Check your engines cranking pressure

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consider the fact that a head with a squish band presents a big "step" for the upwardly mobile intake charge, much more than any small amount that you are referring to.
But yes you can just as easily shave the cylinder down. Either way works.

Let me mention that the head temperature test has to be with the normal rider on the bike going at full speed. Some brain dead people on this forum think they can use their infrared heat guns to test their head while reving the engine with the clutch in. That is a no load situation which produces less heat.
 
Either way works. What we want is the way that works best. That would be the proper way. Have you done any modifications adjusting squish clearances to a engine using the after market heads shown below? If so tell us how much needs to be removed, and how far the diameter is reduced on the chamber causing it to encroach into the cylinder. Is this encroachment desired in a performance mod? Are you just talking crap about something that you have never tried yourself? If the answer is yes to any but the last question I'm interested. If it is only the last than you are waisting our time with unfounded opinions.View media item 60551View media item 60274
 
that's a point well made. If the squish area starts right at the mating surface then of course you don't want to modify it by shaving down the head. In that case you'd want to shave down the cylinder top.
 
jaguar said:
consider the fact that a head with a squish band presents a big "step" for the upwardly mobile intake charge, much more than any small amount that you are referring to.
But yes you can just as easily shave the cylinder down. Either way works.

Let me mention that the head temperature test has to be with the normal rider on the bike going at full speed. Some brain dead people on this forum think they can use their infrared heat guns to test their head while reving the engine with the clutch in. That is a no load situation which produces less heat.
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Jag you make to many assumptions my heat check is static!After a full out run Im not about to hold my sensor while riding! And as I said the heat radiates outward when just shut off and checked the plug base temp right away is close to the same but then 30 sec latter its cooler than the matting surface between cylinder and the head!I do this after a full speed run to see that the engine over all temp does not exceed 265-285 f if its above 285 then I look at how to lower it!You can see that the plug temp drops at the plug base quickly!And why would anyone rev an engine no load and no air flow what would that achive.
 
The normal only way to check head temp is while riding, which as you said is impossible with the infrared gun. (I have one too but don't use it for this.) To do it right you have to have the under-the-plug sensor with the readout where you can easily see it while riding. Who knows how much the head cools off in the 15 seconds it takes you to slow down, stop, get off the bike, grab the infrared gun, and aim it at the head?
 
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jaguar said:
Your system may work for you but the normal way to do it is while riding, which as you said is impossible with the infrared gun. (I have one too but don't use it for this.) To do it right you have to have the under-the-plug sensor with the readout where you can easily see it while riding. Who knows how much the head cools off in the 15 seconds it takes you to slow down, stop, get off the bike, grab the infrared gun, and aim it at the head?
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My way is just that and works great for me!For the video above my buddy was standing there with the camera and the sensor so only a few seconds past like I said that's why the first read at plug base was close!When setting up a engine i take it with me and do the same thing as a plug chop run full out for a while kill the engine without letting off the throttle stop and take a reading no time really to cool and gives me very accurate indacation of what it needs!The whole point to this was that that engines runs at 190 psi and spins up to 11,000 with no issues in the cylinder and not over heated!I'm not about to put a TTO gage on every bike I work on or build so the hand held gives me a real indicator to go by!
 
man I'm glad I live in a world where the laws of physics work, unlike your fantasy world. Mens happiness is often linked to the amount of fantasy in their life so I'll stop right now, I'd hate to rob you of your happiness.
 
Nah, I hate to see happy fools, so...
1) you have no f***ing idea what your engines peak temperature is and yet you assure me its not too much. Your method is super faulty! Only the area closest to the center of the head gets really hot and that starts to dissipate IMMEDIATELY after you turn off the engine. Stupid f***ing hillbillies. If I was god I'd invent a new law where when people reach a certain level of stupidity that they gag on it, not enough to die but enough to learn a lesson. People like you should not have the common right of being able to express yourself lest your stupidity infects others. I don't know why the moderators of this forum allow people like you to write anything. This reminds me of the moped army forum which has the craziest people in it. Anytime anyone with a voice of reason comes along they get attacked by a pack of rabid humans, as if they can't stand the presence of logic.
2) you don't need a TTO temperature gauge on every maladjusted bike you sell. Just buy one for yourself to see for yourself what your stupidity is doing to those poor engines.
3) you say the high pressure and high RPM does no damage. Yeah for the few runs you take them on they're probably just fine. But I garan-damn-tee you they are not reliable.
4) the great Gordon Jennings wrote that 175psi is the limit for reliability. But he was talking about regular motorcycles with good cylinders and CDIs, which these chinese engines don't have. On these the cylinder plating flakes off from high pressure and the CDIs were made for 4 strokes and they advance the ignition too much which drastically increases the peak pressure in the cylinder.

For every one but Sleazy Rider, please forgive me for this rabid rant. It's just that this guy who wants to replace knowledge with stupidity is driving me to lose all control. I'm not normally like this. To normal people I'm courteous. To ignorant hillbilies who have the audacity to open their big fat ugly pie-holes to spew out nonsense I just pull out the nukes.
 
gordon jennings did write that 175 PSI is the limit for good reliability, but he wrote that in 1973. even china is better at chrome plating today than we were back then.
 
Tough to read, but interesting as hell. He was probably waiting in a gas line when he wrote it.
 
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