Have I blown up my motor?

cyclepro101 · Jul 7, 2009

Thanks, I took the motor back and he said he has seen this type of failure before, he said it was poor chrome plating on the barrell. He sent the photos to China and depending on what they say he will either give me a new motor or replace the head, cyclinder and piston. I hope I just get a new motor as all that metal crap was all through the bottom end.
He also thinks the 50cc motor is a better motor. A lot smoother and runs a lot better. A bit down on power but still tops out about the same as the 66cc. I will see how this goes but. I dont hold out much hope if he is just going to replace the parts. He said if he has to replace the parts he will have to flush out the bottom end with kero. I just hope he puts new rings on the new piston if it goes that way. But I am sure he wont be bothered with all that and I think he will just give me a new motor. And next time I wont flog it like a raped ape

Steve

Echotraveler · Jul 7, 2009

Respuesta: Have I blown up my motor?

hey cycle,

Thanx for posting your problem here man. Mine doesn't scream. im tryint to make it scream a bit lol not like that ....

Technocyclist · Jul 7, 2009

I also got my engine from the same dealer... It got blown after 3 months, I think it was an airleak that caused it.

Dealer did not replace it...

I still got my 2nd engine from the same dealer and replaced the cheap gaskets with garlock. Then oil seals keeps popping out... I reinforced the oilseals with some gasket maker on the edges. Seems to work ok for now... for how long??? I dunno... Have to find some good oil seals, probably lock it with some circlips or something...

Sydneysider · Jul 7, 2009

thats looks pretty bad mate not much you can do when theres a manufacturing defect.. you know alot also depends on how you break in a new engine too, might be a bit overzealous but I still run in new engines well after the specified period as you gotta do the right thing by them.. so far Ive had no problems and every motor has been great.. even small issues like an airleaks will overheat and kill an engine fast.

Good Luck with your new one (^)

cyclepro101 · Jul 11, 2009

Sowho has a 48cc and who has he 66cc? It is appearing to me that the original engine was the 48cc and all the components are for that one. I just wonder if the 66cc is just too miss matched? From what I read the 48cc goes just as good if not better.

Steve

johnmartinwright · Jul 11, 2009

that looks nasty

cyclepro101 · Jul 13, 2009

Got the new engine. Well not a whole new engine, he just replaced the top end. So I guess I will need to run in again nice and easy. But I will leave the 36 tooth sprocket on and and the SBP Pipe on just take it easy for the first couple of 1:16 tanks.

Steve

Bikeguy Joe · Jul 13, 2009

Don't run 16:1.

It is complete overkill, and can even cause a lean condition, and that will kill an engine.

Also, very important, When you start then engine, be sure it is warmed up at a high idle or slow cruise speed for the first couple of minutes.

Running a two stroke to hard right after start up can cause what is called "cold seizure" and it take the stuff off the cylinder or scuff the piston skirt at the very least.

Sydneysider · Jul 13, 2009

I agree with Joe..

Itll foul the plug and it will also ruin the engine with excessive deposits.

I start at 18:1 for the first 2 tanks at less than 20km/hr (letting engine cool a bit after 1/2 hour of riding), then use 20:1 for the next 4 tanks keeping the speed less than 25km/hr and taking breaks after 1 hour of riding.

After that I can safely use 25:1 but dont go faster than 25km/hr until I have burned about 10 tanks in total.

oh also, make sure that you use a lower ratio like 20:1 on warm days when summer comes around .. we know how hot it gets down here in Oz!

auflg

cyclepro101 · Jul 14, 2009

Good info fellas, thanks.
I also took this chance to grind off that botom bit of the piston that covers the inlet port at TDC. I dont know how much diff it will make, but I am going to take it very very easy.

cyclepro101 · Jul 15, 2009

Wel guess what...................... its done it again. I put the new motor, or the one with the new top end on. It started first kick with loads of compression. I let it warm up for 5min. Loads of smoke as I am running 1:16. I then took it for a short ride for about 2mins then when I got home it conked out. Then I noticed that there was not much compression. So I took the head off and although it was not as bad as the first head and barrell it was going to end up the same. I suspect that there was still some crud in the bottom of the engine and it got into the top.
I have sent an e-mail with photos off to the retailer, I hope he comes good with a new motor or at least let me buy a new one at cost.

Steve

Bikeguy Joe · Jul 15, 2009

16:1?
TOO MUCH OIL.

That looks like a different kind of failure.

That looks like the wrist pin keeper or other parts came loose and got tangled up in the engine.

xlite · Jul 15, 2009

cyclepro101 said:
Good info fellas, thanks.
I also took this chance to grind off that botom bit of the piston that covers the inlet port at TDC. I dont know how much diff it will make, but I am going to take it very very easy.

Maybe not a good idea to screw with these engines before you get them running.

cyclepro101 · Jul 17, 2009

Well good news. The fella who sells these things here in Aus, is going to replace the entier engince for free. He suspects that there was still some metal bits left in the bottom of the motor when he replaced the pistion, jug and head.
Just lucky I would say.

cyclepro101 · Jul 31, 2009

Well well well, I have the complete NEW motor fitted now and WOW. If u look back through all my previous posts I was always asking why my motor was so slow and noisy. Well the new motor is tops. I have not put the SBP pipe on it yet, I want to run it in a bit first. But with the 36t sprocket it revs just above idle and does 30km's. Loads more compression than my first motor ever had. I will run the first 2 tanks at 1:16 then go to 1:25 and then put the pipe on, and then leave it alone.

Steve

Mike Hunt · Jul 31, 2009

how can you tell if you have good or bad compression?

cyclepro101 · Aug 1, 2009

Well the first way I can tell is that I cant push this one around with the clutch out. 2nd, theres a lot more pressure coming out the pipe, also it starts so much easier, first crank. I now start my bike by lifting the back wheel and kick starting it like that and letting it warm up prior to riding. As I have to go up a big hill to get out of my place I fear I could of damaged the cylinder that way last time.

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