My 89 engine needs rebuilt.....

Doppler · Post by **Doppler** » January 2nd, 2012, 2:43 pm

Engine took a crap while cruising down a dirt road.
Ive finally checked it all out....
NEEDS:
Piston, 91mm I already have
Crank, no up&down play but side clearance measures .060"

WANTS:
39.5mm PWK

WILL ALSO REPLACE:
Crank bearings, they are fine w/ no play but i will do anyway
Crank seals
All bottom end seals
All engine gaskets

MAYBES:
Gearbox bearings
Clutch
I havent checked these out as the bottom is still together but had no issues while riding.

What do i NEED to do to make the 91mm top end work? What cyl/ head machining has to be done? Who can do a quality job without breaking the bank? Will port timing be different with bigger bore causing top end loss? This bike already has a weak top end.
Any porting recomendations for a desert/ hillclimb/ trail bike?

Any info will be appreciated.

Post by **AlisoBob** » January 2nd, 2012, 4:31 pm

I think service max listed in the manual is 0.040". Your at 0.060" side play with zero up/dpown play?

Run it..... with lots of oil.

Doppler · Post by **Doppler** » January 2nd, 2012, 5:08 pm

Serious? That would be great news if i can use the crank.
I just thought max was max

Post by **AlisoBob** » January 2nd, 2012, 6:03 pm

Its a dirtbike dude..... not a Lear Jet.

If you ride it 30 hours a year, I'll be shocked...

100hp honda · Post by **100hp honda** » January 2nd, 2012, 6:52 pm

i see bobs point but on the other hand all the parts are fairly cheap. if your unsure how long since that engine been rebuilt i would just spring for all new stuff. hard to say but its very possible them bearings are original. maybe not but its possible. split the cases and get all the bearing numbers then call a local bearing shop for prices. might be cheaper than going through honda. rod should be no more than $100. seen some for $85 on ebay i think. about $100 to have someone to install it. you already got the piston so your good there. about $60 to have it bored. couple bearings in the trans you need a puller. dealer or local shop should do it for $25. check trans gear cogs for wear. check gear bushings, should be a spec in the manual. im sure alot of stuff will be reusable but just start checking shit from top to bottom

Post by **AlisoBob** » January 2nd, 2012, 7:05 pm

Roosty, whats the biggest rod side clearence you've seen run, without tearing shit up?

100hp honda · Post by **100hp honda** » January 2nd, 2012, 7:31 pm

im not one to care about side play but .060 is far too excessive if it were my engine. put in new cranks at .030 but thats a far cry from .060. more importantly is how did it get to .060 ? 15years of wear and tear i would imagine. rod bearing probly seen better days also. i suppose theres a slim chance its a newer crank assembly and the shop just put it at .060 for some unknown reason

100hp honda · Post by **100hp honda** » January 2nd, 2012, 7:38 pm

hold the bottom of the rod stationary against one side of the crank wheels. push the top of the rod the opposite way. bet that fuckers sloppy as shit

Doppler · Post by **Doppler** » January 2nd, 2012, 9:33 pm

I'm going to ride it 31 hours just to shock you

Post by **AlisoBob** » January 3rd, 2012, 8:56 am

I spoke with a famous Inuit CR500 engine builder this morning who said he's seen brand new Honda cranks come out of the wrapper with 0.050" side clearence before...

If the thing was popping out of gear, you gotta' split the cases...

If the crank bearings sounded like a old cement mixer.... you gotta' split the cases

If the piston shattered and threw trash everywhere, you probably should split the cases...

But to split them just to swap out the rod thrust washers..... I'd chance it.

Push the whole stack to one side, then look at the outboard side of the washer, then slide it over to look at the inboard side. Repeat for the other washer.

If they dont show signs of distress, chipping, uneven wear,discoloration or other abnornal wear..... I'd run it.

Its up to you to make your own decision.

Nodge · Post by **Nodge** » January 3rd, 2012, 10:30 am

AlisoBob wrote:I spoke with a famous Inuit CR500 engine builder this morning who said .

I seriously just about choked on my coffee just now, Bob.
Thanks!

Doppler · Post by **Doppler** » January 3rd, 2012, 11:55 am

Ok I will definitely check out the thrust washers and see how they are.
Luckily I didnt have any of the problems you mentioned. The only reason that I was going to split and rebuild was from the out of spec side clearance.

