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Older engines Vs. New?
Posted: October 14th, 2009, 7:48 am
by RedtillIdie
Hello, I am new here, I am just getting into the CR500 club, I currently do not have a CR5, but I do have a 2006 CRF250X all modded out. I obviously have a lot of questions about the CR5. I was wondering if it is true that the older CR5 motors were more powerful and "faster" than the new ones because they cut down the power on the new ones?
Thanks guys, ride on!
Posted: October 14th, 2009, 8:17 am
by AlisoBob
Yup..... try ride a '86 sometime.....

Posted: October 14th, 2009, 9:09 am
by RedtillIdie
AlisoBob wrote:Yup..... try ride a '86 sometime.....

''
So the older ones like 86 and 90's are faster?
Posted: October 14th, 2009, 9:21 am
by AlisoBob
It was pretty much over by '88.... 89-01 is basically all the same
Posted: October 14th, 2009, 11:01 am
by RedtillIdie
AlisoBob wrote:It was pretty much over by '88.... 89-01 is basically all the same
The older ones are also close ratio which isn't that great for trails am I correct...?
Posted: October 14th, 2009, 11:53 am
by AlisoBob
Yea, and theres corrosion, clutch, electrial and other issues with the early ones.
Stick with something '94 or later
Posted: October 14th, 2009, 12:58 pm
by dannygraves
'85-'87 were wide ratio, '88-'92 close and '93+ wide again.
'89 was a wicked motor, it had smoother power delivery than the '84-'86 becasue of the long rod introduced in '87. '87-'89 were the fastest. the earlier ones had rediculous power and it came on instantly like an electric motor, but they didn't rev worth a damn, so in a race a '87+ will win against an '85 or '86.
'89 was the best IMO because it had the '85-'89 porting with the larger ports, etc. put it was the newer platform, so it suits a conversion easily, it had the larger swingarm bolt, the water pu setup for the newer styly pipe, the newer kicker, etc. It had the older clutch, with can help in a conversion since the clutch cover is shorter and gives more brake lever clearance and it uses the newer head and head gasket.
the only down side is the close ratio, which can be swapped, I did on my gen-3
don't get an old motor specifically for the power delivery, the newer ones are nicer to ride and honestly are faster in a race and less likely to leave you sitting on your ass. if you do an old motor because thats what you have, or you got a killer deal, then enjoy white nuckling and sucking seat foam in your ass while screaming like a little girl!

Posted: October 14th, 2009, 1:04 pm
by dannygraves
'93+ are best overall, imo, but '93 was still black cases, '94+ are all the same.
Posted: October 14th, 2009, 1:53 pm
by Roostius_Maximus
dude, read my "tech post" link at the bottom of my posts, all the interchange stuff there, basically shows the evolution from wicked to trail bike, what stuff lasted + what had to be beefed up
I'd spec a new engine like this:
1986 short rod
1989 jug with porting
1998-01 trans gears
wide clutch assembly with heavy springs
250 ignition
fatty pipe
pwk
head cut for more compression
i'm only a short rod away from that in my gen3
probably going to build a 525 with a short rod in modified 90 cases with a 90 trans 88 head+ 89 jug. all the parts are sitting on the shelf, just gotta find time to get it put together

Posted: October 14th, 2009, 2:01 pm
by dannygraves
thats funny because I put a long rod in my '86 and prefered the performance with the long rod.
Posted: October 14th, 2009, 2:01 pm
by dannygraves
everything else I agree with %100
Posted: October 14th, 2009, 2:09 pm
by AlisoBob
Robs '89 didnt feel any different than my '97 powerwise...... except the close ratio tranny killed the top end.
Posted: October 14th, 2009, 2:11 pm
by Roostius_Maximus
i'm going to say its way easier to ride the long rod engines, the short rod one in my '88 is so dammn rangy its hard to know where the power is coming in, but when its extended for on the hill its revvedup for clutch dump anyways. I know that if i want a good scare i get on the field with that bike and no extention. i might hate the short rod in an AF, but it should be tried, and then i can switch the 525 jug to a long rod + tall deck case if i need.
Posted: October 14th, 2009, 2:12 pm
by dannygraves
didn't he replace the jug with new? they used the new part number to replace it. a lot of '89s have '90+ jugs on them. the intake port was atleast 10mm wider and the boost ports shaped way different. and a wider exhaust port. that is why the '89 calls for the old piston, the cutout in the older pistons was wider.
Posted: October 14th, 2009, 2:15 pm
by dannygraves
I did notice fewer looping situation after I swapped rods and I got more rpm out of it. then again that motor was so wicked ported that its had to tell what changes did what.
Posted: October 14th, 2009, 2:30 pm
by Roostius_Maximus
i'd looped the bike + screwed a fender like immidiately
Posted: October 14th, 2009, 2:34 pm
by AlisoBob
Did you do a burnout on your chin... like "You know Who"?

