motonut58
XS650 Member
hi all, can someone tell me the correct size and grit for a rering flex hone for my stock xs cylinders. Thanks
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hone grit for rering?
- Thread starter motonut58
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- engine fabricating
motonut58
XS650 Member
I know its a real tech. Question, I assume no one has honed their own cylinders
cros36
thread killer
this was a good read that was posted on a different site a little bit ago.
http://www.snowvalley.20m.com/bikes/dnthone.htm
it makes sense to me. in the end your only going to increase the ring gap causing less compression. but it has been done for years and years so this pry wont change alot of peoples minds. maybe i just see it as an excuse not to hone my cylinders. i dont know. im sticking with the article.
http://www.snowvalley.20m.com/bikes/dnthone.htm
it makes sense to me. in the end your only going to increase the ring gap causing less compression. but it has been done for years and years so this pry wont change alot of peoples minds. maybe i just see it as an excuse not to hone my cylinders. i dont know. im sticking with the article.
Yes, it is kind of techie, beyond what most here do on their own. I use a 3" (76mm) Flex-Hone in the 180 grit (part #BC30018) which I got here (their part #BC3") ......
http://www.ruffstuff.com/pages/flex.html
The XS cylinders are a hair over 75mm but Flex-Hone doesn't make that size. They instruct you to get the next larger size if your size isn't made. The hones have a very narrow range, something like 1/4" to 1/2". So far for my various bikes, I've needed to buy 4 different sized ones.
http://www.ruffstuff.com/pages/flex.html
The XS cylinders are a hair over 75mm but Flex-Hone doesn't make that size. They instruct you to get the next larger size if your size isn't made. The hones have a very narrow range, something like 1/4" to 1/2". So far for my various bikes, I've needed to buy 4 different sized ones.
The hones come in different grits so you can use the coarser grits when you have heavy rust or pitting. Once you get the rough stuff done you can use a finer grit to finisn hone. Once you get the honing done you need to check ring end gaps. Check gaps at several places in the wear area of the cylinder. The cylinders wear in a taper. If you set the gaps in the largest area of the taper they may get to tight in the smallest spot.
Leo
Leo
motonut58
XS650 Member
so thanks for all the info, the book says the cylinder bore should not exceed 2.954 in., mine measures 2.955 in. My cylinders are pretty clean (15000 miles) I had a bent valve and a small oil leak at the upper gasket, so I thought sense I'm in this far I might as well hone and rering so am I ,wasteing time and money going this route? Or should I break out the plastic and go with a bore and pistons?
The Yamaha service manual for my 78SE said cylinder wear limit was 2.9567", and allowable taper is 0.002"
Also check the cylinder to piston clearance. With piston at bottom of cylinder,you should not be able to put a 0.004" feeler gauge between piston and cylinder. 0.002" is good and 0.005" is bad.
www.biker.net has the Yamaha service manuals, with the specs. If your engine falls within the specs then no need to spend money on pistons/rebore.
Also check the cylinder to piston clearance. With piston at bottom of cylinder,you should not be able to put a 0.004" feeler gauge between piston and cylinder. 0.002" is good and 0.005" is bad.
www.biker.net has the Yamaha service manuals, with the specs. If your engine falls within the specs then no need to spend money on pistons/rebore.
Tim of DO THE TON
XS650 Junkie
While we're on the topic... I'm going to be taking my 2000 mile old (fresh pistons/rings 0.5mm bore 2 years ago) apart for soda blasting and a taller 5th gear. Should I replace the rings and hone the cylinders or is it kosher to just reassemble?
Planning on masking off the cylinders for soda blasting, which is likely not needed but whatever. Logic tells me just stick the pistons back where they came from and put it back together. 150+ PSI on compression tests - engine running great, but leaky tappet covers (two stripped studs in head) are prompting me to take it apart, replace the head/rocker cover (which are supposed to be kept together like the cases) and put it back together.
This is the engine I pulled out of my bike to replace with the 750 rephased motor I just finished. It's going into a Voodoo frame. Just cleaning it up - no performance mods, aside from the 5th gear (although rephasing it is tempting).
Planning on masking off the cylinders for soda blasting, which is likely not needed but whatever. Logic tells me just stick the pistons back where they came from and put it back together. 150+ PSI on compression tests - engine running great, but leaky tappet covers (two stripped studs in head) are prompting me to take it apart, replace the head/rocker cover (which are supposed to be kept together like the cases) and put it back together.
This is the engine I pulled out of my bike to replace with the 750 rephased motor I just finished. It's going into a Voodoo frame. Just cleaning it up - no performance mods, aside from the 5th gear (although rephasing it is tempting).
If soda blasting, why tear the engine down? Just plug all the holes and blast.
Leo
Leo
It's interesting but when something flies so hard in the face of convention my first thought is it's a quack speaking.
Tim of DO THE TON
XS650 Junkie
not meaning to hijack - but I'm putting the taller 5th gear in, and the original issue that drove me to ultimately build the new engine in the first place is two stripped studs on the two right tappet covers. Tried inserts, JB weld etc. etc. to fix it but never sorted it out.
So that problem remains and I'm pulling the head to fix it (likely replacing the head). And frankly after doing the last engine (my first full engine build) it's 1000x easier than I though it was and I'm looking forward to tearing it down completely, replacing all the seals properly, fresh Yamabond etc. and having a leak-free engine. My current engine is leak-free after 200 miles. Just a tiny bit of seeping on the starter gear cover gasket and even less on the clutch engine cover. No drops on the floor, just a bit moist on the seams.
cros36
thread killer
like the world being round, or washing your hands before surgery, or the belief in god....
like the world being round, or washing your hands before surgery, or the belief in god....
Exactly. He is saying the World is square, don't wash your hands, there is no God, and don't hone your cylinders
http://www.snowvalley.20m.com/bikes/dnthone.htm
So, has anyone out there actually tried this on an XS650? (Installing new rings without honing the cylinders.)
So, has anyone out there actually tried this on an XS650? (Installing new rings without honing the cylinders.)
Back in the `70s, had a new (supposedly) mechanic do a couple top-end-OH, didn't know to hone.
His jobs came back smoking.
I could shoot so many holes in that 'don't hone' manuscript I'd run outta ammo...
His jobs came back smoking.
I could shoot so many holes in that 'don't hone' manuscript I'd run outta ammo...
About 4 years ago my engine needed the top end, to come apart, due to a head gasket that was passing oil badly, and engine was using a ton of oil. Pistons and heads were coated with large amounts of carbon. Once it was apart, I took some careful measurements, and found that the cylinders/pistons were still in spec. Factory cross hatching was still visable on cylinders. Engine had about 20,000 kms on it.
I used 240 grit emery paper by hand, to scratch up the cylinder walls. That was followed by washing twice with hot water and soap. So you could call this a light de-glaze, and I suspect that a Flex-hone (ball-hone) could also have been used for the same purpose. I think the name Flex-hone would be more correctly called a Flex-deglazer.
To my understanding, a honing (using stones) removes material from the cylinder walls (as required after a machined re-bore), while a de-glazing, such as using a Flex-hone, does not remove material.
I installed new stock size rings, and the engine has run perfectly, using no oil, since then.
So, yes I did install new rings and I did not hone the cylinders.
After a re-bore, using a hone is the correct way to go. However, if not reboring, cylinders/pistons are in spec. , then just use a Flex-hone (ball-hone), or you may be able to just de-glaze by hand as I did.
"Factory cross hatching was still visible on cylinders" <--- Bullet hole #1
Thank you RG...
Thank you RG...
