Jump to content

Pulled the motor, glad I did!


Recommended Posts

I have a the biggest trip of the year on March 30th. There will be around 10 other big sport bikes riding with me. Last year I discovered that one of my cylinders had a chuck of metal missing between the intake and boost ports. It still ran great, however I knew that I needed to replace my cylinders.

I was going to send them to Cam at redline. He didn't have any good used cylinders in stock so I had to find a pair. I bought a pair advertising a 64.50mm bore size. I got them and powder coated them red. Machinist states that they will need a 66.00 piston. Now I'm stuck with them because I can't return them because they are not in the condition that they were when I bought them. The seller gave me a round around as well. I decide to port them myself like the last pair but leave more room between the boost and intakes. Ordered 66mm wiseco pro lites and some V4's. All my parts, gaskets and misc showed up. Tonight I thought perhaps I should pull the motor and go through everything to make sure all is well. First discovery I found was the lower case was cracked by the rear sprocket. I poped a chain last year and it hit is so hard it put a 1 1/2" crack in the case in a non oil cavity. It also bent one of the chain guard bolts. So I need to get it welded so the crack doesn't spread to an oil cavity. Drained the oil and it had excessive amounts of fine aluminum flakes. Pulled the case half's apart and I can't see any damage anywhere. Only thing I can think is the the billet aluminum water pump gear if the source. The gear looks fine though, so again more weird.

I measured up the new cylinders versus the old ones. My intakes are 6mm longer then the last pair. And exhaust is 4mm wider then last pair. I wonder how much this will effect my jetting/performance? I also roughed up the trench and did some case porting. Brought the transfer opening on the outside to 4mm wide on both the jugs and case.

 

Link to comment
Share on other sites

Well, it should increase the A/F a bit, so might want to start a size or two richer for plug chop/read. Also make sure that the ex is radiused well for the extra width, and that there is good champher to aid the rings.

Derps like this is why we can't have nice things.

Link to comment
Share on other sites

Well, it should increase the A/F a bit, so might want to start a size or two richer for plug chop/read. Also make sure that the ex is radiused well for the extra width, and that there is good champher to aid the rings.

 

Exhaust port is radius-ed well. My machinist champhered the ports and did a nice job when he bored the cylinders.

Link to comment
Share on other sites

It seems I can't get it to seal up with just the gaskets in this area. I have to apply Yamahabond to both sides of the gaskets and then it will pass the leak down.

 

20140518_171131_resized_zps052f90aa.jpg

Edited by turbowrenchhead
Link to comment
Share on other sites

"My intakes are 6mm longer then the last pair. And exhaust is 4mm wider then last pair. I wonder how much this will effect my jetting/performance?"

 

These would be ported to some extent over stock.  If the bottom of the exhaust port matches up right at the top of the piston at BDC and the intake isnt raised close to the top of the intake tunnel they should work.  They may run very well for you.   

Edited by RadarRacing
Link to comment
Share on other sites

I misspoke even tho I read it correctly. If its a stock stroke the intake can be raised much higher on stock cyls. 4 mils shouldnt be near the top, thats why I mentioned it. I for some reason thought it was a 4 mil when I typed.

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...