2018 ec300 squish

Cox76y

Member
So I finally got around to checking my squish. Im on my 8th plug now and have just changed to amsoil dominator to hopefully help me with a bike that is jetted fine but spooge city n keeps wrecking plugs. Anyway, I think the major culprit is my squish, which is at approx 2.1mm by my measurements.
Hopefully Ill get to send the head down to get cut soon but im not keen to have to take the barrell off to check crown height of the piston as suggested by someone else in this forum as there is supposed to be 2 different types of pistons getting used.
Is anyone aware if there is another way of finding out which piston was used without having to remove the cylinder?? Surely a record was kept somewhere along the production line.

thanks

JC
 
What oil are you running and what ratio? I am sure the squish will help a lot. Even with R50 (high flash point oil) in a bike with mediocre squish we get tons of spooge but we do not often foul plugs when the jetting is correct. I would either get the squish corrected or lean out the jetting slightly probably in the pilot or needle
 
You should be able to check the dome height with the piston at tdc and a flat edge laid across the top of the jug. Measure the clearance between at the middle and edge and take then away from eachother. Normal dome height is 3.7mm from memory.

Make sure you send them some really good samples too. Preferably with a single piece of solder. I sent 2 or 3 samples with some thinner strand twisted which they had trouble getting an accurate edge measurement on.. and I ended up having to send it back down for a re-work.

I also find it strange that you're fouling plugs. My first EC300 had something like 2.6mm clearance and while it was a pig to get running right, it never fouled a plug.
 
My bro had an 18 250. He eventually sold it as he couldnt get it jetted right: head cut, numerous jetting changes.The 4 people I know with '18 300's have all had theirs done...The 300's all worked fine without the head work but seem much better with it. None fouled a plug though- the issue was spooge
Fouling plugs seems a rich issue. Maybe post up what jetting you're running and in what environmental conditions.
Most will say the head work is the best money to spend. I've had a fair number of 300 and 250 2T's and I never felt the need too- jetting seemed to make them perfectly serviceable. Maybe I was just lucky!
 
As Zman said...What Oil and Ratio are you using?

What is your jetting?

Is float height good?

As other's have mentioned, a big squish clearance or low compression ratio may reduce the performance a bit, but it shouldn't cause you to be fouling plugs.

I think your problem is elsewhere.
 
When the jetting is off, let's say rich, and this can be at one particular throttle position, indeed you could be lean on pilot near closed, rich on needle near mid throttle and lean again on main. Just saying think about where.

Anyhoo, if you are rich, say just open as the needle is too thin there and you are getting wet drops of fuel, combustion will be incomplete and unburnt fuel will be expelled out the pipe. If you run oil in your fuel the residue will contain, wait for it. .,oil.

Running less oil seems like a good idea but will make the fuel to air mixture richer. Meaning bad combustion if it was already rich.

My bike seems to start running a bit burbly after a year or two and I remember that I should really change the plug. Never fouled one.
 
Have you told her you'll change yet?

That should buy you another week or so.
Until the courier turns up while you are out .
 
Spooge

I have 2011 bikes my bikes Evan jetted good still had spooge so I went to the fmf power core 2 the smaller silencer not much spooge now hope that helps
 
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