Corsa Confused

[SpamMusubi4Life]

What is this? Is this a seize? I was traveling long distance and after I put in new 7.3 gears I went on the freeway after ten minutes the motor just died. S H I T! After stopping for a minute or two I tried to start it. It fired right up with no problems. Kept idle and throttle response was good. After returning home I took apart my head. Found these markings but they are smooth as can be. Not sure what they are but the bore still has cross hatches so Idk if its still not broken in? I put over 400 miles on the new bore. Please let me know what are these markings? I seized my 66 and after waiting for it to cool it wouldn't start for s h I t. So Idk if the polini has seized seeing how it fired up right after it died.???

[SpamMusubi4Life]

?

[Mystic]

looks like a light seize from maybe an exhaust leak since it is primarily on the exhaust side since that is the side that gets hotter. What compression and octane fuel are you using? The corsa is around 155psi and suggests using 95 octane, most people add a head gasket to lower the compression so it will run pump gas. Also with the taller gears your rpms are lower but the strain on the motor to push the taller gears is greater

[SpamMusubi4Life]

Well using Lucas 2t mix put six caps to every dollar of premium gas. 93 octane? I figured it was a seize. I just bought this and its my only way of getting to work which is over the freeway uphill and down. Maybe I should port it to give it a little more power to get me up hill no problem.

[LMH]

Definite seize, corsas are tough but keep running like that and its over. If you pull your piston you will see the marks also. Find your leak.

[LMH]

I dont recommend lucas semi synthetic at all.

[SpamMusubi4Life]

Thanks

[LMH]

http://www.amazon.com/Hopkins-10111-2-C ... B000G72U0K
best thing to have in your "trunk"

[Mystic]

easiest thing to do is add that head gasket to lower the compression. No need to port the block on the corsa since it is only a tiny difference in the boost port sizes, porting the intake might help but you gotta split the cases for that. Since you are in hawaii they gots all the stuff you need. Just get a minarelli 47mm headgasket and try that. I have no idea how much oil that is hahhaa mix 4 oz to the gallon to get 32:1. I use Lucas performance myself and have never had a problem with it and make sure the exhaust is sealed

--also you might want to get a trailtech tto CHT gauge so you can monitor the temps, jet rich on the bottom that way if the temps get too high you can just slow down lol

[veedubh20]

there are many ways new bore can seize...

not follow the polini recommend break in piston.

not 100% fully synthetic oil.

premix raito just screw up! capful by dollar. *!
Correct premix ratio get a squezze bottle at moped shop.

dont go on freeway, piston not broken in..

old bore was sieze before, put new bore kits in.. you get metal shaving in crankcase oil lube splash metal rubbish. Need to clean up real clean in the crank case....

lack of block porting..

[kingkamehameha]

I suspect poor tuning and failure to do a pressure test. Just because theres markings on the exaust side doest mean thats where the leak is coming from. If i were you i would do a light hone on that thing. Also read up on proper plug chops and how to tune your carb. I wouldnt be running it on the freeway unless i was 100% sure my jetting is where it needs to be. A cht gauge isnt nessisary but it helps alot with tuning. Making sure your fan shrouds are all tight helps from over heating. The general rule for 72cc gearing is 7.6:1 ratio is the tallest you can reliably go. 8:1s is a good choice and remember the corsa loves high rpms so dont be afraid to use the shorter gearing. Its not the rpms that fry the bore its improper tuning and improper set up on the trans. Make sure to add that metal headgasket predetonation will kill it

[SpamMusubi4Life]

So bad tuning is the culprit. Man I really needa get this right. I wanna get a bigger carb, everyone says to run a oko 28 but after reading a few threads of right choice for a aftermarket carb, the oko is not what I want. I'm trynna find a 24mm Keihin, pricier than the oko clone but I have set my mind on it. A lot have said a bigger pipe is better too.

[kingkamehameha]

So bad tuning is the culprit. Man I really needa get this right. I wanna get a bigger carb, everyone says to run a oko 28 but after reading a few threads of right choice for a aftermarket carb, the oko is not what I want. I'm trynna find a 24mm Keihin, pricier than the oko clone but I have set my mind on it. A lot have said a bigger pipe is better too.

Corsa+scorpion=action. I run a 28 and im considering going down to a 26mm. You can tune a 28mm and it will work perfectly fine but your throttle response wont be as crisp as a smaller carb. With that being said with the 28mm you should be aiming for the range of 130-135 main and a 52-55 pilot. Remember you will need a cht to get the needle clip setting right and also start off with big jets work your way down. Better to foul 2 or 3 plugs than to ruin a 350 dollar bore.

[kingkamehameha]

Yeah and dont forget your trans and pipe and port size have alot to do with jetting

[SpamMusubi4Life]

Those jettings for a 24mm?