Engine Earth Strap - Gen 1 Fazer - Running Voltage

[BSR67]

Chaps

Is there a engine to frame earth strap? And if so, where is it located?

The battery negative attaches to the start motor mount.

I am getting 13.5v at 5,000 rpm across the battery which feels low. Normally charging systems are 14v+

So, cleaning up contacts/connectors. Battery to starter strap is good. Need to check the other .... if it's there.

Thanks

BSR67

[Trebus]

@BSR67 there isn’t one. 

If the charging is low then check the connector for the reg / rec which can corrode and cause a voltage drop. If that checks out then you may need a new reg / rec, they’re not a bad unit but failures do occur given the age of the bikes.

The losses in the wiring loom can be fairly significant so rule that out first. Some people run new cabling back to the battery to help.

[BSR67]

@BSR67 there isn’t one. 

If the charging is low then check the connector for the reg / rec which can corrode and cause a voltage drop. If that checks out then you may need a new reg / rec, they’re not a bad unit but failures do occur given the age of the bikes.

The losses in the wiring loom can be fairly significant so rule that out first. Some people run new cabling back to the battery to help.

Thanks Trebus.

Tempting to do a MOSFET upgrade as I once did on a former VFR800 VTEC (very weak charging systems/high rate of generator failure due to crap R/R). I'll check the connector from the Reg/Rect. on the Fazer.

The battery to engine earth has no resistance whatsoever so is all good.

I'll update on what I find.

BSR67

[Gaz66]

Chaps

Is there a engine to frame earth strap? And if so, where is it located?

The battery negative attaches to the start motor mount.

I am getting 13.5v at 5,000 rpm across the battery which feels low. Normally charging systems are 14v+

So, cleaning up contacts/connectors. Battery to starter strap is good. Need to check the other .... if it's there.

Thanks

BSR67


.......................................


Yes mate, the ground from battery does indeed run direct to starter motor, which is really a balls up on Yamaha's part.
Front engine mount to frame is rubber damped, so no ground there, only part of motor that's in direct contact with the frame is the rear mount & since the frame & motor are factory painted, there's likely little grounding going on there either, amazes me these old Yams run at all.

It'll pay dividends to add a new copper ground from battery direct to a bare metal point on the frame, lights will work better too as they're pretty dog shit at best, also running a heavy gauge ground from headlamps direct to battery will improve current flow to lamps even further, it's an old copper loom that's well past its best, a better ground is an instant cheap upgrade, charging will be optimised too, minimal cost & time for big benefits, no brainer, testing as is will likely result in poor/incorrect result.

[BSR67]

Chaps

Is there a engine to frame earth strap? And if so, where is it located?

The battery negative attaches to the start motor mount.

I am getting 13.5v at 5,000 rpm across the battery which feels low. Normally charging systems are 14v+

So, cleaning up contacts/connectors. Battery to starter strap is good. Need to check the other .... if it's there.

Thanks

BSR67


.......................................


Yes mate, the ground from battery does indeed run direct to starter motor, which is really a balls up on Yamaha's part.
Front engine mount to frame is rubber damped, so no ground there, only part of motor that's in direct contact with the frame is the rear mount & since the frame & motor are factory painted, there's likely little grounding going on there either, amazes me these old Yams run at all.

It'll pay dividends to add a new copper ground from battery direct to a bare metal point on the frame, lights will work better too as they're pretty dog shit at best, also running a heavy gauge ground from headlamps direct to battery will improve current flow to lamps even further, it's an old copper loom that's well past its best, a better ground is an instant cheap upgrade, charging will be optimised too, minimal cost & time for big benefits, no brainer, testing as is will likely result in poor/incorrect result.

Thanks Gaz66

I'll buy a new earth secondary strap and add.

I did some work cleaning up the plug from the generator to the loom, and loom to R/R. The latter was a little crusty but not awful. I managed to get the voltage to about 13.7/13.8v and on removing the headlight fuse, 14v. But, when raising the revs it dips to 13.5v so suspect regulator. I've bought a used FZS600 one as a benchmark/check which is on the way. I've also bought an generator cover gasket so I can pull the stator and check impedence.

There are no issues with the running of the bike, or charging etc. It's just 'annoying'! I'd expect to get 14v plus at the battery ....

I have in the past upgraded a formerly owned VFR800 VTEC plus my son's GSR600 with an FH020A Mosfet which pumps out 14.4v.

Thanks

BSR67

[Gaz66]

[quote="BSR67" pid="979928" dateline="1746699914"]
Chaps
Is there a engine to frame earth strap? And if so, where is it located?
The battery negative attaches to the start motor mount.
I am getting 13.5v at 5,000 rpm across the battery which feels low. Normally charging systems are 14v+
So, cleaning up contacts/connectors. Battery to starter strap is good. Need to check the other .... if it's there.
Thanks
BSR67
.......................................
Yes mate, the ground from battery does indeed run direct to starter motor, which is really a balls up on Yamaha's part.
Front engine mount to frame is rubber damped, so no ground there, only part of motor that's in direct contact with the frame is the rear mount & since the frame & motor are factory painted, there's likely little grounding going on there either, amazes me these old Yams run at all.
It'll pay dividends to add a new copper ground from battery direct to a bare metal point on the frame, lights will work better too as they're pretty dog shit at best, also running a heavy gauge ground from headlamps direct to battery will improve current flow to lamps even further, it's an old copper loom that's well past its best, a better ground is an instant cheap upgrade, charging will be optimised too, minimal cost & time for big benefits, no brainer, testing as is will likely result in poor/incorrect result.

