BannedCR500Riders.com

M.F.D.B. wrote:Thats definitely vacuum port as the reed block hasnt been drilled...

So chances are that this motor was running Nitrous? If so, are there any things in particular that I need to look out for?

As mentioned before it could be nitrous or an Alky motor. Either of which means it was run hard. If you dont know the history on a motor your only safe choice is buy all the gaskets and tear it down for inspection, in my opinion...

I definately planned on tearing it down if it was either alky or nitrous. guess I cant be too upset since I only paid $400 for a '98 engine. I saw the hole right away and questioned buying it, but I knew for that price it wouldn't be there long. He never ran it becuase it was for a TRX conversion that he never got around to doing for $ reasons and sold it to repair his rail that his son flipped on it's lid. so when I tear it down should I expect to see anything different? I am assuming that it should have some pretty wild porting right? I couldnt see if there was any porting cuz the exhaust port is all covered with burnt oil and I never pulled the reeds.

Im betting it was run on alky.

alky motor that wasnt purged. hope yours aint as bad

cast piston, i'd stil run it

is that jb on the kicker housing ? what a pile of crap

blasphemy!
who would disregard the king of dirt bike engines in such a manner.

may they be roosted by the IRC M5B of a 1000 CR500 bikes, on a crushed gravel road.... to the face or testicles.

is there not any love or respect?

prolly a crackhead

If that was an "alky motor that wasnt purged" it sure as hell had a bad left crank seal...

So i finally pulled the jug off my the engine and found there is no porting. why would there be a hole drilled to run a vacuum pump and not even have it ported? also, I noticed a couple lil cracks on the cases.

[/img]

those are tools marks. as in dremel tool. wasnt brits old motor was it ? . he once shaved a head with only dremel in hand. damn fine machinist he is

i have seen them cracked there, check by the base of the rear studs, it'll crack from the stator housing area thru into the crankcase IF its cracked up top, does looklike tool marks here tho

Those arnt "cracks", that happens when they cast things. Every bike I have ever had apart has those "shrink lines", dont worry. Also, 2 stroke jugs all have areas where the OEM does "touch ups" after the sleeve and jug have been cast together. Its not "porting" just flash clean up...

M.F.D.B. wrote:Those arnt "cracks", that happens when they cast things. Every bike I have ever had apart has those "shrink lines", dont worry. Also, 2 stroke jugs all have areas where the OEM does "touch ups" after the sleeve and jug have been cast together. Its not "porting" just flash clean up...

So I should just run it and not worry about it? i wasn't worried about the dremel lines at all.... just the cracks. are the dremel lines what you reffered to for "touch ups?" my jug still has the casting lines and it doesn't look live it has ever had a port or polish done. I am curious as to why they would have it set up for a vacuum pump and no other work done to the jug. although i do not have any experience with alky or nitrous bikes so that may be common... idk.

They arnt "cracks" think of them as "wrinkles" all the motors ive ever worked on have them. As far as the unmodded motor with a fuel pump, it could be a number of things. If the motor was destined for a cart many carting rules require alcohol as a safety issue. Even a stock 500 in a cart would be super fast so they may have decided to leave the motor stock for reliability. They may have intended to mod the jug but decided against it after the hole was drilled or ran out of money and sold the motor. All kinds of "maybe's"...I wouldnt worry about specualting...

Here is what mine looks like.

2strokeforever wrote:

Whats wrong with having a 500 on a kart?

nothing, other than it prolly gets the piss reved out of it all the time... it still could be taken care of tho, but if it wasnt
kinda like buying a 125 that was only rode in the sand dunes

IMO load and heat have more to do with it than rpm. I mean rpm will wear faster and is at a higher risk of running out of oil, but load is what creates heat. Brits cracked piston mobbed up a 1000ft sand mountain with the rear tire sunk halfway to the axle over and over and over. A kart gets prenty of load, especially with some sticky tires, but not the kind of stress a sand dune hill shooting bike sees.

dannygraves wrote: A kart gets prenty of load, especially with some sticky tires, but not the kind of stress a sand dune hill shooting bike with Britts fat ass riding it sees.

FIXED

dannygraves wrote: prenty ....

Your hanging out with Sara's mom too much.....