PISTON & REBORE advice
Moderatoren: Kristian, tester_änderung
PISTON & REBORE advice
Does anyone know the upper and lower limits of diameter for each of the 4 stock size pistons?
Is there a marking somewhere on the piston to show what size it is?
Is there a marking somewhere on the piston to show what size it is?
Re: PISTON & REBORE advice
According repair handbook "Bucheli" Chapter 2.1 the diameter of the standart piston should be:
88,97 - 88,99 mm (10 mm below top of piston).
The limit is: 88,88 mm.
The oversized piston have stamped on top: 0,25 or 0,50 or 0,75 or 1,00 and "IN" for intake side.
The serial piston has just the "IN".
If you need more data search for the repair manual from our italian friends: "WHB_Honda_XR_Kapitel07 Kolben Zylinder.pdf"
88,97 - 88,99 mm (10 mm below top of piston).
The limit is: 88,88 mm.
The oversized piston have stamped on top: 0,25 or 0,50 or 0,75 or 1,00 and "IN" for intake side.
The serial piston has just the "IN".
If you need more data search for the repair manual from our italian friends: "WHB_Honda_XR_Kapitel07 Kolben Zylinder.pdf"
Bub, bub, bub...
Re: PISTON & REBORE advice
thank you Kristian.
Do you have a link for the repair manual as nothing comes up for me on google?
Do you have a link for the repair manual as nothing comes up for me on google?
Re: PISTON & REBORE advice
10mm below top of piston? That is NEVER the right point to measure the diameter of a piston. Another mistake in Bucheli?
Cheers,
Hans
Cheers,
Hans
Re: PISTON & REBORE advice
I'm new to this, where would you measure it, the pin?
Re: PISTON & REBORE advice
Hello Baldock,
Here are the measurements for the piston and the piston pin. Most right, the Service Limit.
Also where to measure it.
The next sizes are +0.25 / +0.50 / +0.75
Best regards
Gunnar
Here are the measurements for the piston and the piston pin. Most right, the Service Limit.
Also where to measure it.
The next sizes are +0.25 / +0.50 / +0.75
Best regards
Gunnar
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XL500R / Bj 82
Moto 6.5 / Bj 96
Die besten Kapitäne stehen an Land!
WAFI: Wind assisted freaking idiot
Moto 6.5 / Bj 96
Die besten Kapitäne stehen an Land!
WAFI: Wind assisted freaking idiot
Re: PISTON & REBORE advice
the piston only has 'IN' so I assume is standard size.
Piston measures:
88.62mm (TOP), 89.01mm (MIDDLE), 88.99mm (BOTTOM)
cylinder bore measures:
89.29mm (TOP), 89.30mm (MIDDLE), 89.32mm (BOTTOM)
Piston measures:
88.62mm (TOP), 89.01mm (MIDDLE), 88.99mm (BOTTOM)
cylinder bore measures:
89.29mm (TOP), 89.30mm (MIDDLE), 89.32mm (BOTTOM)
Re: PISTON & REBORE advice
would the above measurements be ok to just hone the cylinder and put my NOS standard piston/rings in?
Re: PISTON & REBORE advice
So if I calculate right: the piston has ~0.31mm clearance in the bore, but should have a max. of about 0.10mm. (see the line next to last "piston to bore-clearance")
As you see: Honing wouldn's solve the Problem..
You will need a new piston two sizes over. But I would recommend to visit a qualified motor-repair-shop and ask there for measuring cylinder and piston.
Cheers,
Hans
Re: PISTON & REBORE advice
Fascinating!
To me it looks like your cylinder was honed for the first oversize and the original piston was installed. A mistake in the reassembly?
You should hear that much play, it's called piston tilt.
I agree with Hans, ask a good engine repair shop what to do.
Cheers
Gunnar
XL500R / Bj 82
Moto 6.5 / Bj 96
Die besten Kapitäne stehen an Land!
WAFI: Wind assisted freaking idiot
Moto 6.5 / Bj 96
Die besten Kapitäne stehen an Land!
WAFI: Wind assisted freaking idiot
Re: PISTON & REBORE advice
thanks
Re: PISTON & REBORE advice
I took the cylinder and old standard piston, a new +.25 piston and a new +.5 piston to the machine shop.
The +.25 just dropped straight through the bore with too much slop.
Engineer felt a slight groove in bore then said they'll rebore/hone for the .5 and see if the groove is gone.
If not, I can't rebore to .75 as I don't have a piston that size.
fingers crossed
The +.25 just dropped straight through the bore with too much slop.
Engineer felt a slight groove in bore then said they'll rebore/hone for the .5 and see if the groove is gone.
If not, I can't rebore to .75 as I don't have a piston that size.
fingers crossed
Re: PISTON & REBORE advice
"a slight groove in bore" That's new for us.
Where does it come from? Do you have a picture?
To take the next size (+0,50) is okay.
Good luck for rebore/hone
Cheers
Gunnar
Where does it come from? Do you have a picture?
To take the next size (+0,50) is okay.
Good luck for rebore/hone
Cheers
Gunnar
XL500R / Bj 82
Moto 6.5 / Bj 96
Die besten Kapitäne stehen an Land!
WAFI: Wind assisted freaking idiot
Moto 6.5 / Bj 96
Die besten Kapitäne stehen an Land!
WAFI: Wind assisted freaking idiot
Re: PISTON & REBORE advice
is there a place you guys get your pistons/rings from in case I need to get a +.75?