1980 yz125 cylinder wanted

Hugh_Meah
Hi just wanted to see if anyone had a cylinder and would ship to England thanks
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TTperra
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TTperra 6/12/2016 6:14am
6/12/2016 6:14am
I think i have a -80 cylinder and head, have to look (and remember also..)
If my memory is right it needs new plating
project racer 6/12/2016 7:00am
6/12/2016 7:00am
If memory serves correct, the US spec models of 125G were iron bore, the euro models were plated.

Lots of seizure problems on the US models. Not so much on the plated cylinders.

Supposedly the seizures were caused by a casting on the carb bowl making contact with the cases, frothing the fuel, creating a lean condition.
nicko-31
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nicko-31 6/12/2016 3:08pm
6/12/2016 3:08pm
project racer wrote:
If memory serves correct, the US spec models of 125G were iron bore, the euro models were plated. Lots of seizure problems on the US models...
If memory serves correct, the US spec models of 125G were iron bore, the euro models were plated.

Lots of seizure problems on the US models. Not so much on the plated cylinders.

Supposedly the seizures were caused by a casting on the carb bowl making contact with the cases, frothing the fuel, creating a lean condition.
Wow !! Never heard that before. My favorite of all time Vintage bike though. Cool
Andy86
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Andy86 6/12/2016 3:46pm
6/12/2016 3:46pm
I would ask this guy i don't think he has one in stock but he can probably locate one its actually neil hudson's brother the YZM 500 rider from farleigh castle garry very nice guy and very reasonable prices

http://www.ebay.co.uk/sch/m.html?_nkw=&_armrs=1&_from=&_ssn=jackrussel_…

Or try keith at motolink yamaha spares

He has a nos 1981 cylinder listed but im not sure if it fits the 1980 model

http://motolinkyamaha.weebly.com/yz125h-1981-new-parts.html

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Dick Trickle 6/12/2016 5:29pm
6/12/2016 5:29pm
G was air coooled and the 81 H was the first of the water cooled. I had the white Euro model in Oz. All the G's were seizing. We had all sorts of problems. Cylinder head studs stretching and stripping, seizing, bending forks, blowing shocks, blowing holes in pipes.. Me and my brother went to a salt lake and he passed me on his 80 G when we were both going flat out. But, i loved that bike when it was running... very light and handled well. All the problems have been identified and sorted these days so would make a good vmxer.



fookyoo
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fookyoo 6/16/2016 9:39am
6/16/2016 9:39am
The best bike in 1980, Per Bob Fox
never ever remember seeing a broken one on side of track

fookyoo
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fookyoo 6/16/2016 9:42am
6/16/2016 9:42am
A friend found that letter on the tommy b's facebook page
project racer 6/16/2016 1:45pm
6/16/2016 1:45pm
project racer wrote:
If memory serves correct, the US spec models of 125G were iron bore, the euro models were plated. Lots of seizure problems on the US models...
If memory serves correct, the US spec models of 125G were iron bore, the euro models were plated.

Lots of seizure problems on the US models. Not so much on the plated cylinders.

Supposedly the seizures were caused by a casting on the carb bowl making contact with the cases, frothing the fuel, creating a lean condition.
nicko-31 wrote:
Wow !! Never heard that before. My favorite of all time Vintage bike though. Cool
MXA noted that in their test of the 125G also. They claim their test bike never seized, but nearly every other owner of a 125G they encountered at the track asked them, "has your bike seized / blown up yet" ?

There were a bunch of Wrench Report bulletins sent to the dealers regarding how to make them live a bit longer.

A friend had one, power was so late coming on, but good when it finally got to the upper RPM limits. It would fall on it's head between gear changes in the Florida sand if you shifted it before the cylinder was glowing cherry red.

TTperra
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TTperra 6/19/2016 1:04am
6/19/2016 1:04am
This is what i got, Think its -80, but im sure some one here knows.
Number on head is 3R300
and cylinder is 3N800
Cylinder needs plating or sleeve.





project racer 6/19/2016 8:55am
6/19/2016 8:55am
3N8 is the chrome bore (plated) non US model cylinder for the 125G
3R3 is the iron bore US spec .

Both bikes used the 3R3 head.

Piston and ring used different part numbers depending on US or Euro spec.

Cylinders for the 125G are scarce. One year only for the air cooled G.

That one looks like a great candidate for a re-plate.
BB67
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BB67 6/22/2016 2:21pm
6/22/2016 2:21pm
All the seizing problems were from head studs pulling. Install Suzuki TM 100 head studs problem solved.If you are going to ride/race it at all, do this now.

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