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squish problem i think !!!

Posted:
Sun Aug 17, 2014 1:52 pm
by lcs99
Had a blown base gasket, Easy job!!!.
Put it all back together kicked it over and the piston was touching the head, So measured the thickness of the base gasket and the new one was thinner approx .7 of a mm. Got a 1mm base gasket put it all back together again and now it will not tick over, it starts and rides ok but just dies on tick over, if the squish was not right and over 1.5 would that make it not tick over? my friends took his digital measuring tool back at the moment so I cannot get a check measurement.?
Re: squish problem i think !!!

Posted:
Mon Aug 18, 2014 12:07 pm
by foremanbob
So what is your squish measurement at present. Squish would have to be huge to cause an issue?
Have you checked for leaks? there's a couple of links on here where you can see how to make an easy leak tester from an old innertube.... just search....
Re: squish problem i think !!!

Posted:
Mon Aug 18, 2014 1:48 pm
by Adam_Winstone
I doubt that squish is the issue. Many standard factory engines have way over the commonly recommended 1 to 1.5mm and they run fine and have no issues with tick overs. I imagine that this is either an assembly issue or something to do with adjustment of settings, most likely carb adjustment.
Adam
Re: squish problem i think !!!

Posted:
Mon Aug 18, 2014 1:49 pm
by Dimitrios_231
I have measured standard engines that were working fine for years,
most of them had more than 2mm squish.
Did you remove the piston?
Does the piston arrow facing the exhaust post?
Re: squish problem i think !!!

Posted:
Mon Aug 18, 2014 1:50 pm
by Dimitrios_231
OOooops Adam was faster

Re: squish problem i think !!!

Posted:
Mon Aug 18, 2014 5:14 pm
by lcs99
Right piston is in the right way, I changed the carb just to see if there was a problem with it, I turned the carb right on full adjustment with no difference, just will on tick over. Squish is 1.5 at the moment?
Re: squish problem i think !!!

Posted:
Mon Aug 18, 2014 5:40 pm
by Adam_Winstone
Not a squish issue then.
Re: squish problem i think !!!

Posted:
Mon Aug 18, 2014 6:01 pm
by Scooter Paul
Adam_Winstone wrote:Not a squish issue then.
If it's not just a carb adjustment solution that's required I 'm thinking maybe a dreaded air leak especially as you've replaced the base gasket.
Paul
Re: squish problem i think !!!

Posted:
Tue Aug 19, 2014 6:01 am
by lcs99
yes Paul ,think your right a air leak somewhere.

Re: squish problem i think !!!

Posted:
Wed Aug 20, 2014 5:29 am
by Bettagetabrettabolti
Definitely an air leak - if you have a rubber mounted carb probably best change the rubber sleeve as these can crack and split! Bolti
Re: squish problem i think !!!

Posted:
Wed Aug 20, 2014 7:36 am
by MickYork
Is the timing too for retarded ? doesn't explain why it worked before but worth checking.
Re: squish problem i think !!!

Posted:
Wed Aug 20, 2014 7:38 am
by coaster
It is also possible that the choke is sticking on slightly, make sure it is operating correctly, you need a little slack (not too much) in the cable when it's off. Otherwise I'm with the air leak school of thought
