Moto Guzzi 1200 / starting issues

[Lobo]

Hi all, possibly one for Mick / Green1 - but welcome all thoughts.

Have a 2011 Griso 1200SE, which has only got about 3500 dry miles on it. Never seen a dealer whilst in my possession, and probably not since it’s 1st service.

Anyways, it’s a momentary-press starter button, which then cranks the motor as much as necessary. Previously this’d be a couple of seconds.... now it’s a full crank cycle of about 5 secs ... after which it aborts. 2nd attempt sometimes catches, 3 attempts and it’ll catch and keep running... for now. After this it’ll run a bit lumpy for the first mile.

I’ve tightened all the manifold and exhaust clamps, which has cured a pop on the overrun. I’ve put injector cleaner through the tank, and only ever use the highest octane / quality fuel avail.

It’s had new plugs recently; and the tappets adjusted iaw the manual.

MotoGuzzi dealers very thin on the ground here in Bris; by and large I’m not a fan of dealerships / garages unless personally recommended.

Anyhoos folks; thoughts please?

Ta,
Simon

[cooleronthecoast]

I used to have a 1200 Sport which did exactly the same thing. The big block Guzzis always struggled to meet emissions regs so the factory sent them out running very lean.  In the end they couldn't meet the likes of Euro4 at all hence they got dropped from the line up, or that engine did anyway.You can get a unit made by Finebau Forge in the UK which will smooth out the lumpy running at low rpm.    Have a look here :  http://www.guzziriders.org/finebau-forge-tuning-unit_topic5867.html
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[K2-K6]

If not checked recently,  make sure plug gap is set to the minimum of given tolerance for your bike.

When it has started,  feel for temperature in the main battery cables, earth and pos.  Plus the lead from solenoid to stater motor if they are remote from each other.  Most factory fit leads aren't that generous in capacity and raise current draw noticeably.

Starting mixture should be ok as efi systems modulate this based on temp sensor and it's not usually part of emmisions testing,  so should be no barrier to initial firing. Saying that,  you'd normally check the sensor itself by measurement of its resistance changing in response to input temp if you think it's suspect.  It just reports a gradient of resistance to the ecu which is used to alter mapping away from normal temp running while it needs richer starting.

[Lobo]

...thanks gents, just to be clear the bike used to start ‘on the button’.... K2 this would not support the increasing starter motor draw as the issue - as I see it.

Interesting forum page Cooler... will investigate this avenue later.

I’ll pull the temp sensor and check whether it’s resistance changes with temperature.

My gut feeling is dirty / gummed injectors... tho tbh I’ve little experience is such areas.
Are these easy to service / clean?

Keep the thoughts coming all.

Ta,
Simon

[SumpMagnet]

Last Guzzi I owned was a LeMans 850 MkIII ....  but I did a lot of research on these as I intended to buy a Griso.... until I read about the issues with the 4 valve heads and the tappet blocks self destructing. Aprilia never took responsibility for the problem, and it can manifest at low mileage.

Have you had any issues?

Guzzi only cured it by fitting roller tappets...and that was late in 2012

[Green1]

Hi Simon

My Guzzi has been great since I stripped every single connection I could find on it. Almost everything had gone green 
Its now covered about 11000 miles but looks more like 50000 miles  . You need to get some more miles on it Simon mine now runs lovely so much smoother as its just starting to think about running in

Mine did the same thing about 5000miles ago. On the Sport I pulled the yellow wire from the starter relay plug under the seat. The starter relay is the smaller one. Run a fresh feed from the battery with a 15amp inline fuse to the now free pin in the plug.
Tape the now redundunt yellow wire up and tuck it out of the way.
I have also run a larger wire from the battery to alternator.
I think the slightest voltage drop and they abort there start up procedure so a perfect battery and clean electrical contacts are a must.
I have been told If it repeateadly blows the new 15amp fuse its normally caused by the starter selanoid sticking as there filled with grease by the manufacturer and it goes hard over time.

Almost forgot the Tappet mod is a must on the 4 valver

Mick

[Lobo]

Thanks Mick, Sump Magnet.

Yea, I too have read about the issues with tappets (a long while since), but recall being happy / convinced that the problem had been sorted < my engine # and not applicable. So far, no probs here... and not expecting any!

Within a short while of ownership it started blowing starter fuses, and yep Mick, have now modded the start Circuit wiring - though not run any new alternator wires. Specifically why did you do this??

Today I re-affirmed no ECU Fault Codes, and had the tank off / all electrical plugs apart and cleaned. (none dirty - it’s a coddled machine!). I checked the resistances of the Engine Air Temp Sensor AND the Intake Air Sensor... both spot on iaw the book. I also checked / set the plug gaps (to min) as suggested by K2-K6.

