Soft Seizing Sym

[fujio001]

Just got a new Sym DD50. Prior to leaving the shop I had the guys at the shop upgrade the engine to a 66cc big bore kit. They changed a few other things to include the variator and V8 exhaust.

On the way home the engine soft seized after 20min of riding. After about 5 min of cooling it started up and rode just fine. I brought it back and they "fixed" it.

With less than 100 miles on the scooter it happened again. I was riding on a long stretch of road at 35mph for about 20min when it seized again.

Since it rides and accelerates great and only seems to occur after riding for a while, could it be the oiling system? BTW, I am using Bel-ray SI-7.

Has this happened to you guys? Should I have the shop replace the piston/body?

Thanks in advance!

[maddog]

I hope you changed the gear ratio and added at least a 1/2 oz of oil in the fuel tank.

[kingkamehameha]

Change gears to 9:1 ratio at least and run premix. You didnt say anything about a carb upgrade or premix. Sounds like this shop is ripping you. Also a new bore needs a heat cycle and 50 miles of riding with no load to seat the piston rings and 400 miles of low rev riding to break in the kit

[fujio001]

The carb and jet was also changed. To prevent it from happening again I added a couple ounces of oil directly to a full tank of 92 octane. No more issues. I am riding no faster than about 35mph for now. Currently at about 150 miles. I now see the value of having a temperature gauge. Any suggestions for a good shop in the Honolulu area?

[Cherreh SR]

The carb and jet was also changed. To prevent it from happening again I added a couple ounces of oil directly to a full tank of 92 octane. No more issues. I am riding no faster than about 35mph for now. Currently at about 150 miles. I now see the value of having a temperature gauge. Any suggestions for a good shop in the Honolulu area?

Its been a while since I went to a shop back home but I think it was frank at quik fix who did my first bore kit. Was a relatively small shop on a back street, looked a little iffy but tried them out and they set me up very nice! Also had them install a strokes crank later and they did an excellent job then too.

[fujio001]

Aargh! It soft seized again. I was running about 1/64 premix and the stock oil pump. Could it be I am running too lean?

[fujio001]

After reading several other threads, could the main jet be too small leading to overheating and seizing?

[kingkamehameha]

Put a 21mm carb and make sure its not leaking any air from anywhere. I would upgrade your gears to a 9:1 ratio. Your bore isnt broken in and sounds like your trying to max it out

[fujio001]

The slightly larger carb makes logical sense however I do not think I am maxing it out 35mph even if the gears are stock.