes are air cooled, so we shouldn't let our bikes sit at idle for very long anyways, right?

piecesenregalia · 04-16-2007

The "choke" is just an enrichment circuit in the carbs. Before the bike is up to operating temp., the fuel doesn't atomize as well. The choke just adds a little fuel to compensate. It's not going to damage your engine. The damage would be from overheating, like if you leave it idling and go get a sandwich or mow your grass. Use the choke till it idles good without it (assuming it idles good).

elDizzle · 05-13-2007

Got my bike to idle closer to 1100 rpms. I think someone tole my anywhere from 800 - 110 is okay. BUT, with my current carb tunig state, I get a "pop" coming from the underneath my seat. It's not from my exhaust (like a backfire). This only happens to me when I'm idling at a light or something, never under throttle. I think I'm running way too rich? My buddy who rode behind me said he could pretty taste the gas every time I got on the throttle.

What's the proper way to tune the mixture screws? And is this related to the "pop" under my seat? The jets were recommended when i bought the exhaust, etc.

TIA!

TonyThruxton · 05-13-2007

I get that 'pop' exactly as you describe too, but only twice at two long red lights. I actually felt something 'pop' on my leg from my left side cover. I wondered what it was too. Bike seems to be running fine and pods ok.

I have Predators, and airbox removed. Dealer did the jetting.

Anyone have any ideas?

Thanks as well,

Tony

TCL · 05-13-2007

The bike makes numerous odd popping noises when it is running lean, or even when it is running perfect on occassion. I'd try turning your idle screws out to 3 turns and see if that helps.

As far as the warm up goes, if I have time and the neighbors are all awake, I start the bike with the choke all the way out. Let it run about 15 secs, it revs about 1500-1800 and then I push it in halfway. Idle will go down to around 750rpms. Sit on the bike, put my helmet on, gloves on, sunglasses on, back out of the garage. Then I push the chock in all the way. The bike is still running at about 900rpms when I pull away, but it is not stalling out at the stop sign down the street. I go easy on the throttle for the first mile or so and then she is usually pretty much warmed up to 1100rpms.

So basically, I let it warm up about 2 mins in my garage and then warm it up on the ride. I allow more time in the winter. I think it's ok to warm the bike up by driving it, as long as you don't give it too much stress before the oil thoroughly coats all the parts.

Remember, you don't want to give it any throttle when the choke is out. The choke richens the gas and will gum up your spark plugs quickly if you make a habit of leaving it out and blipping the throttle.

badrufus · 05-14-2007

According to the Jenks Tuning Guide, an 865 Thrux with open exhausts and airbox removed should be 140 main jets, 40 pilot jets, 1 shim on each needle, 2.5 turns out on the idle mixture screws. Check here:
Jenks Tuning Guide
You can download and print the whole thing as pdf by clicking on the link.
On a warm day, I pull my choke out, start the bike, let it warm for about 30 seconds, push the choke in to half choke, and take off within a minute or two. Within one to two miles, I push the choke in to off. It doesn't have to be fully warmed up to reduce the choke; you just want it to be able to take some throttle so it doesn't stumble. For the first few minutes, I will be careful when taking off from a stop, feathering the clutch and giving it some gas so it doesn't stumble and die. On a really hot day, I will usually start with only half choke. Every bike is different, but I would be hesitant to let the bike idle long enough to build up to 2000 rpm when the engine is cold.
When is it fully warmed up? Different ideas on that. I usually take it easy for the first 10-20 minutes of riding, but that doesn't mean that's how long you need to leave the choke on.
You're right about not wanting the bike to sit for long at idle.

elDizzle · 05-15-2007

Dumb question: on the idle mixture screws, # of turns out is counterclockwise? (If righty is tighty, left = turns out?) :???:

Thrux-ton-up · 05-15-2007

Quote:

On 2007-05-15 01:12, elDizzle wrote:
Dumb question: on the idle mixture screws, # of turns out is counterclockwise? (If righty is tighty, left = turns out?) :???:

Turn the screw clockwise and lightly seat them to a stop them turn them counterclockwise the number of turns desired - follow Jenks tuning guide - its good stuff.