Hi

I have a 1984 Dt175 which i re-oil the forks with 254cc of 10w oil but when i went for a ride it was bottoming out .

Do i have the wright oil and CC?. or should i use a heavy oil

Thanks if you can help

Hi

I have a 1984 Dt175 which i re-oil the forks with 254cc of 10w oil but when i went for a ride it was bottoming out .

Do i have the wright oil and CC?. or should i use a heavy oil

Thanks if you can help

Hi Paul, where did you get the figure 254cc from, Its 146cc +-2 of 10w / 15w/ 20w...depending on weight of rider

Hi Paul, where did you get the figure 254cc from, Its 146cc +-2 of 10w / 15w/ 20w...depending on weight of rider

Sounds like they are locking out then?

Sounds like they are locking out then?

Hydraulic lock!! no wonder thy felt like bottoming.

Hi Paul, where did you get the figure 254cc from, Its 146cc +-2 of 10w / 15w/ 20w...depending on weight of rider

Thanks for the reply. a yamaha service center gave it to me and he told me if i put a heavy oil in like 15w it could blow the seals.

thanks

Thanks for the reply. a yamaha service center gave it to me and he told me if i put a heavy oil in like 15w it could blow the seals.

thanks

Then use another service centre cos thats bollox, If you put enough force into the forks to blow seals in good nick on good chrome you will prob knacker the fr wheel.

Hi Paul, where did you get the figure 254cc from, Its 146cc +-2 of 10w / 15w/ 20w...depending on weight of rider

Hi what is Hydraulic lock???

Hi what is Hydraulic lock???

The figure OG has quoted will be allowing for an 'air gap' which will allow room for the oil to move. As when the forks compress the chrome section moves inside the lower part of the leg. Like when you get in the bath. If you filled it to the very top then got in it would go every where.

Well the thing with the forks is they are a sealed system so the spare oil cannot escape like the water in your bath and so the forks will stop moving when the oil runs out of room. Hence the air gap. In theory if you fill the forks fully compressed you would be somewhere near but thats hardly accurate.

The figure OG has quoted will be allowing for an 'air gap' which will allow room for the oil to move. As when the forks compress the chrome section moves inside the lower part of the leg. Like when you get in the bath. If you filled it to the very top then got in it would go every where.

Well the thing with the forks is they are a sealed system so the spare oil cannot escape like the water in your bath and so the forks will stop moving when the oil runs out of room. Hence the air gap. In theory if you fill the forks fully compressed you would be somewhere near but thats hardly accurate.

thanks for the reply

do i need to compress the forks when i refill the forks and do you know how much of a air gap i should have in the top of the fork?

Get a helper, remove the drain screw at the bottom of each fork, do one side at a time, hold a container against the hole and SLOWLY compress the fork, do this until it is empty, then do the other side. BEWARE the oil can squirt out at a fair old whack so hold the container correctly and dont pump too hard.

Then measure the correct amount of the oil and put it back in the top having first replaced the drain plugs

The key is, to be sure they are empty before filling them, dont worry about air gaps.

Get a helper, remove the drain screw at the bottom of each fork, do one side at a time, hold a container against the hole and SLOWLY compress the fork, do this until it is empty, then do the other side. BEWARE the oil can squirt out at a fair old whack so hold the container correctly and dont pump too hard.

Then measure the correct amount of the oil and put it back in the top having first replaced the drain plugs

The key is, to be sure they are empty before filling them, dont worry about air gaps.

what weight oil should i use i'm 85kg?? and i'll try 146cc and i will be riding on the dirt if that make any diffidence

thanks

what weight oil should i use i'm 85kg?? and i'll try 146cc and i will be riding on the dirt if that make any diffidence

thanks

you might as well re use the oil 10w that you drained, after all it is new oil, unless it looks cruddy, then if thats too soft try again with 15w and so on.