atc/trx250r sprocket washer and headgasket question

[Sparkplugkid]

hey guys I am slightly confused about the washer that holds my sprocket on. its a 88 trx250r but im pretty sure the 86 atc250r is the same. On the honda parts fiche it shows a normal washer 8X40mm...but I saw a 350x sprocket has what they call a plate fixing which has 2 small bolts through it threaded into the sprocket itself (PLATE, FIXING 23811-HA5-670) where the trx/atc has this listed WASHER (8X40) 90501-HB9-003 (replaces 90501-KA3-741). My sprocket has those 2 small holes in it, but right now what I have is a washer that I drilled the hole big enough to fit on the shaft. The end of the shaft sits flush with the washer when mounted. I have another washer to hold the big washer in and finally the bolt. Will my setup work? Another question I have is the head gasket. The manual says the "mark" goes up if I remember correctly (dont have it off hand). I couldnt find the "mark" so i guessed (bad idea I know). I just realized today that the cylinder and head have a slight square machined into at the back where they come together. My gasket isnt lined up in those 2 square markings. looks maybe a 1/2" off. Is this another way to tell if its on incorectly? can anybody help? If I flip it upside down will it line up then? any tricks to getting the head off when the engine is mounted? thanks I am just 16 and still learning. oh and the machine hasnt ran yet, I know if the head gasket is installed incorectly cooling issues can occur thanks

[falloutboy]

got any pictures?

[Sparkplugkid]

yes i can go take some

[Dirtcrasher]

Lots of sprockets are drilled/tapped for other applications. I don't know the TRX but it's basically a 250R and should have a bowed washer for the center bolt. I usually see the 2 small bolts on four strokes; Simply look at your shaft. If it is coarse splined, it will use 2 bolts and a plate, if it is fine thread, it will use a bowed washer and a center bolt to hold it in place.

I try to get OEM gaskets to avoid confusion but usually looking at them helps you figure it out. I have only had success with Vesrah and OEM, the others have had issues........

[Sparkplugkid]

thanks for the help is there supposed to me some movement