I thought it was the stator but now it gets weird | GTAMotorcycle.com

I thought it was the stator but now it gets weird

H

healer677

Well-known member
ok -here's the quick synopsis
It's a 2007 Honda Shadow 750DC with less than 10k on it. The bike was being erratic and losing power on acceleration since last summer- it even started backfiring. Then last weekend on a test ride for a brand new fully charged battery the bike backfired then died. It wouldn't produce power at first then after a minute the power was back -starter was working but bike wouldn't start. So off to the shop.

Prior to the ride I suspected it was a battery issue. Before the ride I checked the battery on idle and it was fine - it wasn't overcharging (so initially I ruled out the voltage regulator).

Now - the bike's stator is reading within specs (according to the Clymers manual). Bike is cold. The battery is at 12.5 cold.

Could it be a coil issue?

At this point in time I'm willing to invest in a new stator and coil, even a voltage regulator.

Any suggestions?
 
Don't throw parts at it....test things out and diagnose it.....
 
Could be many things with electrical.

Check your plugs.
 
So far the stators readings are within spec and so is the battery. The voltage regulator hasn't indicated a problem. Kick stand sensor is ok. Kill switch is ok. Terminals on the battery is ok at both ends. Starter is ok- it cranks but does not turn the engine over.

SO now I'm stuck on ideas. What do I check at this point? I'm guessing re-check the coil?
 
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Plugs were replaced last year - now, plugs are ok - not fouled. Wires for plugs are intact -no external scorch marks -the inside terminals look brand new still.

The bike was winter stored with the tank off -so the fuel in it is new -Shell whatever the premium brand is. The carbs were fogged prior to storage and carb cleaned prior to remounting the tank. All the vacuum lines were rechecked prior to the remount. So I figured that rules out fuel issues.
 
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healer677 said:
Plugs were replaced last year - now, plugs are ok - not fouled. Wires for plugs are intact -no external scorch marks -the inside terminals look brand new still.

The bike was winter stored with the tank off -so the fuel in it is new -Shell whatever the premium brand is. The carbs were fogged prior to storage and carb cleaned prior to remounting the tank. All the vacuum lines were rechecked prior to the remount. So I figured that rules out fuel issues.
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PM'd you...
 
What you have not provided us, is the voltage across the battery terminals with the engine running at various speeds. You've only given us the at-rest voltage of the battery.

If the voltage across the battery terminals is between 13.5 and 15.3 volts (this is a generic range - your particular bike's service manual may give a narrower range within this) regardless of engine speed as long as it is above idle, your entire charging system is OK and you can rule out all stator or voltage regulator related issues. The problem lies elsewhere.
 
Prior to the test ride, I did run the meter across the terminals. At rest but with my hand on the throttle giving it some gas, the voltage did got up to 14 and changeish. What lead me to an electrical source was the fact that it came to a dead stall about 2 kms from the start point and, at first attempt the indicator lights did not even display.
A minute or so later they did display but the bike wouldn't turn over.

If not electrical where should I look next?
 
Starter is turning engine over..is it fast enough for the bike to start? Voltage on the battery could be okay but if you've fried a cell the amp's won't be enough (does the bike start with a boost). Not sure if our bikes are at all alike but I have a HES (hall effect sensor) that controls the ignition timing. As my HES was pooping my bike would surge or lose power for a second..backfire once in awhile then finally died. I could crank like crazy but would get not start. I initially thought my coils but it would've meant a failure of both coils. You can check resistance at the coils as your next lead.
 
I had a similar thing happen to my T-rex. Turns out it was the tip over sensor, someone had mounted it poorly. Maybe your's is loose or going bad (even though it's a simple mechanical device).

Of course best bet is to diagnois everything before throwing money at it.

My symptoms were, bike was hard to start, random starts. Starter would crank but t-rex wouldn't start. Once I got it started it would die randomly at lights or backfire at times.
 
Thanks for the input guys -ok next stop, off it goes to a pro. I'm sure his luck end patience will be better than mine.
 
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I think that 12.5 volts is marginal and suspect the battery.
 
If all your lights went out and then went back on it sounds like an electrical short. With a multimeter, check your battery terminals, common ground, and master fuse. All can knock out your bike like this. Check all your fuses using a multimeter.
 
My saviour came from the most unlikely source. Hats off to the guys at Vespa West.
As a rule they do not service motorcycles, just Vespas; but they took pity on me and took on the project. 48 hours later -ta-dah the answer is...........voltage regulator.

They got me a good price on an after market regulator vs Honda's intial quote - boom. Bike runs like a dream.

They basically re-checked everything and told me -it wasn't the battery, no- I don't need a new stator, no it's not shorting.

I was a one off. The shop looked busy enough with customr bikes but they decided they would take a peek. I can't thank them enough.
 
atss2006 said:
Starter is turning engine over..is it fast enough for the bike to start? Voltage on the battery could be okay but if you've fried a cell the amp's won't be enough (does the bike start with a boost). Not sure if our bikes are at all alike but I have a HES (hall effect sensor) that controls the ignition timing. As my HES was pooping my bike would surge or lose power for a second..backfire once in awhile then finally died. I could crank like crazy but would get not start. I initially thought my coils but it would've meant a failure of both coils. You can check resistance at the coils as your next lead.
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jap bikes don't have hes in their electrics. only bmw's do.
 
In talking to the shop mechanics it turns out they do do bikes -mostly Dukes and Aprillas- the mechanic had a beautiful 850 Mana. They also do the odd newer Jap bikes but not the older vintage ones (parts harder to find).
Looks like my bike found a home away from home when a problem gets past me and startes driving me crazy.
It's hard to find good guys that can look after my bike and not hose me at the same time. I've heard and at times seen some horrible situations. These guys treated me fairly and well.
 
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