Suzuki GT380 timing.

pearljam724 · Post by **pearljam724** » Thu Jul 17, 2014 7:52 am

Glyn.G wrote:Oh Dear, Something must be wrong somewhere. I've set the BTDC to 2.1mm on the left cylinder using a Dial gauge and checked the position of the L mark on the propeller as suggested. It's a country mile off, at least 20 degrees past the mark on the casing. The L mark on the propeller actually lines up when the piston is at 4.5mm BTDC. Hence there is not enough adjustment on the backplate slots to set the points to just opening at 2.1mm BTDC.
Could I have put the clutch casing back on wrong ? I lined up the centre punch mark on the small gear with the pointer plate, then lined up the L mark with the rib on the casing and slipped the casing back on. All seemed well.
Do you think I should buy another gasket and have another go at lining everything up. How come the bike runs well if it's so far out, I'm at a loss.

That's the same exact outcome I had before the gauge. My left cylinder was far off as yours, the others were fine consistently after comparing the gauge and the propellers. You can get the timing close enough that the bike will easily start, idle great and run well on very flat ground. But, the timing is off far enough that it doesn't create enough power for descent inclines or it will drop cylinders after riding a few miles or more. Eventually having not the slightest power. Not even on flat ground. You'll think the bike is fine, allowing you to want to be adventurous and it will leave you stranded. This is another good reason to accurately do it with a dial. Piss on static timing. The way I see it, it should only be used in emergency situations. Suzuki pretty much says the exact same thing in the manual. " Only in an Emergency." But, as mentioned by others previously, if the bike passes all running tests with static timing. Then that's all that you would need. But, I wouldn't rely on it. The gauge is the way to go. It removes the inaccuracy of using the propellers. The first test anyone should perform, is run the bike up the nearest steep hill. Otherwise you can find out the hard way. It sucks to have a motorcycle towed home.

Glyn.G · Post by **Glyn.G** » Thu Jul 17, 2014 8:21 am

YAY ! Problem solved. I removed the casing and found the nylon timing gear was 1 tooth out. I set the left cylinder to 2.1mm BTDC and the punch mark on the crankshaft gear lined up with the indicator arm perfectly, then I set the L on the propeller to the rib on the casing, then carefully eased the casing back on. Now at 2.1mm BTDC everything lines up bang on. I thought it ran ok before but now it's pulling like a train.
Thanks for all your help with the technical stuff, couldn't have done it without you.
I've spent 40 years in engineering building 40 ton marine diesels but seems I haven't learnt anything. What a silly mistake to make.

pearljam724 · Post by **pearljam724** » Thu Jul 17, 2014 8:24 am

Run the bike up a long and steep incline. That will tell you if it's right.

yeadon_m · Post by **yeadon_m** » Thu Jul 17, 2014 10:53 am

PJ,

Just to share experiences on importance of ignition timing, I've had mine way out (either side of spec) and to be honest its not made a heap of difference. Not saying its not a good idea to have it spot on, it certainly is. But on some GTs, being low tuned motors, it seems not that sensitive an item and other things can matter as much or more.

Cheers,
Mike

pearljam724 · Post by **pearljam724** » Thu Jul 17, 2014 9:07 pm

From my experience. I know what you say is true, Mike. But, at the same time. That scenario would play out differently for some people depending on where they also live or ride. I live and ride in and around a lot of steep mountainous terrains. My bike simply refused to climb what I consider smaller hills where I live until the timing was spot on. Once it finally was via the gauge, it would climb very steep mountain summits with ease. There's no second guessing. My propellers were way off. Far enough to affect it making the proper amount of power when it needed it. If it didn't need to create a lot of pulling power it ran fine. Regardless, of the timing being far off. As you, stated.

Glyn.G · Post by **Glyn.G** » Mon Jul 28, 2014 3:52 am

Ah Well, back to the drawing board. After a week touring Ireland on my FZ1 I decided to give the 380 a run out around the Peak District. Got several miles into the ride and it started misfiring on the middle cylinder, so I managed to limp home.
I know the timing is now ok, and the points and condensers are new after market sets. How come it runs fine for a while then packs up. Cleaning the points with a contact cleaning spray eliminates the problem for a couple of miles then it packs up again. I'm at a total loss

.

jabcb · Post by **jabcb** » Mon Jul 28, 2014 6:32 am

The stock plug caps have resistors in them & can go bad.
When installing new caps, trim ~ 1/4" off of the HT lead to make sure you have a good connection.

Make sure you have good clean wiring harness connections between the coils & points.

