Yamaha 2stroke question

[seasick]

Saltwater Series 2.
He did say that if the fuel pumps are the problem, then priming the bulb before a restart would make the problem worse.

That's pretty funny to me.
Priming will make the problem worse... Worse than what? The motor doesn't start now, will it really not start if the bulb is pumped???

 

[boslaw]

I guess he meant that if it takes 10 min now and eventually restarts, it will take 20 min if I prime the pump? As I said, I'm just a noob at this.

 

[enfish]

I'm watching this thread because my carbed SWS has been doing this for years and has every Yamaha certified mechanic stumped. Motor starts right up on the first try in about 2 seconds when cold, even when sitting for 6 months (fully mechanically choked). But semi-warm, it's a PITA to get started (i.e. after sitting off for 15-30 minutes). It fires up fine immediately if it's been off for a few minutes, and fires up fine if it's been sitting for 1+ hours. It's the sitting for 15-30 minute timeframe where it has problem. Turn the key and it will kick over enough to disengage the Bendix on the starter, but then coughs and dies. Advancing the throttle and tapping the electric choke intermittently while the key is in the start position usually gets it to fire up. Priming the fuel bulb makes zero noticeable difference.

We've been running 87 octane E10 gas (E10 is all we can get in CA). But the end of last season we switched over to 91 octane (also E10). I don't have enough semi-warm starting attempts on it yet to know for sure if it helps, but it is idling smoother with the higher octane.

Boslaw, your and my problem seem pretty darn similar. The good news is it's never not started eventually. But the adrenaline rush you get when you're 30 miles offshore and the motor doesn't immediately start is not the good kind of adrenaline rush.

 

[enfish]

The strange fact is that the engine starts fine when either cold or sitting after a run. Bad LP pumps doesn't explain that. Carb seepage might but they would have the draining when resting (and the motor would be hard to start cold)

If after sitting and sitting for a while, the motor starts right up, it isn't a fuel issue in my opinion with the possible exception of vapor lock. I am thinking the problem is heat related. I am not sure if the fuel is cooled by water or if the ECI is also water cooled. If so, a partial blockage of the cooling system might explain a vapor lock condition.

Based on my experience with my similar problem, I think this is going down the right path with a vapor lock issue.

 

[boslaw]

Mine usually takes 4 tries to start up from cold, fully choked, but when it starts it idles at a good speed. If run for 30 min and then shut the motor for 30min-1 hour, my next start will take 10 tries. During those 10 tries, the motor never really turns over. Just wheezes until one magical try gets it to start, but if I don't give it gas at that point, it's idling so slow that it will stall.

Just for reference, I was offshore on Saturday fishing. I shut the motor for at least an hour while drifting. The motor did not want to start when I tried to get back home. As usual, trying 6 or 7 times, pulling choke, pushing choke back in, eventually got it going.

 

[seasick]

OnoEric
Interesting info. It's too bad you never figured it out. I would expect that if it is a common problem with those series S200s, I would have heard about it more often.
There is some validity to the summer/winter gas blend comments as far a volatility and potential vapor lock go but the thing about that which puzzles me is that since there would still be gas in the carb bowls, the motor should at a minimum stutter start and die.
Gee, did I ask if it doesn't fire at all and stutter and spit or it just cranks without firing?

I would also think that pumping the primer would overcome a vapor lock since that motor doesn't have a high pressure pump, just LP pumps.

 

[enfish]

Mine usually takes 4 tries to start up from cold, fully choked, but when it starts it idles at a good speed. If run for 30 min and then shut the motor for 30min-1 hour, my next start will take 10 tries. During those 10 tries, the motor never really turns over. Just wheezes until one magical try gets it to start, but if I don't give it gas at that point, it's idling so slow that it will stall.

Just for reference, I was offshore on Saturday fishing. I shut the motor for at least an hour while drifting. The motor did not want to start when I tried to get back home. As usual, trying 6 or 7 times, pulling choke, pushing choke back in, eventually got it going.

Interesting. I have the same idling problem. It idles too low (400 RPM) after a semi-warm start and will stall. So I have to keep the throttle advanced in neutral and be quick when pulling the throttle back and then forward to shift into gear to keep it running.

 

[enfish]

Gee, did I ask if it doesn't fire at all and stutter and spit or it just cranks without firing?

In my case, it coughs enough to disengage the starter Bendix almost immediately upon turning the key but then also immediately quits. This seems a bit different than boslaw's problem. So whether we have the same problem, and he just has a more severe case than I do, or we have different problems, I'm not sure.

That's what is leading me to believing it's a vapor lock issue. I get the initial flash of any vapor trapped in the cylinders igniting, but there's fuel starvation after that.

