Jump to content

21cc to 20cc


yamaha04

Recommended Posts

I set most all of our motors up at .003 clearance , if you had another builder tell you it wasnt bad enough to tear down im not sure how we know its bad enough to accuse me of boring it to "to big of bore". All motors if you take the head off and push on the piston it will rock back and forth as the top of the piston is much smaller in diameter than the skirt. Several times in this topic you stated it started making noise after 3 hours of riding , if it was piston slap normally they are loud right away and especially cold as when the motor heats up and piston expands they get quieter. Is it possible that the noise is your crank? Maybe a piston skirt collasped for some dumb reason who knows , things happen and i didnt assemble the motor. Anyway, what can i do to help?? If you want to send them back i will bore them at no charge and fire them right back out quickly IF NEEDED!!!!

Link to comment
Share on other sites

well i hope its not the crank you true and welded it and told me the bearing where good. im kinda stumped the builder said it was piston slap but it wasnt bad enough to tear it down he said ride it but it will get worse and it did so i tore it down to find the piston looking perfect and you could still see hone marks in the cylinders. can anyone give me there advice on what it could be? im getting it bored again already so thats not needed. thanks anyway

Edited by yamaha04
Link to comment
Share on other sites

accualy if you read up it said i called him from the dunes asking him question on my motor and he said oh its probably your flywheel lose knocking back and forth on the crank. im not bad mouthing the guy. but he sure isnt makeing a very good impression in my books after he comes on here and tells me it could be my crank. lol fun how he was the one that trued and welded didnt put new bearings on it when i told him to if they where shit. i dont really see him replying to that. listen dude im not bad mouthing its just one thing turned into another and the story came out. im just looking for answers on why my motor os makeing this nosie and hoppfully i will find out when i hear back from the guy thats boring it.

Link to comment
Share on other sites

accualy if you read up it said i called him from the dunes asking him question on my motor and he said oh its probably your flywheel lose knocking back and forth on the crank. im not bad mouthing the guy. but he sure isnt makeing a very good impression in my books after he comes on here and tells me it could be my crank. lol fun how he was the one that trued and welded didnt put new bearings on it when i told him to if they where shit. i dont really see him replying to that. listen dude im not bad mouthing its just one thing turned into another and the story came out. im just looking for answers on why my motor os makeing this nosie and hoppfully i will find out when i hear back from the guy thats boring it.
Link to comment
Share on other sites

accualy if you read up it said i called him from the dunes asking him question on my motor and he said oh its probably your flywheel lose knocking back and forth on the crank. im not bad mouthing the guy. but he sure isnt makeing a very good impression in my books after he comes on here and tells me it could be my crank. lol fun how he was the one that trued and welded didnt put new bearings on it when i told him to if they where shit. i dont really see him replying to that. listen dude im not bad mouthing its just one thing turned into another and the story came out. im just looking for answers on why my motor os makeing this nosie and hoppfully i will find out when i hear back from the guy thats boring it.

 

Well then let me reply : Forgive me if i dont remember every single thing i do and ship out for people. You were'nt the only one i did cylinders or crank work for in the year 2007. lol I asked what I could do to help and offered to do the work for free even though; I didnt assemble your motor and you said it started making noise AFTER 3 hours of riding. I asked if it was possibly noise from your crank as bearings can go bad. If i checked them, then they were fine when it left here, trust me i would of been more than happy to sell you new parts IF it needed them right?!!!$ From the looks of your pistons if it was too big of a bore you would've had brown/black marks (blow by) coming down past the rings around the top sides of the piston (which you dont). Anyone that knows me, knows I go out of my way to make things right. You have someone else doing it now so there is not much more i can do to appease you from the sounds of it.

Link to comment
Share on other sites

thanks anyway jeff. yeah ot started makeing the nosie after the first 3 hours i had my motor back together. then everytime aftet that when i started it, the sound whats there right away. i was always nervious about the sound so i checked my compression all the time, the compression stayed up all season. but the noise got louder as the season went one. but the performace of the bike was aways the same aswell it never ran like shit. accualy i ran good beating pretty much everything i raced other then the ported bikes. if its my crank bearings can i check them by just turning them and listening and felling if the spin freely. or can i use some feeler guages some how?. when i get my cyilnders back what should the ring gap be?

Link to comment
Share on other sites

Just wanted to add my .02 here

It's to bad that you didn't pursue working with Jeff a little longer. I understand how one gets gun shy in a situation like this but Jeff's one of the most credible and honest guy's I've ever known. I think anyone who has really got to know him would agree. He'd do WHATEVER was needed to find your problem and although a slim chance it's possible a measurement or whatever could have been off (we're all human) but he'd definetly make it right even if it cost him out of his own pocket. Thats just the kind of guy he is...Each of us is out to make a living at whatever business we're in but Jeff is the kind of guy where honesty and his good name trump the dollar.

Link to comment
Share on other sites

i run a stock head shaved 135psi run on pump gas , the power is not from compression but from air and fuel , porting makes power , i wouldnt waste time switching domes to high compression and then have to pay to run race gas .

 

It seems this thread has gone another direction, but I thought I would point this out. Compression certainly DOES increase power. True, bigger gains can be had through improved and additional air/fuel flow. But to say that compression does not add power is completely incorrect.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...