Crazymac680 Posted October 20, 2019 Report Share Posted October 20, 2019 Hi. I'm trying to find the stock squish on the above bike. I have a book for the 2010 Evo book but that gives a measurement for the top of the piston to the cylinder. This doesn't seem right for my bike as it would give my 4.5mm squish. Thanks for any help. Quote Link to comment Share on other sites More sharing options...
lineaway Posted October 20, 2019 Report Share Posted October 20, 2019 Probably lost in translation. Huge difference to the top of the head vs the cylinder. Quote Link to comment Share on other sites More sharing options...
mcman56 Posted October 21, 2019 Report Share Posted October 21, 2019 Standard factory recommendations seem to be 1 to 1.5mm Quote Link to comment Share on other sites More sharing options...
dan williams Posted October 21, 2019 Report Share Posted October 21, 2019 This might be a dumb question but why bother? Are you trying to change engine characteristics? Is this a complete rebuild? Quote Link to comment Share on other sites More sharing options...
djr Posted October 22, 2019 Report Share Posted October 22, 2019 22 hours ago, dan williams said: This might be a dumb question but why bother? Are you trying to change engine characteristics? Is this a complete rebuild? you would bother if you want the best engine performance, I didn't think it was important until I set the clearance correctly on a 175 Yamaha , and found a noticeable improvement in power , plus it stopped pinging ( which had been a problem previously } Quote Link to comment Share on other sites More sharing options...
lineaway Posted October 23, 2019 Report Share Posted October 23, 2019 Pinging is just jetting and/or fuel issues. All the rev 3`s ran great with a little attention. Squish was not an issue unless at high elevation. Quote Link to comment Share on other sites More sharing options...
faussy Posted October 23, 2019 Report Share Posted October 23, 2019 On 10/21/2019 at 5:38 PM, dan williams said: This might be a dumb question but why bother? Are you trying to change engine characteristics? Is this a complete rebuild? He has measured his squish at 4.5mm. He should definitely bother Quote Link to comment Share on other sites More sharing options...
Crazymac680 Posted October 24, 2019 Author Report Share Posted October 24, 2019 Thanks guys. I gave up on the top of piston to top of cylinder measurement. A face book user thinks that measurement was for a flat piston while mine is dome shaped. Once I stopped trying to change gaskets, to chase that measurement. I installed everything stock and measured squish at 1.8mm. As I'd just spent the night researching squish. This seems like a safe distance to start with. Most of the research I did, stated that Between 1 at 2mm would be your tuning zone. Under 1 would be dangerous as my piston expand up 0.7mm when hot. It's a shame beta don't have a book measurement to remove any confusion. Quote Link to comment Share on other sites More sharing options...
Crazymac680 Posted October 24, 2019 Author Report Share Posted October 24, 2019 This was a new bike to me that blew after 4 hours, following a full rebuild by the previous owner. I'm just trying to make sure everything is back to stock so this doesn't happen again Quote Link to comment Share on other sites More sharing options...
2stroke4stroke Posted October 24, 2019 Report Share Posted October 24, 2019 (edited) 3 hours ago, Crazymac680 said: Thanks guys. I gave up on the top of piston to top of cylinder measurement. A face book user thinks that measurement was for a flat piston while mine is dome shaped. Once I stopped trying to change gaskets, to chase that measurement. I installed everything stock and measured squish at 1.8mm. As I'd just spent the night researching squish. This seems like a safe distance to start with. Most of the research I did, stated that Between 1 at 2mm would be your tuning zone. Under 1 would be dangerous as my piston expand up 0.7mm when hot. It's a shame beta don't have a book measurement to remove any confusion. Beta don't even have a book measurement for ignition timing, so are unlikely to see squish as an important piece of information. Edited October 24, 2019 by 2stroke4stroke Quote Link to comment Share on other sites More sharing options...
lineaway Posted October 24, 2019 Report Share Posted October 24, 2019 From the sounds of it, I would be more concerned about the water pump and fan. Was it a full rebuild with mains, seals, and rod? Quote Link to comment Share on other sites More sharing options...
Crazymac680 Posted October 24, 2019 Author Report Share Posted October 24, 2019 The water pump had loads of in and out play. Impeller was very worn. I replaced the bearing, seal, impeller and gasket. The in and out play is gone now. Thanks Quote Link to comment Share on other sites More sharing options...
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