engine piston check
-
@erion1 You can find out the year of the bike using Yamaha France Parts Lookup as long as the frame has a VIN Number. They seem to have information on any Yamaha product sold in Europe, I've looked up UK bikes on there before:
https://www.yamaha-motor.eu/fr/fr/service-support/parts-catalogue/
@HOTSHOT-III i don have a vin it only has a fin someone told me it would be easy with a vin
-
Fux! I don’t know what to recommend. I forget sometimes how spoilt we are ‘in the west’. I’d go with the meteor piston if I was you. I wouldn’t go back to the same place that did your last rebore though, if I could find somewhere else. Get them to measure the bore, then supply the piston that fits the rebore that they do. There should be no noticeable movement in the barrel…
If you just want to get mobile again desperately, get a decent NEW head and base gasket. Lap the top of the barrel and head with wet and dry sandpaper on a sheet of plate glass…
I’ve done worse, just don’t cane the beast…Wish I could help you more…
@SpookDog it was good when i got it at firs as long as i remember, as for the rebore i got a oversize piston first then sent them together for him to make them fit and the oversize was enough to remove all the scratches, i think that it is movin a slight bit bc of the worn out rings and that it made contact with the cylinder only on those 2 sides and the rings weared ore on those 2 sides and not it taps, hope you understand what i mean
-
Bud! I’m guessing that the ‘scratch marks’ are spaced around the piston in 4 places?
This is because you reused a head gasket (worst 15 £-€ you never spent!) It’s called a 4 point heat seizure. If you look up inside of the piston, the inside of the crown will be black and scorched from the heat seizure. Whether you saw it on the temp gauge or not; it overheated…Other thing is the piston shouldn’t ‘click’ back and forwards if it’s the right size. Neither should you have that amount of blow by past the rings! I think that the person who did your rebore may of done you wrong…
I’ve used old bits to keep me on the road, but never as an end plan! Even then I rode it like a grandad, never above 5-6K max, never like a ‘yoof’…
What country are you in? Somebody might be able to recommend a good motorcycle engineer to help you move forwards…
You’re going to have to put in a proper fitting piston. Why quibble about a rebore?…
If you want to ride and enjoy your bike to the max. Just fix it please!… -
hey @SpookDog i was wondering if what happened could cause my crank bearing go bad as someone told me that, is there any way i can check that, i was thinkit that the water that got in caused corrosion on the bearing or something, i just don't want my engine to go boom haha
-
hey @SpookDog i was wondering if what happened could cause my crank bearing go bad as someone told me that, is there any way i can check that, i was thinkit that the water that got in caused corrosion on the bearing or something, i just don't want my engine to go boom haha
What are the first 5 letters and numbers stamped into your frame (headstock) and engine block? (above clutch arm) …
The crank would rumble when you spin it, and feel ‘notchy’ if it was corroded or damaged.
Also with ‘normal’ wear the stator could be moved, it’d click slightly when gently shimmied with a flathead screwdriver. Or even by hand depending on how bad it is…
I’d be more worried about you crank if it’s as bad as you say!… -
What are the first 5 letters and numbers stamped into your frame (headstock) and engine block? (above clutch arm) …
The crank would rumble when you spin it, and feel ‘notchy’ if it was corroded or damaged.
Also with ‘normal’ wear the stator could be moved, it’d click slightly when gently shimmied with a flathead screwdriver. Or even by hand depending on how bad it is…
I’d be more worried about you crank if it’s as bad as you say!…@SpookDog i checked for play when i had it apart it was perfect no up down play slight side to side which is normal and as the bike drank my water before i was thinking it could have litle bit of water in the crank so yesterday i put some 2t oil on the tank for more lubrication on the crank and let it run for a bit so it gets lubed up and maybe prevent corrosion if it didn't happen already
-
What are the first 5 letters and numbers stamped into your frame (headstock) and engine block? (above clutch arm) …
The crank would rumble when you spin it, and feel ‘notchy’ if it was corroded or damaged.
Also with ‘normal’ wear the stator could be moved, it’d click slightly when gently shimmied with a flathead screwdriver. Or even by hand depending on how bad it is…
I’d be more worried about you crank if it’s as bad as you say!… -
@SpookDog so you're saying i can rotate the stator if the crank is good, do you mean rotate with hand or with what, and can you explain a bit more what you mean by it would click when shimed with a screwdriver
You still have the barrel off yeah?
You should be able to rotate the stator easily by hand. It shouldn’t make any rumble noises or feel clicky/notchy when you turn it…If you gently lever the stator up and down it shouldn’t have any free movement. It might flex a bit if levered too much…
-
You still have the barrel off yeah?
You should be able to rotate the stator easily by hand. It shouldn’t make any rumble noises or feel clicky/notchy when you turn it…If you gently lever the stator up and down it shouldn’t have any free movement. It might flex a bit if levered too much…
@SpookDog no i put everything together as i needed space in my garage and had no place to put the parts and im not runing the bike either so its gona be like that for a month as i don't got the money for the new stuf rn but i'll take it apart again to check that then, but that what you told me is to check the crank bearings right? not the rod bearing it could be good if i can check both of them if they are in good condition without spliting the cases
Thanks for the info! -
You still have the barrel off yeah?
You should be able to rotate the stator easily by hand. It shouldn’t make any rumble noises or feel clicky/notchy when you turn it…If you gently lever the stator up and down it shouldn’t have any free movement. It might flex a bit if levered too much…
@SpookDog i did what you said but i didn't take the cylinder off i only took the sparkplug and took the stator side cover off,
it could be easily turned by hand and it has no movement up or down neither side to side no clicking no nothing just a little friction noisse wich i think is coming from the piston as its not in a good condition -
@SpookDog i did what you said but i didn't take the cylinder off i only took the sparkplug and took the stator side cover off,
it could be easily turned by hand and it has no movement up or down neither side to side no clicking no nothing just a little friction noisse wich i think is coming from the piston as its not in a good conditionBit of piston ‘scoosh’ is to expected in that condition
The crank turned real smoothly as well? No little stops or notchyness?
Bud! What are the first 3 numerics after the * on your engine and frame? If you let us know we can find out what year and model you have. It’s especially important when it comes to electrics…
-
-
Bit of piston ‘scoosh’ is to expected in that condition
The crank turned real smoothly as well? No little stops or notchyness?
Bud! What are the first 3 numerics after the * on your engine and frame? If you let us know we can find out what year and model you have. It’s especially important when it comes to electrics…
-
-
@MadGyver on the front brake hose it is repeated many times it writes DOT NCRN 12/91 1/8 HL im guessing that 12/91 refers to december 1991 maybe ?
-
That would tie in right. You have the 3 wire servo fitted to your bike don’t you?…
So it’s pre- 96 I think… -
That would tie in right. You have the 3 wire servo fitted to your bike don’t you?…
So it’s pre- 96 I think… -
@SpookDog i got a top end athena gasket kit but since i have to rebore to 57mm bore will it be a problem ?
-
No, I have a 58 I use (about 140cc)
You do have to check it doesn’t touch the power valve when it gets to a certain size…
-
@SpookDog yeah i know about power valve, i was just thinking would the top end gasket be smaller than the barrel but it should be fine
