need help on 85/89 250r engine

[dizasterzrfun69]

OK i'm starting to feel like ytmboy asking all these questions but try to bear with me for a little while longer. :D I know i SHOULD have this engine together and running by now but my gaskets arent here yet so that puts a damper on it. I have a 1985 atc250r engine with a trashed LEFT side engine case. I also have an 89 250r engine with a broken RIGHT engine case. I have discovered that it seems a lot easier to switch the left side case rather than the right side case. My question is, could i just take the left case, crank and top end off of the 89 engine and bolt it right up to the 85 engine? If not im going to have to pull the right side engine case off of the 85 and put it on the 89.

[jason85atc250r]

yep just pull the left one AKA flywheel side from the 89 motor. sit it on the side when you pull it and you can leave all the tranny gears in the right case plus the crank in your 85 motor. thats the easiest way.

but the 89 has the long rod crank with using a 86 and older piston with a spacer plate it'll really rip. 89 have a better clutch setup also so switch the clutch basket and everything related from that engine and put in into your 85 motor

[hrc85250r]

i would just throw the good side on the 85 onto the 89 motor.

[dizasterzrfun69]

yep just pull the left one AKA flywheel side from the 89 motor. sit it on the side when you pull it and you can leave all the tranny gears in the right case plus the crank in your 85 motor. thats the easiest way.

but the 89 has the long rod crank with using a 86 and older piston with a spacer plate it'll really rip. 89 have a better clutch setup also so switch the clutch basket and everything related from that engine and put in into your 85 motor


well the 89 doesnt have a clutch assembly unfortunately. The 89 does have a cool head and a ported jug. So are you saying use the whole 85 top end? or just the piston with a spacer plate and the 89 cylinder? USE the 85 or 89 crank?? I'm lost in this whole liquid cooled R thing:rolleyes: sry. I'll i've had for R's are the air cooled engines. From what i understand though you want a long rod correct? Well i hope so because thats why i bought the 89 engine. I need someone to clear up this whole long rod/ short rod/ spacer plate stuff. I know the 87 and newer has a long rod and you have to use a spacer plate on the 87 and newer engines if you use a 85-86 top end. thats about all i know though. someone help ....

[dizasterzrfun69]

i would just throw the good side on the 85 onto the 89 motor. thats what i might end up doing. I just figured if it was basically the same thing and easier then why not just switch the left side cases and crank? i'm slowly learning about the Liquid 250r's.......

[200x Basket]

here is a post i made a few years back. it really is simple.

http://www.3wheeler.org/vb/showthread.php?t=6218

[jason85atc250r]

well the 89 doesnt have a clutch assembly unfortunately. The 89 does have a cool head and a ported jug. So are you saying use the whole 85 top end? or just the piston with a spacer plate and the 89 cylinder? USE the 85 or 89 crank?? I'm lost in this whole liquid cooled R thing:rolleyes: sry. I'll i've had for R's are the air cooled engines. From what i understand though you want a long rod correct? Well i hope so because thats why i bought the 89 engine. I need someone to clear up this whole long rod/ short rod/ spacer plate stuff. I know the 87 and newer has a long rod and you have to use a spacer plate on the 87 and newer engines if you use a 85-86 top end. thats about all i know though. someone help ....



i would just put the 89 case half and long rod crank into your 85 bottom end since the 89 is missing parts. since the clutch stuff is missing that the only part thats really makes the 89 bottom end better.

then you 'll be using the 89 ported cylinder and cool head with a 85 style piston and the spacer plate. the cylinder interchange with either style piston. then you'll be really ripping it up:D

[jason85atc250r]

i would just put the 89 case half and long rod crank into your 85 bottom end since the 89 is missing parts. since the clutch stuff is missing that the only part thats really makes the 89 bottom end better.

then you 'll be using the 89 ported cylinder and cool head with a 85 style piston and the spacer plate. the cylinder interchange with either style piston. then you'll be really ripping it up:D

pm me with your phone number and i'll call you and explain it over the phone if that helps. i have free long distance on my cell.

[jason85atc250r]

i would just put the 89 case half and long rod crank into your 85 bottom end since the 89 is missing parts. since the clutch stuff is missing that the only part thats really makes the 89 bottom end better.

then you 'll be using the 89 ported cylinder and cool head with a 85 style piston and the spacer plate. the cylinder interchange with either style piston. then you'll be really ripping it up:D

pm me with your phone number and i'll call you and explain it over the phone if that helps. i have free long distance on my cell.

[grundlegrabber]

Jason explained it pretty well with the long/short rod deal. The cases are the same through the years. But while you have them split, check the tranny gears and shift forks real good for wear/damage. Those R trannies take a beating, pieces break off the gears. Save ya a lot of time if you catch it now while it's apart!

[88 Turbo Coupe]

Can you see the spacer plate between the cases and jug on a complete engine?

[dizasterzrfun69]

Can you see the spacer plate between the cases and jug on a complete engine?


actually i dont think either of them have a spacer plate. They are both about 30 minutes away at my old mans house otherwise i'd go look.

[Pete]

I wouldn't run an 86 style piston with a spacer plate on the 89 rod and topend. It increases the crankcase volumn and makes the engine lazy. Reed spacers do the same thing. If you want to tame down the power, then by all means.

All you have to do is to remember to match your piston choice to your crank. If you have an 85 or 86 short rod crank, run the 85/ 86 style piston. If you have the 87+ style crank, then run an 87+ piston. It does not matter what year of cylinder or cases you have.

Do keep in mind if you do some mixing and matching, 5th gear is 1 tooth taller on the early year transmissions, so I wouldn't mix and match the trannies, use them as a whole assembly.

[Pete]

Can you see the spacer plate between the cases and jug on a complete engine?

and yes, when you run an 86 style piston on an 89 crank, you CAN see the spacer plate. I've had a setup like this before.

[dizasterzrfun69]

I wouldn't run an 86 style piston with a spacer plate on the 89 rod and topend. It increases the crankcase volumn and makes the engine lazy. Reed spacers do the same thing. If you want to tame down the power, then by all means.

All you have to do is to remember to match your piston choice to your crank. If you have an 85 or 86 short rod crank, run the 85/ 86 style piston. If you have the 87+ style crank, then run an 87+ piston. It does not matter what year of cylinder or cases you have.

Do keep in mind if you do some mixing and matching, 5th gear is 1 tooth taller on the early year transmissions, so I wouldn't mix and match the trannies, use them as a whole assembly.

Well like i said, the 89 top end has some porting done to it already and a cool head, i'm also planning on a cr reed cage and reeds.