xs650 Sumotrack
- Thread starter Rat_ranger
- Start date
Rat_ranger
Coast to Coast
The dyno with fans running was the whining noise. AFR could have been a little richer, and accel enrichment needs work. It started getting a little blow by as soon as it got on the dyno, and didn't get any tuning because it was getting worse. I told him to just do a power run as any damage was already done. So it might be a little flat from the oil getting into the right cylinder.
I'll use this as my excuse to go to a 700cc set up. I already put a bore scope in to make sure out didn't hole a piston. But it's something with the rings on the right cylinder. Everything else checks out.
Kind of annoying since it was fine on sunday when I put in the 8 plate clutch, synced throttle bodies, and did a valve check.
I'll use this as my excuse to go to a 700cc set up. I already put a bore scope in to make sure out didn't hole a piston. But it's something with the rings on the right cylinder. Everything else checks out.
Kind of annoying since it was fine on sunday when I put in the 8 plate clutch, synced throttle bodies, and did a valve check.
Aussie Steve
As useful as an ashtray on a motorcycle!
Bummer to hear that.Rat_ranger said:
Sent from my SM-A530F using Tapatalk
That all sounds plausible.
It's unfortunate it happened, but great opportunity to build it bigger and stronger. Life is a journey and so are projects. First time they are "finished", all they are really doing is taking a rest before the next round of changes.
Onward and upward.
It's unfortunate it happened, but great opportunity to build it bigger and stronger. Life is a journey and so are projects. First time they are "finished", all they are really doing is taking a rest before the next round of changes.
Onward and upward.
Rat_ranger said:
Rat_ranger
Coast to Coast
Yeah. The good thing is the EFI is proven and working, just needs fine tuning. I did want to go big bore, it just wasn't in the budget back then. Now I have high ratio primary gears coming and can afford to go big bore with some overtime.
Rat_ranger
Coast to Coast
The video was the end of getting it to temp. It was only going up to 6k. On the power run it was taken up to the limiter at 7800. Power had rolled over right before 7500 so unless I do something with the head or get a cam hotter than the XS1 I'll leave it set at 7800.
crazypj
Split personality, I fake being smart
Did you fit XV750 intake valves? Relatively cheap and easy oversize from the stock 650 item. I've done a few, even opened valve seats and re-cut to get correct installed height. Exhausts don't need doing although many people fit them but working out max rpm gas flow, stock size are fine
Rat_ranger
Coast to Coast
Not head gasket or a ring failure. A wrist pin circlip failed, which caused the oil ring to get jammed, which gouged the cylinder. Such a simple part to kill an engine. So the fix will be a 700 kit. That'll take the bore big enough to remove the damage.
Attachments
hooligan998
Been Around the Block
Are spiral locks an option for you?
Rat_ranger
Coast to Coast
I could probably find some the right size. But I think it might have partly been the design on the circlips that came with the pistons. Instead of just being C shaped, they had a tail bent off one end that stuck into the middle. It could be as simple as I didn't seat it right, to the wrist pin knocking it out of place on install, or bad design. But the JE 700 pistons fron Hoos have normal c shaped circlips, and that is what will be going in.
crazypj
Split personality, I fake being smart
When fitting circlips, it's a good idea to have the 'heavy ' end at the top even with ordinary 'C' type. When you have a removal 'tail' there isn't a slot in piston to remove circlip, makes life a bit difficult so it's more important. Looking at the piston design, those were the wrong circlips for the piston.The inertia at TDC is much higher than at BDC. It's not in any Japanese service manual though as it 'shouldn't ' matter where they are. I always fit them heavy side up as I may exceed design rpm limits a little (or sometimes a lot) 
Pretty sure you would need circlip groves machined with a square bottom, probably more trouble than it's worth? Standard circlips will work fine to ~9,000rpm as long as they are fitted properly
Pretty sure you would need circlip groves machined with a square bottom, probably more trouble than it's worth? Standard circlips will work fine to ~9,000rpm as long as they are fitted properly
Rat_ranger
Coast to Coast
It's been a while, but there is an update. Doing a dry fit with the 700cc kit from Hoos racing. Gotta get some clay to check the piston to valve/head clearance. I was running without a base gasket and want to keep doing that if I can.
That's a pretty kit. Is the gasket from Lani, or part of the package and what thickness going without the base gasket?
Rat_ranger
Coast to Coast
It's the .042 thickness from coppergaskets63 on ebay. Clay was too hard to measure, I'm on the edge of being safe so I want to get a better measurement. So I have to dig my solder out tomorrow.
John Murray
Been Around the Block
I just read this whole thread - wow! Not only a very tastefully done bike but very impressive engineering and workmanship too. It's a credit to you and I look forward to what's yet to come with this bike.
Yeah, that's Lani at Copper Gaskets Unlimited. I would call him direct, if you keep using them, instead of buying them off Ebay. He'll give you a better price and a much more custom experience. He's awesome to work with.
Rat_ranger
Coast to Coast
Thanks! It hasn't been a fast build, and it has had plenty of stumbles and redos along the way. Part of this build was to prove to myself that the hack jobs I did in the past had taught me something and that I could do a good build with no hacking.
Good to know Irk. Despite everything I know and have learned there is always something new. Just gotta keep learning as I go and not get stuck in the mindset of "well I know this and it is right and nothing can change it."
Rat_ranger
Coast to Coast
Well I need to run a base gasket. Used solder to check the squish and came up with .02 to .025". Checked in 4 places twice. I've read you need about .040 to be safe.