 

[boslaw]

A google search finds a bunch of posts with the same problem over the years but no clear solution that I can discern.

 

[seasick]

is the choke electrical on those motors? What disengages it, a temp sensor signal ?

When the motor finally starts after the several tries, does it smoke more than usual and if so, what color is the smoke. ( trying to confirm a too lean mixture or a too rich mixture)

The low idle could be the lack of fuel or the wrong fuel/air mix.

One more question; when running 'normally' if you drop the throttle to idle , does it idle roughly and what is the idle speed or does the low idle only occur after a shutdown and restart.

I did read those posts about the same issue but as mentioned, no solutions were presented.

I think I am unable to figure this one out.

 

[boslaw]

Choke is manual pull switch on the motor.
No smoke on the restart.
low idle only occurs after rough restart. Putting the motor into neutral after 1st start of the day idles fine.

 

[enfish]

Choke is manual pull switch on the motor.
No smoke on the restart.
low idle only occurs after rough restart. Putting the motor into neutral after 1st start of the day idles fine.

Same for me. No smoke on restart, and low idle only occurs after restart. If I don't shut the motor off, it will idle nicely at 600-700 RPM all day without missing a beat. After a restart, it wants to idle at 400-500 RPM and stalls out with a sneeze.

I've got a mechanical choke on the motor and a manual electric choke on the helm (momentary toggle switch to engage). Mechanical choke is much more aggressive and is used for cold starts. The electric choke is marginal for cold starts.

 

[enfish]

boslaw, what fuel are you running? I've been running 87 octane E10 with Ring-Free ever since E10 became the only fuel readily available in CA about 10 years ago, but switched over to 91 octane E10 at the end of last year. There was a noticeable difference in the idle smoothness with the 91 octane, so I'm cautiously hopeful this will help the problem. Time will tell since I haven't splashed the boat yet this year, but I did start it up a couple weeks ago on the hose and it fired right up. Since everything on the motor seems to be in spec and functioning properly, I am leaning towards this being a fuel problem.

 

[seasick]

Same for me. No smoke on restart, and low idle only occurs after restart. If I don't shut the motor off, it will idle nicely at 600-700 RPM all day without missing a beat. After a restart, it wants to idle at 400-500 RPM and stalls out with a sneeze.

I've got a mechanical choke on the motor and a manual electric choke on the helm (momentary toggle switch to engage). Mechanical choke is much more aggressive and is used for cold starts. The electric choke is marginal for cold starts.

How is the manual choke disengaged as compared to the electric choke. I thing thee manual has to be manually released but the electric is 'automatic' Will the electric choke engage if the motor is hot?

Thinking of all kinds of nasty problems, a few things come to mind, all possibly heat related.
The first is bad reed valves that when hot, don't seat correctly but seal better as the mass of the motor cools.
The second could be related to reeds or something worse; An air leak in the crankcase (worse when the motor sits hot) that results in the low pressure pumps not getting enough vacuum to operate and possible lower compression. A fuel pressure test might show a pump problem.
Note that the carbed model motor works differently fuel wise than SX model with a VST tank. The motor in this thread has no VST or high pressure pump.

 

[boslaw]

I'm not sure if I have an electric choke or if it works. There's a round rubber disc on throttle shaft that you're supposed to push when turning the key. I assume that's the electric choke. If it is, mine has never seemed to do anything.

On the first start of the day, I have to manually pull the choke on the motor and turn the key a few times. If I can't get it to start by the third try, I push the manual choke to half-way and that usually does the trick. When the motor starts, I hustle back to push the choke in else the motor will stall. Once I push the choke back in, the motor idles at a good speed and then I'm underway.

With hot starts, I've tried both with and without the manual choke. Doesn't seem to make a difference, or if it does, I can't really tell given it takes me 10 tries to get the motor started again and I'm usually trying every option and sweating at that point. Turning the key for a hot start sounds and feels very different. With a cold start, I can hear the motor cranking and trying to engage. With a hot start, the motor sounds like it's wheezing and nothing is engaging. Sometimes I get barely any sound at all.

As for fuel, I'm using whatever is avail at the gas dock, but I do use Yamalube Ring Free with every fill up. I believe MA also only allows E10 but I'm not sure what octane I'm getting at the pumps.

 

[enfish]

How is the manual choke disengaged as compared to the electric choke.

Manual choke on the motor is operated by pulling the slider bar (or whatever it's called) out from the bottom cowling, starting the motor with the throttle advanced, then quickly running back to the motor to push the choke back in before the motor bogs down, then quickly running back to the helm to pull back on the throttle before it over-revs. It's a fun process LOL. But it's only done once if the motor has been sitting for a week or more while the boat is still on the trailer on the ramp.

