Honda Spree and Elite 50 Forums

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!

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

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

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?

fujio001 wrote: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.

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?

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

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

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