Run on choke

[Frank1lee]

Hey guys, so i picked up an cheap 04 kat for a thousand dollars, had a few things I messed around with it. But for some reason, it doesnt run right unless it has the choke about halfway on, regardless of how warm the engine is. I had my mechanic run through the carbs and replace all the gaskets, and I've tried running it without a air filter. It doesnt seem to have any power whatsoever, I feel like Im riding around a scooter. Any suggestions?

[arsenic]

Find a new mechanic.

[Purplehaze]

Arsenic's got this covered, seriously you need to find a new mechanic or do your fair share of reading to learn about your machine and fix your machine proper.

Check your jetting, or have a mechanic do it for you if that's your thing. Ensure it's a stock or otherwise PROPERLY setup kit.

[Kreylyn]

Hey guys, so i picked up an cheap 04 kat for a thousand dollars, had a few things I messed around with it. But for some reason, it doesnt run right unless it has the choke about halfway on, regardless of how warm the engine is. I had my mechanic run through the carbs and replace all the gaskets, and I've tried running it without a air filter. It doesnt seem to have any power whatsoever, I feel like Im riding around a scooter. Any suggestions?

Find a new mechanic.

Arsenic's got this covered, seriously you need to find a new mechanic or do your fair share of reading to learn about your machine and fix your machine proper.

Check your jetting, or have a mechanic do it for you if that's your thing. Ensure it's a stock or otherwise PROPERLY setup kit.

They are right, your mechanic sucks.


The reason the bike does not run right is because the pilot circuit in the carbs is dirty or not set up right. Additionally there could and probably are other issues too. "Choke" adds fuel through the fuel enrichment system. So by pulling the lever to make it run your adding fuel. This simply shows us that your pilot circuit that is supposed to be supplying fuel at idle is not giving enough.


It's something you can fix by simple research... this website has all the info and directions.


Krey

[arsenic]

These don't need choke to run:
carburetors carbs Suzuki GSX600F Katana 600 98-06
Just saying...
You're avatar photo is not an 04 Katana BTW, is that the bike in question?

[Frank1lee]

So take a look at the pilot jets? I've replaced one main jet, I havent even though to look at those.
I've also considered the new fuel filter I put on might be blocking some of the intake, I'll work on that tomorrow.

These don't need choke to run:
carburetors carbs Suzuki GSX600F Katana 600 98-06
Just saying...
You're avatar photo is not an 04 Katana BTW, is that the bike in question?

No, I also own a 94 kat, I wrecked it being an idiot. Got spooked by a loud truck and hit my rear brake in a turn. Thought it would be cheaper just to buy a new bike.

[arsenic]

Not just the pilot jets, but yeah, the pilot CIRCUIT is clogged. Cleaning the pilot jets is a good first step. See if that fixes it.

[mykat]

If you say you have no power, it's not just the pilot circuit. Pilot circuit only affects idle through 1/4 throttle. While the gas tank is off, you might as well pull your plugs and have a look at them.

Chances are you're running rich/lean. It's possible you're running on 3 cylinders as well, which could be a simple spark issue, wires can come unseated from their boots. Quick test is to let your bike warm up to running temperature, get a damp rag, turn the bike off, and touch the rag to each header. If it doesn't sizzle, that plug isn't firing.

Edit: I'm not sure if post kats have the same style spark plug boot. For pre kats you screw the wire into the boot, and if its poorly seated, you'll see evidence of arcing if you remove the wire and take a look.

[arsenic]

you could say the pilot circuit only effects low RPM, but you'd be wrong, The pilots circuits primary function is idle, but it effects everything.

[Purplehaze]

Indeed, even though idle is where it affects it most the Pilot Circuit is always open and flowing. Main jets are just to supplement more air moving through (more throttle). If this isn't understood I'd recommending reading up on CV Carbs. Understanding the theory is important to understanding your bike.

Not a bad idea to test and see if your running on all four, use a spray bottle instead, though. Should have results from spraying a bit of water after just a few seconds of running. As I said though, make sure you check your jetting for wear, or that whatever is inside is properly setup if not stock. This can lead to poor power.

Not holding an idle points to (as Arsenic pointed out, surprise surprise) the pilot circuit or extremely-out-of-sync, assuming you're running on all 4.

[mykat]

Not a bad idea to test and see if your running on all four, use a spray bottle instead, though. Should have results from spraying a bit of water after just a few seconds of running.

And if you don't have wet rags or a spray bottle, you can always piss on the headers in a bind.

you could say the pilot circuit only effects low RPM, but you'd be wrong, The pilots circuits primary function is idle, but it effects everything.

If you compare the orifice sizes of the 32.5 pilot and pilot air jets to that of the main jet and emulsion tube, it just seems like the amount of fuel/air flowing through the pilot circuit after 1/4 throttle is completely negligible. Probably 10-100 times less fluid flow, which seems hardly enough to noticeably affect the a/f ratio.

Am I missing something?

[arsenic]

yeah

[Purplehaze]

which seems hardly enough to noticeably affect the a/f ratio.

Am I missing something?

Welcome to Mikuni CV Carbs. They're the Achilles Heel of the Katanas. There's a reason Mechanics 101 is the *most* viewed sub-forum. There's a reason *most* threads are regarding, or are concluded as 'Carb Issues'.

[crazycraven420]

and secondary to your carb issues...what air filter are you using?