Bike stalls when hot and rolling

[benjaminanctil]

Hi everyone,

I have a 1996 Suzuki intruder 1400. Last summer I changed the rectifier because it wasnt giving steady current and the back was stalling when riding. It started back and stalled a few minutes after. I changed the part and the problem seemed to be solved. However, I had the same problem this year. I changed the carburetor and the spark plug because they were burn. The float was broken in the rear carburetor. It dit the same problem ( stalling when rolling). So I decided to buy another rectifier. The one I had was half the size of the original and it gave 17 volt to the battery. The new one have 13.5 so I thought it was repaired. I went on a 1h ride on nothing happen. Then, one other day, I was going on the highway and it suddenly stalled. I have to wait 15 min before it would start again. Then I rolled for 10 min, stalled again, waited 10 min and finally went back home.

Is any of you has an idea of what can be wrong ? Could it be an electrical problem. I heard about 30 amp fuse, triggers. Your help will be much appreciated. Thank you !

[sgtcall]

Do you have Star Washers on the battery connections? Simple things first.

[benjaminanctil]

No I don't have. But the connections are not loose

[enforcer]

First check the idle. It needs to be up around 1000-1100 RPM. Any lower and it will stall.

Do you mean coasting? (Clutch pulled in, rolling)

If so, there's a controversial fix that seems to help. Add a washer under the springs on the coast valve diaphragms.

[benjaminanctil]

Correct, the idle was in fact too low. The bike was stalling when idle with the clutch pulled in at a stop. I raised it a little and it was correct. But the main problem remains. The bike stalls when I'm riding normal speed. It starts to skip and then the engine stalls. The temperature is normal on both cylinder. It cools down a little and it will start back and do the same thing after a few minutes.

[Herb]

Is something stopping the fuel flow? Have you tried switching to reserve when it happens? Can you try to prime the fuel pump and hear it ticking when it happens?

If not fuel flow I would consider a heat related problem with the igniter unit.

You might carry a spare spark plug and try checking for spark when the problem happens. You would need to leave one of the spark plug covers off so it would be easy to switch the plug wire to the spar plug.

DO NOT try to remove a plug from a hot engine, it can pull the threads on the spark plug hole.

[enforcer]

Correct, the idle was in fact too low. The bike was stalling when idle with the clutch pulled in at a stop. I raised it a little and it was correct. But the main problem remains. The bike stalls when I'm riding normal speed. It starts to skip and then the engine stalls. The temperature is normal on both cylinder. It cools down a little and it will start back and do the same thing after a few minutes.

But it will idle all day long?

13.5 isn't high enough to really charge the battery. It should be 13.8-14.2 while idling and maybe slightly higher while riding. It could very well be your battery has taken a crap from the over charge. Take it in and have it load tested. You may have the volts but not the amps.

[surass]

If your batt is not taking a crap, maybe the stator is?

[enforcer]

If your batt is not taking a crap, maybe the stator is?

If it's kicking out at least 17V, I doubt it.

[surass]

If your batt is not taking a crap, maybe the stator is?

If it's kicking out at least 17V, I doubt it.

true dat but I think he said that was R/R out? How much voltage you getting from the batt while its running?

[Herb]

I will guarantee that if the bat is the problem it would NOT restart after letting it cool down for a half an hour.

Been there done that.

My 99 shows about 13.8. at about 2000 rpm and above, when the battery is fully charged. Never have a problem with it.

[surass]

Got this info from a smart guy on another forum. It's worth the read...

TO CHECK CHARGING SYSTEM

The first thing to check if you suspect a charging problem is the battery and the wires attached to it. If the wires are loose, make sure to tighten them up. If you see any corrosion, disconnect them and clean them off with a wire brush before re-attaching. Check each cell on the motorcycle battery to make sure the electrolyte is covering the plates, if not, carefully add distilled water until the fluid reaches the "top" line on the side of the battery. If your battery is less than fully charged, use a low amperage charger (1 to 3 amps) and charge it until the indicator says it's full. If it doesn't take a full charge, replace it with a new one.

When your wires are clean and secure and the battery fully charged, you can get started checking the system. Perform the following checks:

Battery: Turn ohmeter to the DC Volts setting that can read 12V or more. With your motorcycle off, read from Positive to Negative making sure the Red is +, Black is -- If battery is good you should get about 12.5 to 13.5 volts

Charging: Using same multimeter range, start the motorcycle and run RPM's up to above idle.Voltage should increase to several volts above initial reading, usually to about 14.7 V Voltage should not go much higher than 14.7 V. If voltage goes alot higher when you rev the engine, you could be overcharging due to a voltage reg problem. If voltage doesn't change, your motorcycle is not charging.

Stator: If your motorcycle is not charging, you need to check the stator. Locate the plug for the stator on the front of the engine block. Switch the multimeter to OHMS range on the lowest setting, usually 10 ohms. With the motorcycle off, read between the 2 pins or holes in the block. These should show continuity. If your meter is accurate you could read 1 to 3 ohms, but cheaper meters will not be that accurate. As long there is continuity it passes this test.

Now change the setting on the multimeter to the highest OHM range like 100K. Touch one probe to a pin or hole in the engine, the other to the engine case or a metal bolt on the engine. The meter should not move. Try the other pin the same way and it also shouldn't move. If you get any reading the stator is shorted and must be replaced. This requires special tools and you should consider taking it to a shop. If you get no movement on the meter, it's not shorted out so you need to check for output.

To check for output, change multimeter to AC Volts setting over 100 Volts. With the alternator plug disconnected, start the bike. Use the probes (not polarity sensitive) to read between the pins or holes in the engine block. You should read about 20V per 1000 rpm's. At idle expect about 25V, as you rev the engine it will increase to 60 or 70 Volts. If it does your stator is OK, if you get no output the stator is bad and you will need to replace it or take it to a shop.

Voltage Regulator: If your stator is not shorted to ground and has the proper output, your regulator is most likely the culprit. If your stator checks out OK but battery voltage doesn't increase when the motorcycle is running, the regulator isn't doing it's job and needs to be replaced. It's an easy swap, just make sure you bring the old one with you to make sure they give you the correct unit. If the battery voltage goes too high when you rev the motorcycle the regulator isn't limiting the voltage and again it needs replacement.