Doppler · Post by **Doppler** » January 3rd, 2012, 3:31 pm

Re-checked with my good set of feeler gauges and its at .052 but thrust washers show no signs of wear. All the little oiling dimples on them are even.

Post by **AlisoBob** » January 3rd, 2012, 4:02 pm

It was prolly 0.050" new...

100hp honda · Post by **100hp honda** » January 3rd, 2012, 5:38 pm

doesnt matter either way because this whole subject is just a matter preference. still pretty funny and alittle odd your talking for someone else that is 100% capable of speaking on their own behalf. they were asked a question and never answerd but rather it seems a secret phone conversation took place

. next new crank anybody runs across with .050 side play get a pic. always interested in seeing new stuff

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » January 3rd, 2012, 6:07 pm

I didn't get to this thread yet Clyde, It was actually .055"

Having come from ancestors of Scotland and England I was waiting for someone with an Inuit background to chime in

Post by **AlisoBob** » January 3rd, 2012, 6:43 pm

100hp honda wrote:.....pretty funny and alittle odd your talking for someone else that is 100% capable of speaking on their own behalf. they were asked a question and never answerd but rather it seems a secret phone conversation took place .

Clyde, while your sitting around on unemployment..... Roosty is running his Dad's engine shop, working the farm, and planning a trip to Cancun thats less than a week away. He's a pretty busy guy.

The Inuit thing is a joke we both saw on Tosh.0. last week.

Thats on cable, so I know you dont watch it.

Your such a dum-fuk sometimes.... like all the time.

100hp honda · Post by **100hp honda** » January 3rd, 2012, 8:26 pm

Roostius_Maximus wrote:I didn't get to this thread yet Clyde, It was actually .055"

Having come from ancestors of Scotland and England I was waiting for someone with an Inuit background to chime in

ill take your story as true. however im thinking it was a rare occurance. double headed pennies can be found also if you dig hard enough. dopplers best interest would be to send his engine to a qaulified mechanic such as your self with proper equipment

bob while your on the dumbfuk subject let me link you to what is arguably the biggest head scratcher posted by anybody on a internal combustion forum since the invention of internet. for a recap if anyone forgot: bob suggest i was a idiot for pouring oil in the head for figuring volume and proceeded to flap his lips about how they got this new thing called math that would make it much easier and faster. unfrikin believable anyone would suggest such a idea but leave it to bob to do the unthinkable. heres your jackass of the century award bob :aholebadge:

read on for alot of laughs. bet even roostious shook his head in disbelief at few things bob said
http://www.bannedcr500riders.com/board/ ... 22&start=0

Post by **AlisoBob** » January 3rd, 2012, 9:03 pm

100hp honda wrote:...even roostious shook his head in disbelief at few things bob said

Roosty posted this...... in reference to you.

Hahahahahahahahahahaa!

Doppler · Post by **Doppler** » January 3rd, 2012, 9:52 pm

I may not know all the ins and outs or specs and what needs machining on the cr500 100hp, but I've rebuilt several bottom ends in my life and am surely qualified to do my own work other than machining of course. I don't have a machine shop.

100hp honda · Post by **100hp honda** » January 3rd, 2012, 9:53 pm

bob quit living through other people. you did it with gss glen and now roostious. grow a pair and stand on your own. i realise you probly want to be like a few of the smarter folks around he but damn dude, atleast dont make it so obvious. maybe you wish you were glens son ? hell i dont know

Post by **AlisoBob** » January 3rd, 2012, 11:17 pm

Your right, I want to be a unemployed snow plow driver who lives in a storage unit and blow all my money on hookers and blasting up 2% grades on shitty running bikes, videotaping myself while wishing I was Dusty Beer.....

Oh wait, I just described you.

[youtube]http://www.youtube.com/watch?v=YNofYBru ... e=youtu.be[/youtube]

Yes, this really Clyde taping himself.....

mr500 · Post by **mr500** » January 4th, 2012, 2:23 am

You boys must be related?
I fight with my brother like that ...

Post by **AlisoBob** » January 4th, 2012, 8:07 am

THAT was a low blow...

scooter5002 · Post by **scooter5002** » January 4th, 2012, 8:45 am

So what's the problem with the HOOKERS, Bob?

BannedCR500Riders.com

My 89 engine needs rebuilt.....

My 89 engine needs rebuilt.....