I thing thee manual has to be manually released but the electric is 'automatic'

The electric, as far as I'm aware, is also completely manually operated. There is a momentary toggle switch between the killswitch lanyard clip and the ignition key. The process for that varies depending on how warm the motor is but it's typically hold the switch in the engaged position, turn the key to start until the motor fires, release the key but continue holding the choke in the engaged position for another half second or so before releasing. The variation is on how long I hold the choke engaged, and that's done completely by listening to the motor. I couldn't tell you what my cues are, but they are obvious when I'm there. Sometimes I have to release the choke before the motor fires up.

Will the electric choke engage if the motor is hot?

As far as I'm aware, only if I manually engage it with the toggle switch. I don't believe there is an automatic choke on my vintage motor... at least it doesn't act like there is. This may be different than boslaw's motor. I don't know what changes were made between the SWS and the SWSII.

Thinking of all kinds of nasty problems, a few things come to mind, all possibly heat related.
The first is bad reed valves that when hot, don't seat correctly but seal better as the mass of the motor cools.
The second could be related to reeds or something worse; An air leak in the crankcase (worse when the motor sits hot) that results in the low pressure pumps not getting enough vacuum to operate and possible lower compression. A fuel pressure test might show a pump problem.
Note that the carbed model motor works differently fuel wise than SX model with a VST tank. The motor in this thread has no VST or high pressure pump.

That's good info to know. All of your ideas seem plausible, with the reed valve theory seeming most plausible. What's interesting is I think it would be related to how different parts of the motor cool and heat at different rates. Because after a hard restart, the idle will continue to be low until the motor is run hard (boat up on plane), then it's fine again. So it's like it needs the motor to get completely hot again before it starts running normally, which is a temperature it never reaches at idle or fast idle. But why would it operate fine from a cold start...?? I'm going to spend some time reading the shop manual to better understand how the motor works. My motor is model 175TXRT.

 

[Bottomfeeder]

Disclaimer! I am not a outboard mechanic .
But I do have a 1995 225 saltwater on a 225. Not sure it’s so different from a 1997 .
a lot of what’s being discussed is confusing, such as
“ I push the button on the throttle to choke “
pretty sure that allows you to put the throttle in neutral.
when I turn my key, there are 3 beeps, that is the auto prime that’s detailed below.
There is no other choke system.
Do some more research on your engine with the correct model number.
Best of luck !

Prime Start Enrichment
Additional enrichment is necessary to start a cold engine. Fuel-air mixes do not want to vaporize in a cold engine. In order to get a little fuel to
vaporize, a lot of fuel is dumped into the engine. On most V4 and V6 engines, a choke plate is used for cold starts. This plate restricts air entering the engine and increases the fuel-air ratio. The enrichment system on the 90° 225HP engines (1990 - 1995) is con*****ed by a microprocessor. The choke switch and choke valve system have been eliminated. Temperature and throttle position are monitored and enrichment is automatic. An electromagnetic valve unit with a pair of injectors with different diameters are used to provide enrichment. Timing advance is also con*****ed by the microprocessor, thus eliminating the need to advance the throttle during startup.

 

[boslaw]

Manual choke on the motor is operated by pulling the slider bar (or whatever it's called) out from the bottom cowling

>>>>>>My manual choke is the same as yours - pull out the switch on the motor.

, starting the motor with the throttle advanced,

>>>>>>I can only start my motor with the throttle in neutral.

The electric, as far as I'm aware, is also completely manually operated.

>>>>>>I do not have a choke switch like shown in your picture. I always thought the round rubber circle on your throttle arm was a push button choke but it does nothing on mine. It's probably just covering a nut that's holding the throttle lever onto the remote control box


>>>>>>My motor is Yamaha S200TXRV

 

[enfish]

>>>>>>I do not have a choke switch like shown in your picture. I always thought the round rubber circle on your throttle arm was a push button choke but it does nothing on mine. It's probably just covering a nut that's holding the throttle lever onto the remote control box

The rubber circle on the throttle arm is the button that disengages the shift cable so you can advance the throttle in neutral. Push and hold it in while pushing the throttle lever forward and you'll stay in neutral and be able to start the motor with the throttle advanced.

 

[Father's Day]

Thanks very much. The motor usually starts after brief stops but not long stops (>30 min). I'll pump the primer bulb next time to see if that helps the situation. It's always embarrassing when you're at the beach with the kids and you have to spend 10 min trying to start your wheezing motor with your fingers crossed

Had same issue my mechanic told me to put it in neutral and give it some gas and then start it worked for me