Posted: October 14th, 2009, 2:42 pm
by dannygraves
for the record, it was a burnout across my face! and it ripped my chest protector off!
You should have seen me as a kid, before I grew into my ears, I looked exactly like the mad guy.
Posted: October 14th, 2009, 2:47 pm
by Roostius_Maximus
my bro had a wreck on a friends cj360t, smoothest tire ever tore his shoe off and laid rubber on the top of his foot, it was like 10 years ago now and you can still see the mark
Posted: October 14th, 2009, 3:04 pm
by dannygraves
awesome!
Posted: October 14th, 2009, 5:53 pm
by 100hp honda
Roostius_Maximus wrote:i'm going to say its way easier to ride the long rod engines, the short rod one in my '88 is so dammn rangy its hard to know where the power is coming in, but when its extended for on the hill its revvedup for clutch dump anyways. I know that if i want a good scare i get on the field with that bike and no extention. i might hate the short rod in an AF, but it should be tried, and then i can switch the 525 jug to a long rod + tall deck case if i need.
gave up on the ktm idea ? i have 2 honda in the corner of the garage but i aint even messing with them, im putting all my money and time into the 550.........its going to be a ground pounder

Posted: October 14th, 2009, 9:03 pm
by nmdesertrider
don't listen to these guys they got sandy pussy. I love my 85 and wouldn't change a thing.
Of course I had to replace the entire transmission, clutch, clutch cover and ignition components to get it working ok.
Posted: October 14th, 2009, 9:30 pm
by CR500R7
dannygraves wrote:You should have seen me as a kid, before I grew into my ears, I looked exactly like the mad guy.
Did you have the "sideburns and glasses" then.
If I removed the bridge from the exhaust port ( make it like an 84 exhaust port ) on an 01 jug with stock porting what would I affect by doing it.
Would it stuff up the performance, kill reliablity or create something bad that I don't need?
Posted: October 15th, 2009, 3:36 am
by bearorso
With the references to a 525 & a 550 in this thread, could some one offer some advice on stroking my CRE.
By the time next years 4 day is over, if I enter & survive ( it may be local to me, so it will by my final fling @ the 4 day before my knee replacements) , I'll be at the point I promised myself I'd do a bottom end rebuild.
What I'd like to do is, if possible, use the earlier short rod (4.8 /5mm shorter?) and stroke the crank / relocate the pin, by the same amount, thus getting a square bore/stroke of 89 / 89(?). Of course, there may well be no room in the cases to go this far ( pretty sure that is so - I've seen the crank case mods Glen @ GSS did for his 700(?)cc CR) - if that's the case, I would not bother. But if possible, I think it would make for a very nice motor, even more of a tractor than it is now, with minimal extra expense over just a std bottom end rebuild - stroking the crank itself is no problem , nor expense to me. I am aware that piston skirt/ ports etc will /may need to be modified, but am aiming to get the same head height / piston deck height as std.
I don't have a spare motor anymore to pop apart & play with - that went into the last AF I did, so any advice as to if this stroking idea is viable, without cutting & shutting the case ( I could do that, but not interested enough to go that overboard) would be of great help.
Roostius - what do you reckon?
Bear
Posted: October 16th, 2009, 6:56 pm
by JR650
after getting it kinda dialed in, my gen 3 with 85 motor has a pretty crazy hit and a real problem keeping the front tire on the ground. definitely a violent ride sometimes, I love it. cant imagine why anyone would want more power without a longer swingarm. went on some wild mountain trails 2 weekends ago with some long steep climbs on rocks and that bike was a handful, gotta keep the revs down in tight stuff, when it comes on pipe it better be pointed in a straight line.