2018 GP300 not starting / breaking kickstarters

Undertow said:
- After putting the plug back the engine gets hard to turn right away.
Click to expand...

So based on that, the engine becomes very difficult to rotate as soon as you fit the spark plug...then it's pointing to high compression ratio.

As Neil E has suggested, it would be a good idea to measure your squish clearance, it's quite easy to do.

As I said before, if for some strange reason your compression ratio is very high/too high then I wouldn't run the engine as there's a risk of damaging your nice, shiny, new crank.

Good luck, Dave.
 
Have you checked the piston position at TDC? This is normally set by using different thicknesses of base gasket to adjust the cylinder height.

I would take the head off to check. It only takes a few minutes.
 
By the way...is the compression vent hole only on later models? I don't remember seeing it when I fitted a new piston kit on my 2004 model.

14 years old and still going strong!
 
I truly tried to kick with that old (fixed) lever and got up to 209 (14,4 bar). I guess this is as far it looks to go. I guess this is not hugely high? But just to be able to learn I?ll do the squish / head check. Unfortunately have to travel for the next two weeks so it?ll take some time to do it.

At the same time I can check the vent hole.

Thank?s for the help so far, we?ll get on top of this 👍
 
So a short update...

Didn't go on the trip, don't ask :(

So had the time to do the bike :)

Did the squish. Seems to be around 1.5 mm. The measurement on the solder was 1.55 - 1.6 mm, but it was 1 mm line and had to twist it a couple of times. So I guess it may have some elasticity more than plain solder.

But anyway, not really bad squish I guess, and everything else seemed to be ok also. Without the head the engine turns nicely when pressing the kicker. Not binding anywhere.

And there was also the vent hole, a tiny hole in a nice new cylinder :eek:

And also swapped a new needle (NEDW), so had a productive weekend.

Well, guess what. After some kicks the new lever is giving signs of giving up! The reason? The bike kicks back twice as hard if it doesn't start.

Just came back from garage after having an idea of removing the spark plug cap and kicking the bike without it. And it doesn't kick back. So now I'm leaning towards ignition timing as Davehuge suggested. And this would make sense also from the running point of view. By this I mean that the engine is really happy to stall at low rpm and is still running kind of rough even with the new needle, which improved the situation anyway.

But how to check the timing? I'm an mechanical engineer, electricity is something of a mystery to me :confused:
 
Undertow said:
Did the squish. Seems to be around 1.5 mm. The measurement on the solder was 1.55 - 1.6 mm, but it was 1 mm line and had to twist it a couple of times. So I guess it may have some elasticity more than plain solder.


But how to check the timing? I'm an mechanical engineer, electricity is something of a mystery to me :confused:
Click to expand...

The squish is pretty tight for a stock setup.. thus compression ratio will probably be on the high side.

Ignition timing wise I'd start by pulling the flywheel cover, flywheel and making sure the woodruff key is still in place and not sheered off (or missing).
 
The flywheel is pushed onto the taper of the crank, then secured with a nut. it's position is set by the Woodruff Key to give the correct ignition timing.

If the Woodruff key has sheared or is missing, the flywheel could have rotated on the crank, giving the wrong ignition timing.

To remove the flywheel from the crank you'll need a flywheel puller/extractor, don't try and use anything else or you could damage the crank/flywheel.

Below is the part number for the genuine GasGas puller, but there's many aftermarket pullers available that will work fine, just make sure it's the correct thread, on the older GasGas EC300 it was a M27x1 Left Hand Thread, on the later models I think it's an M27x1 Right Hand Thread, can anyone confirm this is correct?

Key.JPG

Part number for Flywheel Puller/Extractor
Part Num.JPG

Flywheel Puller/Extractor
Puller.jpg
 
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Ok. That?s straight forward enough. Now just have to find the right hand 27x1 mm puller. In the picture the thread is right hand and I have also read that in new engines the thread is right hand. Correct???

Also gave message to importer. He is trying to get me new CDI, just in case the program is not ok (should be the revised version straight from the factory but you never know).
 
The 2018 workshop manual warns that the flywheel nut has a left hand thread but there is no such warning for using the flywheel puller.
 
I had similar problems with my not 2018 (it's a 2014 actually) EC250, turned out to be just a cracked/loose wire in the loom right under the steering lock. So I'd give it a look there.
 
Confirmed and tested cause I have both.
Until 13' models you need M27x1 left hand thread puller but from 14' model on you need M27x1 right hand thread puller like the trials bikes.
 
SpirosZ1000 said:
Confirmed and tested cause I have both.
Until 13' models you need M27x1 left hand thread puller but from 14' model on you need M27x1 right hand thread puller like the trials bikes.
Click to expand...

That's great information, thanks for confirming. :)

So Undertow, for your 2018 model, nut securing the flywheel is Left Hand Thread and Flywheel Puller is M27x1 Right Hand Thread.
 
Last edited:
Thank?s for great info SpinosZ1000 and Davehuge.

Was a pit PITA to find one, but enduropuro.it saved me again. The bad part is, that when browsing through the website it is so difficult to just order one flywheel puller... :rolleyes:
 
What about eBay? There's plenty for sale on eBay and the prices are very good. Surely they will ship to Finland?

I use eBay all the time, love it! :)

Try this link to eBay UK...just be aware this search will list both LH and RH thread pullers...

https://www.ebay.co.uk/sch/i.html?_from=R40&_sacat=0&_sop=15&_nkw=m27x1.0+puller&rt=nc&LH_PrefLoc=3


Or try this link to eBay Germany...be aware it also lists LH and RH thread pullers...

https://www.ebay.de/sch/i.html?_from=R40&_sacat=0&_sop=15&_nkw=m27x1+polrad&rt=nc&LH_PrefLoc=1
 
Thanks for that, I knew about gasgasuk.com but that's the first time I've seen trialendurodirect.com, looks good. :)
 
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