Bike runs well and then dies at full temp and wont start.

[WeeMan]

I set out this morning to bed in my new bore kit a little more. I was riding for about 5 minutes maybe a mile or so taking it steady when the bike just died on me. It was running well before and just stopped. When I tried to start it again it just turned over but did not fire. I wheeled it home and put it back in the garage out of frustration. Not to be beaten I went back about an hour later and tried to start it. It fired up straight away and ran fine again. Does anyone know what the issue could be? It seemed to die at full temp.

Could it be the Bystarter or could it be a dodgy reed valve? The carb and airbox are standard and the only changes are a 65cc bbk and a SP3 exhaust. Its jetted up to #90. Its an AF05 engine.

I don't want to go far now in case it does it again.

[abreen89]

Its NOT the bystarter or reeds... did you heat cycle your new BBK? are you adding extra oil to the tank for break in? what brand spark plug are you running? Did it just shut off like you flipped the kill switch or sputter out?

[WeeMan]

Im running an NGK spark plug which is in good condition. I have not added oil to the tank as it seems to be a bit rich any how judging by the smoke form the exhaust. It just shut off like I'd shut off the kill switch. Not sure what heat cycling is but I did run it on the stand til warm and then shut it off every day for about 10 days.

I've been really careful during break in and still am doing. All help is gratefully appreciated.

[Trafficjamz]

Im running an NGK spark plug which is in good condition. I have not added oil to the tank as it seems to be a bit rich any how judging by the smoke form the exhaust. It just shut off like I'd shut off the kill switch. Not sure what heat cycling is but I did run it on the stand til warm and then shut it off every day for about 10 days.

I've been really careful during break in and still am doing. All help is gratefully appreciated.

Do you still have the restrictor in the sp3 exhaust?

You might have softsiezed you engine.

did your scooter run well before the 65cc kit?

[WeeMan]

I took the restrictor out of the exhaust. It ran ok before the BBK but when i replaced the old cylinder and piston it was very scored and the rings were worn. It also ran ok when I had the BBK and the standard exhaust. It does seem that it started with the SP3 to be fair which could be because it is revving higher but I have only run it at 1/2 throttle as I was scared of killing the BBK.

[abreen89]

Im running an NGK spark plug which is in good condition. I have not added oil to the tank as it seems to be a bit rich any how judging by the smoke form the exhaust. It just shut off like I'd shut off the kill switch. Not sure what heat cycling is but I did run it on the stand til warm and then shut it off every day for about 10 days.

I've been really careful during break in and still am doing. All help is gratefully appreciated.

if you didnt just add ure bbk i would suspec electrical (iv had that problem) But since you just installed the bbk im thinking soft seize. do a compression check

[WeeMan]

What is soft seized? I did a compression test last week and it was about 135psi wot and warm. How much damage can a soft seize do?

[abreen89]

a soft seize is like a seize but doesnt stop completely but it can ruin your piston and cylinder.. Good if you know that it was 135psi before the problem retake it now if its alot lower you need to pull the head.

[WeeMan]

Yep Ill do another check and see. Is it worth adding some oil to gas to make sure if anything its over lubricated?

[abreen89]

Yep Ill do another check and see. Is it worth adding some oil to gas to make sure if anything its over lubricated?

at this point its probably too late when you install a new bbk you should always add oil to the tank for the first few tanks running rich doesnt hurt

[veedubh20]

from the old bore that you had. get rubbish in the crankkcase. since then. new bore.

get metal shaving in the crankcase splash oil/ metal shave will get piston seize..

crank case must clean out and flush the metal shave out wit clean gas and carb cleaner.

[abreen89]

from the old bore that you had. get rubbish in the crankkcase. since then. new bore.

get metal shaving in the crankcase splash oil/ metal shave will get piston seize..

crank case must clean out and flush the metal shave out wit clean gas and carb cleaner.

[veedubh20]

from the old bore that you had. get rubbish in the crankkcase. since then. new bore.

get metal shaving in the crankcase splash oil/ metal shave will get piston seize..

crank case must clean out and flush the metal shave out wit clean gas and carb cleaner.

here what he said!

when i replaced the old cylinder and piston it was very scored and the rings were worn.

the old stock piston got scored in the cylinder.

just because tiny little metal shaving fell into crankcase, when the cylinder jug off. .

that mean he didnt remove the motor off the scooter.

you cant see with the eyes into the crankcase



if the motor was seize on the stock bore.. will you install a new big bore kit. the answer is NO!

crankcase need to clean up good. add clean gas into crank case. before turn the motor upsidedown. spray carb cleaner.

[abreen89]

from the old bore that you had. get rubbish in the crankkcase. since then. new bore.

get metal shaving in the crankcase splash oil/ metal shave will get piston seize..

crank case must clean out and flush the metal shave out wit clean gas and carb cleaner.

here what he said!

when i replaced the old cylinder and piston it was very scored and the rings were worn.

the old stock piston got scored in the cylinder.

just because tiny little metal shaving fell into crankcase, when the cylinder jug off. .

that mean he didnt remove the motor off the scooter.

you cant see with the eyes into the crankcase



if the motor was seize on the stock bore.. will you install a new big bore kit. the answer is NO!

crankcase need to clean up good. add clean gas into crank case. before turn the motor upsidedown. spray carb cleaner.

Yes this could be your problem... Check compression first if its lower then your first number pull the head and check for what veedub said...

[Bear45-70]

Im running an NGK spark plug which is in good condition. I have not added oil to the tank as it seems to be a bit rich any how judging by the smoke form the exhaust. It just shut off like I'd shut off the kill switch. Not sure what heat cycling is but I did run it on the stand til warm and then shut it off every day for about 10 days.

I've been really careful during break in and still am doing. All help is gratefully appreciated.

Do you still have the restrictor in the sp3 exhaust?

You might have softsiezed you engine.

did your scooter run well before the 65cc kit?

I think he did more than soft seize it. Compression check first.