1977 XS650D Weak Electric Start

[WilliamJ]

Hello Everyone,

I have a 1977 XS650D that starts fine with kick start but the electric start seams tired/does not get it started.

Whenever I press the starter button it cranks over slowly and only ever starts if the engine is already hot and I am lucky.

My bike doesn't have a decompression mechanism on the left hand exhaust valve cover and I am wondering if my bike should have one?

I suspect its just a tired battery but wanted to be sure that its not a missing part or something (since the bike runs and (kick) starts fine as it is) before I go and buy a new battery.

Thanks in advance for your help!

 

[5twins]

No, your model doesn't (and shouldn't) have the decompression device on the left exhaust valve. Yamaha stopped using it after a year or so because they found it wasn't necessary. Yes, you may need a new battery. The ignition needs battery power to function initially until the motor fires and the charging system kicks in. The starter sucks a lot of power and if your battery is low or old and wearing out (which would make it's charge low), the starter may be using all the available power which doesn't leave any for the ignition. It will crank over but not start. Kicking it doesn't use any extra battery power so there's plenty to run the ignition.

 

[gggGary]

It might be your battery but there are several other areas that can cause a sluggish starter, bad wires and connections both +12 and ground. Check and clean the big red wire connections at battery and solenoid. Remove and check both ends of the ground strap, I've found many bad ground straps and it is always a check item on my wake up list. The solenoid it's self can have corroded internal contacts. The wire connection at the starter can be bad, but be real careful down there, it's easy to twist off a wire inside the starter when "checking" that connection nut. Though not common, a bad shaft seal can allow engine oil into the starter and or the starter brushes can be worn, dirty.

 

[grizld1]

Good suggestions, guys. If connection cleanups don't make the starter spin the engine like it should, download the factory manual from https://www.biker.net. You'll find instructions for cleaning up the starter motor commutator; makes a helluva difference.

 

[WilliamJ]

Thanks everyone!!! I’ll check all the connections and if everything checks out I’ll be looking for a new battery. I also plan on checking the voltage of the battery to see if there is any indication of a bad battery there. I
Thanks again!!

 

[gggGary]

Freshly charged from a plug in charger it should light a taillight for 1/2 an hour? and still be good to start the bike.