The battery is indeed old, but a LiFe from which I expect at least 2x conventional battery life. It cranks strongly, and leaves me in little doubt it’s ok. This said, I’ve a new car battery lying around, and outta interest may just hook it up tomorrow as most avenues now exhausted.

Cooler on the Coast suggested some mod to improve low rpm lumpiness.... it’s the starting issue I really want sorting; defo not bad, but nothing like the quick-fire up I enjoyed when it was new(ish).

To recap: from cold it cranks quickly and strongly for approx 5 secs, with possibly a fire. 2nd attempt... longish strong crank... catches, runs for 2 secs and then suffers something like a lean cut. 3rd attemp... strong crank... catches and runs lumpy for 10 secs before settling. If you touch the throttle in this time it’ll stall.

Thanks chaps,
Simon

[SumpMagnet]

Does sound more fuel than ignition related from that last post.....

The LeMans I had was a fussy starter when things were not 'just so' but that was cured by replacing most of the wiring and switchgear....and of course...it had hte old sticking starter motort brush thing. I had my strip and replace time down to 15 minutes.....but the modern Guzzis are a lot better in that regard. Only bike I know where the kill switch being 'off' still allowed the starter motor to crank.

The swapped lead from alternator to battery would potentially lower resistance and give a better charging voltage....larger wire gives less resistance...so for a given current, lower resistance gives more voltage. If the stock wire is marginal...it might make quite a difference, especially under heavy loads.

[Green1]

When mine was having starting issues the on board volt meter was reading 11.2v and it would crank over fast but refuse to start first and second attempt. Sometimes it wouldn't crank at all the first time and just click.
I replaced all the fuses in the fuse box even though they looked OK and I gained 0.1v after cleaning every conection I gained a bit more and it was starting a bit better but still very temperamental I was reluctant to change the battery as I was convinced it was good. It drove me mad in the end so changed the battery out of desperation and then got 11.6v before firing it up.
Before all the Mods I was getting 11.2v before starting and 12.5v when running.
After adding the larger alternator wire I now get 11.6v before starting and 13.3v when running.

I found the low rpm lumpiness has now disappeared. I assume the fresh battery and alternator mod combined with more miles on the clock has contributed.

My Guzzi used too shake the handle bars at tick over and blur the mirrors but it has now lost that.
 

Mick

[Green1]

Forgot to add the bike has now stood for just over 2 months now and I have just been out to the garage and it fired up faster then I could take my thumb of the starter. 

[Lobo]

... put a healthy car battery (on jump leads) in parallel to the bike’s battery today - no improvement in the starting woes. On board battery (alone) at 13.1v on either multimeter or bike display. Drops to abouts 10.5v during cranking. I also tried a voltmeter across (1) battery -ve and frame ... & (2) across battery +ve and starter motor +ve; the voltage difference on both tests about 0.2v during cranking ... which seems pretty ok. (0.5 and more might point to high resistance leads?)

A BIG downside to this thread was Sumpmagnet’s input 😂😂😂 - as I now believe my bike indeed has potentially bad tappets... which, whilst not a big job (3 hrs?) is big money... £800 or so. Bloody ouch. Info very hazy out there... my engine number leads me to believe all’s well, though the build year doesn’t. I therefore lifted the tappet covers and compared photos.... you’ve guessed it. Never a dull moment eh?

[Green1]

Out of curiosity just checked mine when cranking and I get 8.5v very briefly then straight up to 13.4v so I should think yours is getting plenty of juice.

Just a thought simon does your bike have the origanal plastic fuel filter inside the tank.
Its a well known issue as the body expands and the filter disintegrates causing fuel starvation.

[Lobo]

Hi Mick,

Interesting thought... and dunno. That said, once we’re beyond first start of the day it behaves beautifully and will redline iaw with my underwear. Ie I cannot imaging fuel starvation as the issue....

[K2-K6]

You could try a routine of turning it on,  but not cranking it,  leaving it on for five seconds, then off again.

Do this three of four times as it should be priming the injector circuit ready to start.  There's a pressure relief valve that dumps excessive fuel pressure back to the tank to give on aim psi at the injectors, this is controlled (usually)  by manifold vacuum to fine tune demand against engine load.  Anything "lazy" in that loop could result in lowered or raised psi which may affect the start.

You're trying to see if it then fires straight away on the "fifth" cycle to see if it changes anything.

[SumpMagnet]

Sorry Lobo .... me and my big mouth ...