Thanks Gaz66
I'll buy a new earth secondary strap and add.
I did some work cleaning up the plug from the generator to the loom, and loom to R/R. The latter was a little crusty but not awful. I managed to get the voltage to about 13.7/13.8v and on removing the headlight fuse, 14v. But, when raising the revs it dips to 13.5v so suspect regulator. I've bought a used FZS600 one as a benchmark/check which is on the way. I've also bought an generator cover gasket so I can pull the stator and check impedence.
There are no issues with the running of the bike, or charging etc. It's just 'annoying'! I'd expect to get 14v plus at the battery ....
I have in the past upgraded a formerly owned VFR800 VTEC plus my son's GSR600 with an FH020A Mosfet which pumps out 14.4v.
Thanks
BSR67
...................................


Stator can be tested in situ with cover "ON", just follow loom from stator till you locate the 3 pin plug, unplug stator, then Ohms test all 3 poles between each other with a meter.
Specs are 0.27~0.33 ohms @ 20 degrees C, just run motor for a couple of mins to get some heat into it before testing.
or test it cold, then again at fully operating temp, it'll need a good half hr blast to get motor up to temp.
Compare values tested.
You'll get nowhere trying to test a stock Yamaha R&R with a multi-meter, some just can't be tested with a meter.

Expecting to see 14V @ battery on a 20 plus yr old bike is a bit ambitious but not impossible.

Sort a new ground cable 1st, fully charge Battery before testing, it's a total waste of time doing any testing with a sub standard battery & a known crappy ground.

Confirm you've a good fully charged battery, less than 12.8V, it's past its best, consider replacing it.

Always Test Batt voltage disconnected then connected, compare voltages, you may have gremlins at work or a parasitic drain.

Always test a charging system with head lights on full beam, stator needs a load on it, what are you seeing @ idle? & @ 5,000rpm?
Over 12v @ idle with headlights on dip is acceptable, around 14v @ 5,000rpm is good too, anything above or below R&R will likely be on it's way out.
These tests will show the health of the system.
Yamaha MT9's use a quality R&R if you can find a good used one.

I've also own a 5th Gen VFR800, these often get a rewire to bypass the bikes stator plug & wire the stator direct to R&R & R&R direct to battery, this can also be done with the Fazer if need be, losing the 3 pin plug above the carbs is no bad thing.
Note:
From experience, lots of these old Fazers were dealer fitted with a shitty Meta alarm & soldered into the loom, can be a real mare to remove & get loom back to stock, I've removed loads of em, mine's long since gone & loom all back to stock spec, all alarm systems are dog shit & cause no end of electrical gremlins, since you've not mentioned an alarm, I assume your bike's no alarm fitted?
If it does, get rid is my advice, along with all of its associated loom, you'll only end up pushing it home at some point.

[BSR67]

Thanks Gaz66 - all good advice. Interestingly th manual says to remove the stator. Which setting do I need to multimeter on - 200k?

I should double check the battery too - I've only relied on the bike charging system - so will put on charge.

The FH020A upgrade is tempting - it's not hard to do and I actually have a spare having upgraded my lad's GSR600 and carried a spare for him, plus wiring plug, whilst touring europe.

Thanks but absolutely no alarm thank heavens. My 5JJ R1 did exactly what you described - left me stranded. Luckily, a mate used to install alarms so for £50 he removed the nasty thing. Obvs insurer wanted a little more £££!!!!

Thanks

BSR67

[Gaz66]

Thanks Gaz66 - all good advice. Interestingly th manual says to remove the stator. Which setting do I need to multimeter on - 200k?

I should double check the battery too - I've only relied on the bike charging system - so will put on charge.

The FH020A upgrade is tempting - it's not hard to do and I actually have a spare having upgraded my lad's GSR600 and carried a spare for him, plus wiring plug, whilst touring europe.

Thanks but absolutely no alarm thank heavens. My 5JJ R1 did exactly what you described - left me stranded. Luckily, a mate used to install alarms so for £50 he removed the nasty thing. Obvs insurer wanted a little more £££!!!!

Thanks

BSR67

.................................

Depends which meter you have, always good to start in a high range, then bring down the settings till you see a measurable resistance.
Compare values with manual, if you don't have it downloaded, I can find it for you.

Don't forget any component under Ohms test must be disconnected from the bikes loom.

If your insurers make anything of not having an alarm fitted, they're morons & you're insured with the wrong company, alarms don't stop bike thieves, they just throw it in a van & away they go, a good lock & chain will stop 99% of thefts.