Seizing, but no damage?

jonah loshnowsky /

I just put a Puch high compression head on my 01 Tomos sprint. I was going about 40, and had been for a while, when the engine shut off and the bike came to a QUICK stop.

I was afraid it had seized so I kicked it over slowly, the engine turned over fine, with no noise, and good compression. I kicked hard this time and it started. I rode for another 10 min and it happened again. After that I rode straight home.

What could be causing this, I’m stumped. Once the bike is cool I’ll take the head off and look for damage.

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Re: Seizing, but no damage?

You soft seized. Take it apart and clean up the Piston and cylinder and you should be fine. You either got too hot, running lean or both.

Re: Seizing, but no damage?

Probably Fred /

> Stephen Simmons Wrote:

> -------------------------------------------------------

> You soft seized. Take it apart and clean up the Piston and cylinder and

> you should be fine. You either got too hot, running lean or both.

Yeah I blasted a puch Polini kit on a puch e50 during mid 2000s that had 15mm bing carb, 6p pipe to the bottom of a half mile long hill going around 64 mph at the bottom, when I got to the bottom there was a stop sign I stopped and the the engine stopped running and it was locked,

I went to kick it over and it was stuck so I waited a bit then a minute later I heard a clink meaning it released, I kicked it over and it rode home, it ran fine !

When I got home I took it apart expecting the worst and found nothing except maybe one black spot by the exhaust port which rubbed off with my finger,

Cast Aluminum is funny it expands right before at seizes at 1221°F, I still run the bike to this day with same kit though I changed the piston and ring 3,800 miles ago!

Re: Seizing, but no damage?

jonah loshnowsky /

I wouldn’t say lean, so I guess it got too hot. How could I keep this thing cool?

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Re: Seizing, but no damage?

Brandon Weiss (Detective brandon to you) /

What does the cylinder look like?

Re: Seizing, but no damage?

b8es plug n retard timing

Re: Seizing, but no damage?

jonah loshnowsky /

The cylinder has a mirror shine, just like it did before I put the head on and soft seized it. I didn’t see any damage

Re: Seizing, but no damage?

Probably Fred /

> jonah loshnowsky Wrote:

> -------------------------------------------------------

> The cylinder has a mirror shine, just like it did before I put the head

> on and soft seized it. I didn’t see any damage

Remove cylinder Check piston and ring especially at bottom

Re: Seizing, but no damage?

> Ken Roff Wrote:

> -------------------------------------------------------

> > jonah loshnowsky Wrote:

>

> > -------------------------------------------------------

>

> > The cylinder has a mirror shine, just like it did before I put the

> head

>

> > on and soft seized it. I didn’t see any damage

>

> Remove cylinder Check piston and ring especially at bottom

^^^^^^^ this.

Re: Seizing, but no damage?

jonah loshnowsky /

Ok, I’ll check out the bottom of the cylinder and piston. I read something about air leaks causing an engine to run lean, with the new head I installed, could I have caused a gasket leak? if so would that be my problem?

Re: Seizing, but no damage?

There's a lot to learn about timing and spark plugs.

Re: Seizing, but no damage?

> Brandon Weiss (Detective brandon to you) Wrote:

> -------------------------------------------------------

> What does the cylinder look like?

yea!

you take a photo of your voltage reg but not your cylinder & piston? come on show us the smear!

Re: Seizing, but no damage?

> Rocco Taco Wrote:

> -------------------------------------------------------

> > Brandon Weiss (Detective brandon to you) Wrote:

>

> > -------------------------------------------------------

>

> > What does the cylinder look like?

>

> yea!

>

> you take a photo of your voltage reg but not your cylinder & piston?

> come on show us the smear!

LOL, I know right?....

Re: Seizing, but no damage?

jonah loshnowsky /

This is the worst of it, I didn’t want to go through and do take of the whole cylinder, because I’ll order a new top end some day in the future (this one still runs fine) for the sake of speed.

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Re: Seizing, but no damage?

You should probably take the top end off and clean the aluminum off the cylinder and have a look at the piston, esp the ring lands.

Re: Seizing, but no damage?

Probably Fred /

Yeah you probably got ring/piston damage,

The more you run not cleaned up it the more aluminum or lining is going to go onto your crankcase,

The moment you seize you should never run it until you clean it up try fixing the kit with a new piston or a new ring, or get a new kit because all you need is a flake or a piece of a ring to go into your crank/crank bearings and then your engine needs a rebuild

Re: Seizing, but no damage?

jonah loshnowsky /

Ok, well I guess now it the time to get a new cylinder. I am going to stay 50cc for legal reasons. How’s the 2fastmoto kit, it’s fairly inexpensive?

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Re: Seizing, but no damage?

Dirty30 Dillon /

Ewwwww, don't buy that. Look at those whack transfers

Re: Seizing, but no damage?

Probably Fred /

Re: Seizing, but no damage?

Your stock cylinder is cast iron and is probably fine, take it apart, clean it up and put it back together with new gaskets. You might have some scoring on the piston.

Re: Seizing, but no damage?

Dan (high idle) Conway /

B8es NGK plug makes a world of a different if you have a resistor boot and shielded cable, no electrode arm so the plug takes up less space in the chamber. Call me a bullsh*tter I dont care, I changed over from a b6hs on my stock a35 and the temps at wide open throttle ripping up mountains was a full 70-80 degrees less than i would have been with another plug. Keep in mind Im running a parmakit cdi set at full advance with Sha 15;15 and the dreaded biturdo (soon to be an estoril)

Re: Seizing, but no damage?

> Dan (high idle) Conway Wrote:

> -------------------------------------------------------

> B8es NGK plug makes a world of a different if you have a resistor boot

> and shielded cable, no electrode arm so the plug takes up less space in

> the chamber. Call me a bullsh*tter I dont care, I changed over from a

> b6hs on my stock a35 and the temps at wide open throttle ripping up

> mountains was a full 70-80 degrees less than i would have been with

> another plug. Keep in mind Im running a parmakit cdi set at full advance

> with Sha 15;15 and the dreaded biturdo (soon to be an estoril)

2 heat ranges should make 'about' that difference .

Re: Seizing, but no damage?

jonah loshnowsky /

Whoops I lost connection right after I posted the next message, and it posted twice. I just edited this one out because you can’t delete them. (edited)

Re: Seizing, but no damage?

jonah loshnowsky /

You guys were right about the piston, it’s pretty rough, and the bottom ring was stuck. Should I replace just the rings and piston? (Or would I have to buy a cylinder and piston together?)

-also

What do you mean by clean up the cylinder? Hone it? There wasn’t anything worse than what I showed earlier on it.

I’m looking for the cheapest way out, I’ve got plenty of money right now, I’d just rather not spend it.

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Re: Seizing, but no damage?

> jonah loshnowsky Wrote:

> -------------------------------------------------------

> You guys were right about the piston, it’s pretty rough, and the bottom

> ring was stuck. Should I replace just the rings and piston? (Or would I

> have to buy a cylinder and piston together?)

>

> -also

>

> What do you mean by clean up the cylinder? Hone it? There wasn’t

> anything worse than what I showed earlier on it.

>

> I’m looking for the cheapest way out, I’ve got plenty of money right

> now, I’d just rather not spend it.

Light home the cylinder and get a new piston/ring kit. Oh and top eng gasket set also.

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