head was warped.
My machinist has skim the head around 0,5mm.
After this there was no edge round the combustion chamber an the squish was to less (~0,6mm).
i am told him that the squish band must recessed into the head by 0.4mm and angled at 15 degrees.
I thought a squish clearance around 1mm is safe.
today he has finished the work.
ok at home i measure the diameter from the combustion chamber (edge to edge).
The diameter is exactly 56mm. Shocked
the piston has 55,6mm.
my old destroyed head has an combustion camber diameter from ~57,5mm !!
ok my questions.
why is the diameter from the standard head combustion chamber much bigger then the cylinder bore diameter?
can i use the head with 56mm?
the head skim was 0,5mm.
to much compression now?
ok i know... many questions and perhaps some stupid questions.
I have a new crank, new coated cylinders and new pistons.
i have no interest to destroy the engine with a bad cylinder head....
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Re: cylinder head skim
From my understanding, the combustion area of the head should have a diameter that is the same as the cylinder i.e. 56mm.
If you took 0.5mm from a standard head, your squish would PROBABLY be Ok, however, you need to measure this. Its quite easy, poke a piece of solder wire in to the cylinder via the spark plug hole and trap it between the piston and the head by gently turning the engine over with the kickstarter by hand. Remove the squashed solder wire and measure with a set of vernier calipers. 0.8mm is about right and as Elf said, anything below this is getting a bit close. Do this for the front, back and left and right of each cylinder. Reducing the squish only has only a moderate effect on the compression ratio and does not require higher octane fule. I did this for mine and it was fine - so you 'should' be Ok.
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sounds like the head gasket to me
problem with all the r range of yamaha
you have to drop the engine out to do anything really
but before you do that run a compression check on all 4 cylinders
if the compression is low on 1 or more cylinders
it could be either your head warped (not so bad)
or worst case a cracked liner (barrel)
you can get the head gasket on ebay for around $40
but the main cost can depends
on whether you have overheated the engine or not
if it has overheated it can warp your head
then the head has to be run to an engineering shop
and have it skimmed
if it is a cracked liner get a second hand engine
but if you have not overheated the engine
just replace the head gasket
but personally i would still have the head checked out for cracks
Hi Anonymous, popping, coughing, spitting, or backfiring through the carburator is usually caused by air getting sucked in combustion chamber do bad intake seals leaking. Leaking exhaust gaskets can also be suspect. Remove air cleaner and backing plate, while engine is idling spray WD-40 or Brake Kleen around intake manifold to head area, if RPM's increase you have an intake leak and seals need to be replaced, also spark plugs will be burning whiter than normal. Good luck
Hi Anonymous, popping, coughing, spitting, or backfiring through the carburator or induction module is usually caused by air getting sucked in combustion chamber do bad intake seals leaking. Leaking exhaust gaskets can also be suspect. Remove air cleaner and backing plate, while engine is idling spray WD-40 or Brake Kleen around intake manifold to head area, if RPM's increase you have an intake leak and seals need to be replaced, also spark plugs will be burning whiter than normal. Good luck
Hi Anonymous, popping, coughing, spitting, or backfiring through the carburator or induction module can be caused by air getting sucked in combustion chamber do bad intake seals leaking. Leaking exhaust gaskets can also be suspect. Remove air cleaner and backing plate, while engine is idling spray WD-40 or Brake Kleen around intake manifold to head area, if RPM's increase you have an intake leak and seals need to be replaced, also spark plugs will be burning whiter than normal. Good luck and have nice day.
It sounds like you have a crack in the Cylinder Head or worn valve guides that allow oil into the combustion chamber. If you start the bike and check that all the exhaust pipes are heating up at the front of the cylinder block you can make sure it's running on all cylinders.( Just spit on your finger and a quick dab on each pipe will tell you!) If it isn't then it's more likely the head is cracked or head gasket blown. I accept no resposibility for burnt fingers. Safe Riding!
Stop running the bike immediately....And start pulling the head off so the valves can be checked and adjusted. If the valve is out of spec it can wear down the clearance needed and cause major engine damage, usually breaking the valve off into the combustion chamber and destroying that cylinder, head, and piston. Also make sure that your oil lines up to your head aren't clogged, this will end in your motor seizing. Good luck.
That would be my guess. Could also be a warped head. White smoke usually means that you are getting water (coolant) into the combustion chamber, so steam (water vapor) is coming out the exhaust.
I would pull the head, examine the gasket for signs of damage, have the head checked for cracks and flatness (no warp). If the head is damaged, repair or replace it. If there is no visible damage to the head or gasket, check the block carefully. If no damage, then put a new gasket in it and put it all back together.
sounds like a blown rocker cover gasket,its quite common,although you may have a warped rocker cover thats quite common on Harleys as well,order a new gasket,which you'll need anyway,while you've got the rocker cover off check for warp with a straight edge.if the cover is warped order a new one, Harley were recalling a few bikes not long ago to replace the same thing,but l think they were around 04-05 sporties cant be sure.