won't start [SOLVED] was battery then starter relay

[galen]

Swapped out the battery and hooked up a charged booster power pack with more than double the default battery.
300 won't start, shows low battery alert.
Is my 300 gone mental?

[ophelia]

The battery indicator stays on until a second or two after the bike has started. It may not be meaningful.

What sounds does the bike make when you thumb the starter?
Was the bike running before? What's the mileage?
Is the kill switch on run?
Do you have fresh gas?

[kneeslider]

Few things to trouble shoot with.

1) when you turn on the ignition, do you hear the fuel pump hum?
2) is your side stand up?
3) check you spark plug
4) check the spark plug cap
5) kill switch


these bikes are very basic, they just need fuel, ignition and air to run.

[CROSSBOLT]

Too much information missing. Start giving information suggested by kneeslider and ophelia. Please include why you progressed to the elaborate battery and booster scheme. The symptoms that led you to the battery scheme may give the rest of us a clue to what is the cause.

[galen]

yes, here is more info
downtown 300i 2013
2,000km

side stand is up
lights come up, pump sounds,
kill switch set to run position

updates:
managed to get a better connect with booster pack and recharged batteries I was using.
My charger was reporting full charges when battery was not fully charged, I switched to a smart charger.
battery is only ctx9-bs type (9A)
I also tried UTX10-bs
Now the battery light is out and the oil light is on.

I will check the oil system next.

[CROSSBOLT]

Your battery is WAY TOO small! Your battery box will take a much larger battery and should have one that boasts more than 120 cold cranking amps (cca). The designator for a DT300I is something like ES12-BS. A battery that has a 9 or 10 where the 12 is is for a 150 or smaller. That is part of your problem.

I have the same bike, same year! Dealer stuck a cheap. 120 cca size 12 battery in when he set up the bike. I have a post with pictures that covers this whole deal. Of crummy, undersized batteries, that is.

[ophelia]

Yuasa specifies a YTX12-BS maintenance-free battery for the Downtown 300i.

They have a pretty good battery lookup tool.

Is the oil pressure light on after the bike is started and idling, or when the ignition is on and engine is off? There's not much oil pressure to detect when the engine is not running.

[galen]

no turn over at all

[galen]

Your battery is WAY TOO small! Your battery box will take a much larger battery and should have one that boasts more than 120 cold cranking amps (cca). The designator for a DT300I is something like ES12-BS. A battery that has a 9 or 10 where the 12 is is for a 150 or smaller. That is part of your problem.

I have the same bike, same year! Dealer stuck a cheap. 120 cca size 12 battery in when he set up the bike. I have a post with pictures that covers this whole deal. Of crummy, undersized batteries, that is.

thanks,
I've seen somewhere the 2013 model used the smaller battery box, the 2014 used the larger battery

ytx9-bs CCA=120 8A  AGM
I had tried a utz10-bs in it
8.6A  CCA 190
6"w x 3.5"d x 3.75"h
YTZ10S
but that battery was too old

[CROSSBOLT]

I have only seen the two DT300I machines I have owned. I have a hard time believing they would change the battery size on a model that has proven to be a reliable starter. Especially since they have made NO changes to the 500i which has been a NOTORIOUS marginal starting nightmare.

[galen]

updates:
I had a mechanic look at the 300 and we found the starter relay was bad (tried a used one from another machine, it was bad as well). We could jump the relay and start the 300 with ease. The starter switch activated power into the relay.
The service manual did not mention anything about relay faults nor did it mention several screws needed to remove panels for access. Nothing was forced nor broken.
New relays are on order.

[CROSSBOLT]

That makes sense. A description of how it was acting could have pointed to that. Glad you got it sorted.

[galen]

not sorted out, 300 is dead.
obtained a compatible 12v relay,
installed it and attempted a startup.
The relay worked and cranked the engine.
Engine started.
Starter would not stop!
electrical smoke was detected.
Kill switched the engine.
starter would not stop.
disconnected  black from relay.
starter stopped.
removed relay and tested it ok with bench tools.
300 will not show any signs of life.
battery is good.
all fuses tested with tester.
no signs of burnt out wires.

any ideas?
this is not covered in the service manual

[CROSSBOLT]

First thought the start relay welded it's contacts but you say it tested OK on the bench later. When you removed the start relay was there a skinny red wire hooked to where the fat red wire was? That skinny red wire powers all other systems on the bike.

[galen]

facepalm myself, yes the RED main wire was not connected.

The replacement starter relay is bad.
On the bench it will work fine.
When installed on the 300 in testing mode it works fine UNTIL
the relay is placed back in position with some strain on the poles from the wires, then
the relay will continue to be closed (unstoppable). The engine kill switch works fine, I have to disconnect any terminal on the relay or the battery itself.

Time to order another relay.

Thank you for the help