yeah im not riding it untill i get this solved, i am also leaning towards a bad bore job.. i got the motor put together at a great shop but they send out jugs to be bored so who knows who could have done it..
weird noise, rings catching exhaust port..
- Thread starter super noober
- Start date
yeah im not riding it untill i get this solved, i am also leaning towards a bad bore job.. i got the motor put together at a great shop but they send out jugs to be bored so who knows who could have done it..
find a good machine shop or a v8 speedshop, i took mine to a local speedshop they were very nice and fast but it cost me 70 bucks for a bore. 100% worth it tho to kno its done right
its flotek ported but i had a fresh bore put on it before i installed it, im thinkin whoever did the bore is to blame for some shoddy work but i need to get it off and take a look.
ok i got the topend pulled and i see a few odd things, first the crosshatching seems to be worn off only on the exhaust and intake sides (front back if you prefer lol) but still visible on the sides. also if i push the rings out in the same direction one is definately a little bigger than the other one.. is that normal? but they are not stickie and i dont feel a nasty ridge on the exhaust port where its catching. thoughts anyone?
from what you described i would say your bore is out of round, or your piston is out of round, either way you have some superman hearing to hear it before it pops, while its apart a temporary solution could be to install some new rings. but i cant offer any solid advice for ya. hopefully you make out okay
i'd suggest sending ken oconnor a pm, with a link to this thread and that video, even though he isnt the builder of this, he's still a blaster forum bro, and will be more than willing and able to help ya out, more than likely he'll know just what the problem is,
he's usually on in the early mornings
matter of fact i'll send him this link and get him on the case for ya
he's usually on in the early mornings
matter of fact i'll send him this link and get him on the case for ya
haha thanks, like ive said i know my machine and i heard the noise immediately, everone else was like "i dont hear anything". i wish flotek or ken oconnor would chime in.
yeah it is nice to hear from those guys when you are stuck. it is like a sigh of relief to get an answer you know you can trust. not to say that any of you other guys don't know your s#%!
in the morning call ken up i bet he will give you some advice. the number should be on his website, he always answers when i call even on a sunday.
thanks man I:I, yeah im really thinking i got a good ole sh*t bore job.. X( i loooooove this cylinder and the power it makes so hopefully i can get it fixed.
That sounds like when i pull out of the old lady! JK For sure don't sound right, I just had my exhaust off for the twelveth time and tried to hear that sound- it isn't there. Just the compression sound. Maybe it is a Bad bore and the rings are not worn enough to cause any problems yet. Sounds to me as if they are maybe spreading out then snappin in place again. Good catch! I'll be watch this thread for some knowledge...
Wiseco makes up to a 68.25 piston, that is 2.25 over. But if you have it .70 over now you can get a 67mm piston that is 1.00 over. The .70 over with the 3mm stroker gives you a 210cc, the 1.00 over gives you a 213cc, and the 2.25 over gives you a 220cc. dejvu
http://www.wiseco.com/Catalogs/Power.../YamahaATV.pdf
http://www.wiseco.com/Catalogs/Power.../YamahaATV.pdf
Very strange sound but definitely ring / piston / port related. First I'll address some of the concerns.
1.Pistons are not straight. The top ( where the rings go ) is smaller in diameter than the bottom skirt. The largest part of the piston is an area about 1/2” above where the skirt ends and at 90 degrees to the wrist pin. This is the area to be measured when calculating piston / bore clearance. This will always be the first area of the piston that starts to show signs of being worn.
2.Evidence of the hone pattern only being visible on the bottom sides of the cylinder is normal.
Make sure the rings are in the correct way. I'm assuming you run a Wiseco piston. The rings will be marked on one side. The mark faces up. It doesn't matter where you put them ( top or bottom groove ) if everything is new but never switch the position after the engine has been run. Lay the rings on a flat surface and make sure they're still flat and not distorted. Check the ring end gap. It should be at least .011. Just push the ring into the top of the bore about an inch and check with a feeler gage. The ring has to be parallel to the top of the bore to get an accurate measurement. Check the clearance between the ring and the ring groove in the piston. Anything over .002 is bad. You can also measure the width of the ring but you'll need a set of dial calipers. You should find no variation in the width. If you do, note where the ring gets smaller in relationship to the cylinder. Pay particular attention to the thickness of the ring in relationship to the exhaust port. Check the piston / cylinder clearance. This cane be done with a feeler gage if you don't own a bore gage. With the piston and cylinder off the engine, slide the piston ( take the rings off) into the bottom of the cylinder. Slide a feeler gage between the cylinder and the bottom part on the skirt @ 90 degrees to the pin. DON'T FORCE IT!!!! Start with a .001 and work your way up .001 at a time. If a .002 wont go between the piston and the cylinder, you need more clearance. If a .005 goes in, time of a new bore. I typically run .0025 - .004 depending on what I'm doing with a certain engine. Don't even think about re-using the C clip. Check the ring locating pins in the back of piston, if you can move them or take them out, the piston is junk. Take a good look at the chamfers on the ports, they should be nice and round. Pay particular attention to the exhaust port. If you have a loop or magnifying glass, examine the face of the rings. Look for any burrs. This should help but if after all this you don't find anything, give me a call. I'll be in the shop all day. 860-230-5003
Ken
1.Pistons are not straight. The top ( where the rings go ) is smaller in diameter than the bottom skirt. The largest part of the piston is an area about 1/2” above where the skirt ends and at 90 degrees to the wrist pin. This is the area to be measured when calculating piston / bore clearance. This will always be the first area of the piston that starts to show signs of being worn.
2.Evidence of the hone pattern only being visible on the bottom sides of the cylinder is normal.
Make sure the rings are in the correct way. I'm assuming you run a Wiseco piston. The rings will be marked on one side. The mark faces up. It doesn't matter where you put them ( top or bottom groove ) if everything is new but never switch the position after the engine has been run. Lay the rings on a flat surface and make sure they're still flat and not distorted. Check the ring end gap. It should be at least .011. Just push the ring into the top of the bore about an inch and check with a feeler gage. The ring has to be parallel to the top of the bore to get an accurate measurement. Check the clearance between the ring and the ring groove in the piston. Anything over .002 is bad. You can also measure the width of the ring but you'll need a set of dial calipers. You should find no variation in the width. If you do, note where the ring gets smaller in relationship to the cylinder. Pay particular attention to the thickness of the ring in relationship to the exhaust port. Check the piston / cylinder clearance. This cane be done with a feeler gage if you don't own a bore gage. With the piston and cylinder off the engine, slide the piston ( take the rings off) into the bottom of the cylinder. Slide a feeler gage between the cylinder and the bottom part on the skirt @ 90 degrees to the pin. DON'T FORCE IT!!!! Start with a .001 and work your way up .001 at a time. If a .002 wont go between the piston and the cylinder, you need more clearance. If a .005 goes in, time of a new bore. I typically run .0025 - .004 depending on what I'm doing with a certain engine. Don't even think about re-using the C clip. Check the ring locating pins in the back of piston, if you can move them or take them out, the piston is junk. Take a good look at the chamfers on the ports, they should be nice and round. Pay particular attention to the exhaust port. If you have a loop or magnifying glass, examine the face of the rings. Look for any burrs. This should help but if after all this you don't find anything, give me a call. I'll be in the shop all day. 860-230-5003
Ken
^^^^^ there ya go.... ^^^^^^ The brains of this operation chimed in.... He lost me at point "1." haha just kidding
Thanks Ken thats why you are so valuable to this forum!
Thanks Ken thats why you are so valuable to this forum!
