DT30 2 Stroke 2004 thermostat

[Polycraft]

I was wondering if someone could help me find where the thermostat is on this model (I think it's 2006 actually). If it's easy to access I might pull it out myself. I suspect it might be stuck open. I have the problem of stalling in gear after a long run and trying to restart after 20 min or so. If the motor is now cold and the thermostat still open then this could lead to the mixture being too rich and the engine stalling. Also when on the flusher and the engine idling it only takes a couple of minutes for the water to come out of the exhaust. I have heard this can be a sign of a thermostat being stuck open, but they were speaking generally and not this make and model specifically. Also are there any other ideas as to why it is sometimes stalling in gear (note it runs fine first thing)?

[Murray]

https://www.boats.net/catalog/suzuki...001/thermostat

Thermostat should be at the top of the engine. The above link will give you an idea what to look for.

[Solarman]

It doesn't sound like thermostat problems if motor has water in exhaust after couple mins, this sounds normal.

Thermostat is located near/at the top of the (top) cylinder head.

Your description sounds a little more along the lines of a vapor- lock situation. Try to bring rpms down a little more gradually, and get motor to idle a few mins before shutting down.

Stalling in gear, if idling, may also indicate idle setting is too low? If stalling when above idling, it might be some trash build-up in carbs from old fuel, or sitting up for too much time, without a good additive in fuel to keep carbs clean, and fuel fresh.

Also, if mixture screws have been changed, they need to all (one for each carb) be set identically back to factory/service manual setting. If carbs are dirty, they need to be cleaned.

If fuel injected (no carbs), then cleaning filters, and checking fuel pressure at fuel rail may be needed?

Good luck, post back on what you find out.

[Polycraft]

Thanks for that - the vapour lock idea sounds plausible. It never happen early in a trip - just starting up after long runs, That's why I thought temperature might have something to do with it. The thermostat was actually changed by my mechanic he said it was stuck open - but the stalling problem remained.

[Polycraft]

An update on this - I had a look under the cowl and noticed the fuel line was touching the engine block. This might explain the problem if it's vapour lock. There is a holder bracket nearby but it's not easy to route the fuel line through this. Perhaps something has fallen off or it's at the wrong angle? I might just use a zip tie to hold the fuel line away from the block - using the bracket as an anchor. This should be safe to do? Also I will use some of the heat insulation wrap designed for these situations.

[Murray]

Yes you can use a zip tie to keep your fuel line off the block just make sure that the zip tie doesn’t put a kink/restriction in your line. A better idea would be to reroute the fuel line back to factory specifications. The link I posted above is for a 4 stroke not a 2 stroke. To determine what year your engine was manufactured see the link below.

https://www.suzukioutboardforum.com/...5&d=1583952114

[Polycraft]

Yes you can use a zip tie to keep your fuel line off the block just make sure that the zip tie doesn’t put a kink/restriction in your line. A better idea would be to reroute the fuel line back to factory specifications. The link I posted above is for a 4 stroke not a 2 stroke. To determine what year your engine was manufactured see the link below.

https://www.suzukioutboardforum.com/...5&d=1583952114

Thanks for that. I found this diagram (I hope it's OK to put a competitors link up) which shows the clip but not the configuration. Is it supposed to be bent around the hose? A zip tie might have to do for now:

Fuel pump for 2004 Suzuki DT30 | General Export No.1 (P01) sales region, Shadow Black Metallic (0EP), 8011573-632695 (megazip.net)

[Murray]

You are talking about part #10 Clip? A zip tie would work, maybe. IMHO a pipe clamp(small) would be a better option. You want a clamp that will not allow air to sneak in and mess with your carburetor air/fuel mixture.

[Polycraft]

You are talking about part #10 Clip? A zip tie would work, maybe. IMHO a pipe clamp(small) would be a better option. You want a clamp that will not allow air to sneak in and mess with your carburetor air/fuel mixture.

No, part 15. I am not connecting the fuel line to anything - just trying to keep it from touching the engine block and heating up.

[Polycraft]

Well after that it still stalls when I put in in gear, after a long run. I heard bad ignition coils can be a common problem. Also at the previous service the mechanic put the wrong spark plugs in and I have heard this can damage the coil. Would one of those spark plug testers with a flashing light be a good way to test the coil? I would probably have to do it on the water after a long run. Or if it's a cheap part I might just swap it out by way of elimination.