t500 question about idle weirdness

Need some help? Put your question up here. Many years of experience on the board to help you get up and running.

Moderators: oldjapanesebikes, H2RICK, diamondj, Suzsmokeyallan

Post Reply
Sharky
On the street
Posts: 33
Joined: Wed Aug 10, 2016 1:38 pm
Country: United States
Suzuki 2-Strokes: 71 T500 Titan

t500 question about idle weirdness

Post by Sharky »

So, I have rolled this around in my head and made what changes I thought would cure the symptoms enough, and I wanted to see if anyone on here had any ideas.

T500 with pipes and pods. Electronic ignition. I have ran the gambit with jetting and I have ended up with this problem. It is hard starting, usually taking 10-15 kicks with the choke on (won't start without choke, though it will when warm). This is with the 30 pilot jet. 32.5 and 35 just made starting near impossible.Once it starts, it wants to hang at 3000 rpm and I have to blip it to lower idle back down to where it is set around 1200. It lowers the idle slowly, and did this with the larger 32.5 pilot jet as well. I am saying this because I thought everything pointed to a lean idle curcuit, but now I don't know, because it doesn't seem to be solving it with any adjustments to the mixture.

I rebuilt the engine as best I could, but could only change the outer 2 seals on the crank, and am hoping that it isn't that one of those seals is leaking by and causing a lean condition. But like I said. I am banging my head at this point and am open to opinions/suggestions.

Thanks for any help.
Craig380
Expert racer
Posts: 1250
Joined: Mon Dec 01, 2008 2:52 am
Location: Manchester, UK

Re: t500 question about idle weirdness

Post by Craig380 »

What fuel tap are you using? A vacuum tap or a conventional on/off gravity tap?

I don't mean to tell your granny how to suck eggs, but if it's a vacuum tap, ALWAYS turn it to 'prime' when starting from cold. A quirk of Suzi strokers is that if you leave the bike more than a couple of days between rides, the floatbowls sometimes will not fill enough on the fuel tap's normal (vacuum-controlled) setting. This might help reduce the number of kicks to get 'er going.

Every Suzi I've had needs to be started from stone cold like this:
- fuel tap on prime
- choke on full
- don't even LOOK at the throttle
- kick 3x with ignition OFF
- ignition ON, kick once
- after it's fired, juggle choke to keep rpms at 1,500 - 1,750 for 10 seconds
- ride off gently (I hate to leave the bike idling when cold, better to get riding and knock the choke off quick)
1976 GT380 - wounded by me, and sold on
2006 SV650S - killed by a patch of diesel and a kerb in Feb 2019
2017 SV650 AL7 - naked and unashamed
Sharky
On the street
Posts: 33
Joined: Wed Aug 10, 2016 1:38 pm
Country: United States
Suzuki 2-Strokes: 71 T500 Titan

Re: t500 question about idle weirdness

Post by Sharky »

Huh, had no idea that was the standard operating procedure. I had no chance to start or ride this bike before teardown. That makes me feel a lot better about the cold starting. I always prime, but maybe kicking over before start might help. But this makes me feel like at least I am not completely that far out on my jetting.
sportston
Expert racer
Posts: 1119
Joined: Wed Jul 10, 2013 12:04 pm
Country: England, UK
Suzuki 2-Strokes: FZ50, GP100, RG125 Gamma, GT380, Bandit 1200S

Re: t500 question about idle weirdness

Post by sportston »

Sharky wrote:Once it starts, it wants to hang at 3000 rpm and I have to blip it to lower idle back down to where it is set around 1200. It lowers the idle slowly, and did this with the larger 32.5 pilot jet as well.
Most likely either you have an inlet leak of some sort or a sticky/badly adjusted throttle.
Suggest you check your throttle cables and their adjustment first. Are the cables stiff and in need of replacement or lubrication?
Are the throttle slides free-moving and closing fully?
Are your carbs correctly synchronised?
Also make sure your pilot screws are set correctly.
Also check rubber flanges have no cracks in them and are sealed well to the engine and carbs. You can check for inlet leaks while the engine is running by spraying Easy-Start around any potential leak sites. If the engine note falters or increases you have a leak there.
Hopefully that will be of some help to you.
Good Luck
Tom
Sharky
On the street
Posts: 33
Joined: Wed Aug 10, 2016 1:38 pm
Country: United States
Suzuki 2-Strokes: 71 T500 Titan

Re: t500 question about idle weirdness

Post by Sharky »

I agree with the possible inlet leak. I have checked, and thought I solved what was there for leaking at the gasket of the boot using gasket sealer. I am pretty sure that was solved. I also made sure it wasn't the throttles sticking manually with my finger on the slide. They are both bottoming out against the adjustment screw. I am convinced I am sucking air somewhere, but where? I have a second set of intake boots, so replacing and hoping that it changes something won't be a huge hassle. But they were soft new replacements in the first place.

I am running more oil than I should be per the marks on the oiler, which I think is clouding the issue as far as what the plugs look like, so today is going to be adjusting that back to exactly the mark.

Used a carb sync tool to get the carbs pretty well in line with each other.

I think I am going to have to rig up a better leak down test than the one that I used before to know for sure.

Thanks all.
sportston
Expert racer
Posts: 1119
Joined: Wed Jul 10, 2013 12:04 pm
Country: England, UK
Suzuki 2-Strokes: FZ50, GP100, RG125 Gamma, GT380, Bandit 1200S

Re: t500 question about idle weirdness

Post by sportston »

Check oil line banjos are not leaking. Could suck air in there?
A new set of dowty washers are quite cheap.
Post Reply