DS80 engine split

[GooseMan]

Hey I need to split open my engine but am not sure if it requires any specialist tool or something, I got all the standard tools, would this be appropriate, I ask because I don't want to have my engine in pieces while searching for some tool. It has a death rattle, so I think it is the bearings on the con rod. Also if anyone has spit a ds80 92 engine before I would really appreciate it if you could give me some tips, Thanks in advance

 

[cozza123]

Label these basic tools

You'll need a fly wheel puller and clutch tool to under the nut holding the clutch on.

 

[my67xr]

nice, another DS80 owner, and from SA too.

have you taken the head off and checked how much play the piston has?
it may need to be honed and a new piston, rings and associated gaskets.
or worst case a rebore.
wont cost that much to do.
if you have any problems get in contact with me.

i fixed up a mates '82 RM80 a few months ago.
he bought it cheap, not running and got a spare bike with it, missing a fair few bits.
the good/complete bike wasnt selecting gears,
i pulled it down and checked things out, clutch basket was all notched/worn from old age
and the clutch plates had no friction material left on them.
it was also missing a couple of circlips on the gearbox shafts
while i had it apart i also noticed it had a bent selector lever
luckily he had a spare motor, i picked the best parts from both and got it all working again.
it goes pretty hard too, brings back memories riding them and the YZs back in the 80s, lol

i just replied in another DS80 thread too a few mins ago.
i might have to start a build thread on my '86 DS80

cheers, craig

 

[GooseMan]

thanks craig, saw your ds80 rebuild and it looks great, make me wanna restore mine like that.
haven't seen the piston for a couple of years now but it did get new rings at the time by a mechanic.
Tools; I have a flywheel puller that will fit but no clutch tools, were could I find one of these to fit? other tools include sockets and spanner imperial and metric, screwdrivers etc

 

[my67xr]

you wont need any of the imperial tools, lol

lucky the flywheel puller is the same as most pit bikes hey?
i bought one for my Yamaha IT, same one fits the pittys and the DS.
i didnt use a tool to undo the clutch bolt on my mate RM, an impact socket and a decent whack on the breaker bar loosened it, same to retighten.

so does your motor rattle have a ting,ting kind of sound or more of a knocking noise?

 

[GooseMan]

Its more of a knocking sound, im pretty sure it's bearing, if not then it's something in that area. The weird thing is that on the rare occasion it will randomly stop knocking and run sweet but that only lasts about a minute and then its bad again. It definitely knocks off a hp's.

Do you think a general socket set will get the clutch apart.

 

[my67xr]

yeah it should be ok.
im from marion area if you ever need to borrow something.

i think i know what the noise might be.
my original DS motor had a bit of play inthe big end, crank area.
i popped the seal out from behind the stator and found out what it was.
you can do that without pulling the motor apart.

at least one crank bearing had failed, the whole race that holds the balls is missing.

 

[GooseMan]

well i have found time to check out the bike, I have pulled it apart and have found that the same bearing as yours my67xr, has destroyed it self. Where did you get your bearing from? I figure I may as well replace all the bearing while I have it apart. Do you think a bearing shop might have some in stock to fit.

I have work exp at Victor Motorcylce's next week so they may be able to help may out if I can't source. I have seen them in the us but don't really want to wait that long if I can help it.

 

[my67xr]

you need to find decent quality 6304 bearings, 2x are needed, one for each side of the crank, an open bearing design (eg; no rubber seals)
20mm inside diameter, x 52mm outside diameter, x 15mm wide
most bearing places will have them in stock, cbc bearings etc
and you'll need new seals too,
take your old ones with you as samples, seals should have part numbers on them

tell them they're a crankshaft bearing for a motorbike.

 

[GooseMan]

all right thatnks but one of the two bearings has a groove in the outside of it and large circlip looking thing fit in it, do you think a bearing shop will stock that sort of thing? I go down to a shop tomorrow and see what they have anyway.
Also do you think it is worth replacing the top and bottom roller bearings of the con rod? The bottom one is quite expensive online.

 

[Cactus Jack]

It's always a good investment to replace the rod , pin and big end bearing ... If you've ever had a 2 stroke grenade a rod bearing then you'll know what I mean ...The big end roller cage shatters from being hammered by up and down play in the rod ...

To test the big end bearing , push the rod downwards on the crank and rap on the end of the rod with something soft (rawhide / rubber hammer or the wooden handle) and note the sound you hear (it should sound dull and solid) ... then pull the rod upwards and rap on the end again noting the sound you hear (it should still sound dull and solid) ... IF the sound changes at all (as in a click , knock , tap etc) then there's excessive big end play and you're sitting on a potential time bomb (ie severely scored bore , destroyed piston and rings , roller cage shrapnel impregnated in the head and worst case scenario ... smashed cases from a broken rod if the rollers go thru the case hardening and weld / seize in the softer part of the rod) ... I've even seen the fronts of cylinders smashed out (aka windowed ) ... And I've seen motors totally junked from a crank blow-up ...

I recently bought a 2007 CRF250R bottom end from the USA and the seller reckoned the crank was good ... Just like most people would think going off how the rod "feels" by hand ... But the sound changes in a "rap" test so it's getting a new or fully rebuilt crank ...

 

[GooseMan]

bit late now! its all back together and I don't really want to be pulling it apart, would I be able to hear if the bottom bearing is crap or if I need a new con rod while it is running?

 

[Jonathanmartinez749]

nice, another DS80 owner, and from SA too.

have you taken the head off and checked how much play the piston has?
it may need to be honed and a new piston, rings and associated gaskets.
or worst case a rebore.
wont cost that much to do.
if you have any problems get in contact with me.

i fixed up a mates '82 RM80 a few months ago.
he bought it cheap, not running and got a spare bike with it, missing a fair few bits.
the good/complete bike wasnt selecting gears,
i pulled it down and checked things out, clutch basket was all notched/worn from old age
and the clutch plates had no friction material left on them.
it was also missing a couple of circlips on the gearbox shafts
while i had it apart i also noticed it had a bent selector lever
luckily he had a spare motor, i picked the best parts from both and got it all working again.
it goes pretty hard too, brings back memories riding them and the YZs back in the 80s, lol

i just replied in another DS80 thread too a few mins ago.
i might have to start a build thread on my '86 DS80

cheers, craig