impossible to start with lights ON

[sam95]

Hello,

I have got a sidecar with a FJ1200 frame but the engine is from an FJ1100 (don't ask me why !). I replaced the motorcycle battery by a car battery in the sidecar. The leads between the battery and the connector in the bike are about gauge 4AWG (20mm²).

I can't start my bike with the lights turn on, neither with engine cold nor with engine hot.

Do you think it's normal or is there a problem ?

When engine is started but still cold (first 5 min at least) my idle is very low (below 1000rpm) and if I turn on lights, engine stops. After 5 or 10 min my idle is about 1200rpm, and I can switch lights on and no more problems.

A last question, my starter is not efficient. I pull on the handle, the cable moves well, and the starter set move on the carburetor; but there is no increase of RPM. So I have to control my idle to warm the bike with the throttle handle, and it is not very usefull. Do you have any idea to correct that ?

Thanks for your help.

Sam

[red]

Hello,
I have got a sidecar with a FJ1200 frame but the engine is from an FJ1100 (don't ask me why !). I replaced the motorcycle battery by a car battery in the sidecar. The leads between the battery and the connector in the bike are about gauge 4AWG (20mm²).  I can't start my bike with the lights turn on, neither with engine cold nor with engine hot.  Do you think it's normal or is there a problem ? 
When engine is started but still cold (first 5 min at least) my idle is very low (below 1000rpm) and if I turn on lights, engine stops. After 5 or 10 min my idle is about 1200rpm, and I can switch lights on and no more problems. 
A last question, my starter is not efficient. I pull on the handle, the cable moves well, and the starter set move on the carburetor; but there is no increase of RPM. So I have to control my idle to warm the bike with the throttle handle, and it is not very usefull. Do you have any idea to correct that ?
Thanks for your help.
Sam

Sam,

Try a set of jumper cables from a running car to your sidecar battery.  If that gets things started better, then you have dirty battery terminals or a weak battery, or both.  Battery cables have two ends, each.  Clean all four ends.  Use a charger on the battery, to bring it up.  If the battery does not stay charged, and the cable ends are clean and secure, then try a new battery.

You can wire a relay to take the full battery power straight to the coils.  The relay must be turned on by the ignition circuit.  This may or may not "fix" the headlight problem, but you will definitely  like the way it runs, anyway.

You may be able to get the chokes working with a good carb cleaner.  Run a can or two of Seafoam through the gas tank, mixed with the right amount of gasoline.  The chokes should make the bike run rich, so try the choke control with the engine running warm.  If nothing happens, give the Seafoam a day or three to work it's magic.  Beyond that, the carbs may need to be cleaned and rebuilt.  You can have that done by professionals, if you like.

Cheers,
Red

[FJmonkey]

Hello,

I have got a sidecar with a FJ1200 frame but the engine is from an FJ1100 (don't ask me why !). I replaced the motorcycle battery by a car battery in the sidecar. The leads between the battery and the connector in the bike are about gauge 4AWG (20mm²).

I can't start my bike with the lights turn on, neither with engine cold nor with engine hot.

Do you think it's normal or is there a problem ?

When engine is started but still cold (first 5 min at least) my idle is very low (below 1000rpm) and if I turn on lights, engine stops. After 5 or 10 min my idle is about 1200rpm, and I can switch lights on and no more problems.

A last question, my starter is not efficient. I pull on the handle, the cable moves well, and the starter set move on the carburetor; but there is no increase of RPM. So I have to control my idle to warm the bike with the throttle handle, and it is not very usefull. Do you have any idea to correct that ?

Thanks for your help.

Sam

Sam, the 1100/1200 engines have the cases so switching them out is easy. The issue with your lights and the engine quitting when cold is not normal. You may have a grounding problem. You said the battery is now in the side car and you have 4 AWG, the wire gauge is more than enough, over the top in fact, but it will not cause any problems. Make sure you have a ground wire from the battery to the engine case. The original location is behind the engine and down low near the rear swing arm pivot is. Make sure the ground connection is clean with no paint or debris.

Your cold start issue sounds like the choke is not working. If the choke cable moves and you see the bar on the carbs sliding then you may have clogged choke circuits. If so you will need to get your carbs serviced and cleaned thoroughly. I also found the cold start is easier with #40 pilot jets, I almost don't need the choke and not for long when I do.

The original (2 brush) starter was ok at best and can get tired with age and use. The lest expensive way to get better cranking (hot or cold) is to buy a 4 brush starter from ebay. I have been looking for one myself but the ebay listings are not specific if the starter is 2 or 4 brush design. Maybe a member here has purchased one and post what brand or seller they got it from.

Others will likely post up so good luck and post up when you get your problems fixed. We like to know what solutions worked.

[Pat Conlon]

Also, when you push the starter button and activate the starter relay, your headlight should shut off, then return ON when the starter button is released

[The General]

I too have a car battery on my sidecar. There is a fair bit of Voltage drop and depending on where you have placed the battery it could be a lot. What`s the Voltage at the end of your new leads? How long are they? Any particular reason for changing from standard bike battery? (low RPM at idol is a separate prob.) 

[FJmonkey]

I too have a car battery on my sidecar. There is a fair bit of Voltage drop and depending on where you have placed the battery it could be a lot. What`s the Voltage at the end of your new leads? How long are they? Any particular reason for changing from standard bike battery? (low RPM at idol is a separate prob.) 

With 4 AWG you will not see much voltage drop, try this: http://www.rapidtables.com/calc/wire/voltage-drop-calculator.htm

With 10 feet of 4 AWG pulling 5 amps at 12VDC your drop is 0.025 Volts, 5 feet cuts that in half.

However, if you are measuring a significant voltage drop across your 4 AWG cables, then you have one or more bad connections. Possibly a bad cable.

Some good advice has been offered, pick one problem and solve it. Then get after the next one till you are running well again. 

[racerrad8]

I have been looking for one myself but the ebay listings are not specific if the starter is 2 or 4 brush design.

They are all four brush design. The old style two brush motors are easy to identify as they have the phillips head screws visible in the external case.

http://www.ebay.com/itm/New-FITS-YAMAHA-Starter-FJ-1100-1200-FJ1200-FJ1100-1984-1993-/280364160414?pt=Motorcycles_Parts_Accessories&fits=Make%3AYamaha|Model%3AFJ1200&hash=item414701959e&vxp=mtr

Randy - RPM

[FJmonkey]

They are all four brush design. The old style two brush motors are easy to identify as they have the phillips head screws visible in the external case.
Randy - RPM

Like this Phillips? Are the two long bolts holding the motor together also Phillips?

[racerrad8]

Like this Phillips? Are the two long bolts holding the motor together also Phillips?

Yes, the phillips in the housing, I cant answer about the screws/bolts holding the whole thing together.

Randy - RPM

[wildfire]

As others have said I would first check the quality of the battery by trying to jump it from a good known source. If no improvement in starting then move on to next step of checking electrical system. 

[sam95]

hello,

I thought my battery was Ok, because I bought it new last year.

I will have a look to my connection and ground

Thanks for your ideas, I will keep you informed.