Two ignition improvements worth considering: high-performance fine-wire spark plugs & better coils.

Two options for fine-wire spark plugs:
1) non-resistor plugs with resistor caps: NGK B8EGV plugs with LB05F caps
2) resistor plugs with non-resistor caps: NGK BR8EIX plugs with LZFH caps

Rex Caunt Racing has coils that will fit the stock coil mounts.
Make sure to get the coils with ~4 ohms primary resistance.
For more info see: viewtopic.php?f=29&t=4824

yeadon_m · Post by **yeadon_m** » Mon Jul 28, 2014 1:31 pm

Glyn,

I wonder if a set of points is sticking open. Suzuki bulletin #3 in here says it has been a dealer problem decades ago:

http://www.ozebook.com/compendium/techb ... %201-9.pdf" onclick="window.open(this.href);return false;

The issue can be that after 5-10miles, heat expansion causes the moving point to bind on the shaft. If so, easily fixed. And, testable by swapping a known good (used) set, if you have one.

Cheers,
Mike

Suzukidave · Post by **Suzukidave** » Mon Jul 28, 2014 1:46 pm

With this new problem has it always been the center cylinder that stops firing ? If you have a timing light that gets its trigger by clamping around the HT spark plug wire its a easy test to see if its getting spark or not when you have a problem .. no flash from the timing light = no spark .

JFISHSOLEVIBE · Post by **JFISHSOLEVIBE** » Mon Jul 28, 2014 10:34 pm

Super glad this topic came up!

After installing my newtronic ignition, I set the timing using the static marks. Bike runs pretty well, idles well, but I know I'm missing a bit of oomph in there. Really wanted to buy a dial gauge but they're crazy pricey. Anyone in the western Pennsylvania area by chance care to lend theirs out for a few days? I'd be forever grateful!

JFISHSOLEVIBE · Post by **JFISHSOLEVIBE** » Tue Jul 29, 2014 8:49 pm

Bit the bullet and ordered a dial indicator. Reading some of your responses on here has me really pumped. Something tells me the timing has been slightly off for some time and Ive just come to take it as 'normal'. Hearing that my 380 may one day soon 'pull like a train' is a very exciting idea!

Thanks for the encouragement as always guys ill let you know how it goes this weekend.

JFISHSOLEVIBE · Post by **JFISHSOLEVIBE** » Sun Aug 03, 2014 6:59 pm

Alright! Here's an update. Got my dial gauge, and times the L and R cylinder and they're bang on. Running better than ever.

Now here's the questin - when it comes to the middle cylinder, how does one use their dial gauge when the center bar of the frame is directly above the plug hole? Seems like a tricky spot
To do just about anything!

Thanks as always guys!

Suzukidave · Post by **Suzukidave** » Sun Aug 03, 2014 7:53 pm

How did the factory timing marks line up when exactly set with the dial gauge ? if L & R were on the factory marks i would wager the middle mark would be correct also .

yeadon_m · Post by **yeadon_m** » Mon Aug 04, 2014 3:23 am

On my GTs I have two gauges. A 0-5mm small one for the GT380 and a bigger 0-10mm one for the GT550 and 750. The small one easily fits under the frame on the centre, provided its slipped well down inside its plug adaptor!
Cheers,
Mike

yeadon_m · Post by **yeadon_m** » Mon Aug 04, 2014 3:29 am

Jabcb,

I just read your earlier post.

Two ignition improvements worth considering: high-performance fine-wire spark plugs & better coils.

Two options for fine-wire spark plugs:
1) non-resistor plugs with resistor caps: NGK B8EGV plugs with LB05F caps
2) resistor plugs with non-resistor caps: NGK BR8EIX plugs with LZFH caps

I wonder just how critical the resistor is. I just checked and my GT380B has new copper-cored (low resistance) plug wires (I fitted them), BR8EIX plugs and LB05F caps. It runs by far the best of all 6 GT triples I've ever owned. Should it not? As far as I can tell, the resistances alone or combined are still very small vs the resistance of an air gap across a a plug, so while I've read about resistance caps, wires, plugs etc I cannot square why it should matter (apart from electrical interference!).

Love to be educated on this, from any source.

Cheers,
Mike
ps: my GT750 has carbon plug leads which, after I'd installed them, I learned are also 'resistance wires'. That bike also has resistance plugs. The metal plug caps are stock and maybe they are also resistance type, in which case I have 3 resistances! that bike also runs well. All my problems there have been carb related.

Suzuki GT380 timing.

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