Engine rebuild

[Lit Hawk]

So my piston blew up my engine again luckily it was stilll under warranty and txpowersports sent me new pieces to try and rebuild. They sent me a new piston, cylinder, jug, crankshaft and gaskets. So now I need to remove all busted pieces from case. My question is what is the best way to remove all metal from case. Should I use a tub of diesel fuel to rinse everything out. Any help and tips on doing this really appreciated guys. Thanks

[Lit Hawk]

Pics of the damage

[Lit Hawk]

More pics

[Sochin]

They should send you a whole new engine.

[tomrom]

Originally Posted by Sochin

They should send you a whole new engine.

If your engine is under warranty your vendor should be able to stick up for you.

When this happened to me last summer Don from apscusa.com insisted his supplier, Goldenvale inc issue a new engine. I was involved in the process and spoke direct to the decision maker at Goldenvale Inc. with some testimony. It was thought there was a vacuum leak.

I don't think it was an easy process for him but Don stood up for me and got me the engine. It took about 3 months which is a crazy long time.The bike has tons more power now also.

[Megadan]

Originally Posted by tomrom

When this happened to me last summer

Holy moly! That is some serious meltdown!

[JerryHawk250]

Originally Posted by tomrom

If your engine is under warranty your vendor should be able to stick up for you.

When this happened to me last summer Don from apscusa.com insisted his supplier, Goldenvale inc issue a new engine. I was involved in the process and spoke direct to the decision maker at Goldenvale Inc. with some testimony. It was thought there was a vacuum leak.

I don't think it was an easy process for him but Don stood up for me and got me the engine. It took about 3 months which is a crazy long time.The bike has tons more power now also.

Don is one of the few dealers out there that will help out a customer. I would and probably will buy from him again. First class guy

[Tashka]

yeah, putting all that work on you. How the heck does it blow up twice. There must have been an issue there that wasnt fixed with the replacement. Maybe something with timing?

What were you doing to break it this time and last time? how much actual engine run time did you get? because these engines can generally take quite a beating. My hawk has 11.5 compression and I like to run it hard.

[Megadan]

At this point I would have them send me new bearings for everything as well. Those metal fragments get in everything.

As far as cleaning it. Diesel or kerosene works. A parts washing detergent works. It really just depends on what you are after.

[Lit Hawk]

Originally Posted by Megadan

At this point I would have them send me new bearings for everything as well. Those metal fragments get in everything.

As far as cleaning it. Diesel or kerosene works. A parts washing detergent works. It really just depends on what you are after.

So I guess they’re not sending me the bearings I requested or the bottom engine gaskets. Does anyone know where I can get bottom engine gastkets. And also if I can buy the bearings from a bearing distributer or do I need to get specific dirtbike bearings. Do you think the engine would be ok with not replacing bearings?

[Megadan]

Originally Posted by Lit Hawk

So I guess they’re not sending me the bearings I requested or the bottom engine gaskets. Does anyone know where I can get bottom engine gastkets. And also if I can buy the bearings from a bearing distributer or do I need to get specific dirtbike bearings. Do you think the engine would be ok with not replacing bearings?

I wouldn't personally re-use the bearings if I didn't have to as there is no way to ensure you get every fragment out that may be trapped. There is also always the risk of damaging the race when removing a bearing if you find yourself having to do so. The crank should come with new ones, but as far as the others go, you can easily source new bearings by using the bearing codes on the bearings themselves. Just make sure to match the style (seals, no seals, one side seal, etc). Any bearing distributor can easily help you match up what you need, and doing it this way you can also ensure that you get really good quality bearings.

As far as case gaskets, you can get whole kits off of ebay. Here is one from a US Distributor. https://www.ebay.com/itm/67mm-250cc-...4383.l4275.c10

I would look into having new shifter shaft and kick start seals as well, and don't forget the exhaust gasket. They might be fine now, but the lips can get damaged when removing or re-installing, so it never hurts to be prepared. Lastly, as I am sure you are well away but I want to state it anyway for posterity, make sure to clean the crap out of those cases.

[Lit Hawk]

Awesome as always! Thanks megadan, just the info I was looking for! I wanna throw this engine together as soon as possible but wanna do it the right way the first time. I guess next step is removing bearings and seals and replacing. Also thanks for the link for gasket I searched and really couldn’t come up with anything that I knew was a for sure fit. I’ll probably pull all bearings and seals out in the next couple of days and post them for reference but don’t seem like y’all need them like I do. Thanks againe

[NzBrakelathes]

They should send a new engine n get this bucket of bolts back
That’s crap service for such major failure

[Lit Hawk]

Yeah I agree I should have got a new engine. But I didn’t want to push it. Engine has about 8000 miles on it. I’ve had it for about 9 months and ride it to work every day most of that on freeway. First thing they said was I must not have broke in correctly or kept up with maintenance. This being the second engine I’ve made sure to keep up with it usually oil change every weekend and I did proper break in. This time I was going about 65 on freeway and it just died sounded like my exhaust was dragging but nope. I’m gonna try to get it running today or tomorrow and just rinse everything out with diesel real good. I’ll let y’all know how it goes

[Kivi]

Originally Posted by Lit Hawk

Yeah I agree I should have got a new engine. But I didn’t want to push it. Engine has about 8000 miles on it. I’ve had it for about 9 months and ride it to work every day most of that on freeway. First thing they said was I must not have broke in correctly or kept up with maintenance. This being the second engine I’ve made sure to keep up with it usually oil change every weekend and I did proper break in. This time I was going about 65 on freeway and it just died sounded like my exhaust was dragging but nope. I’m gonna try to get it running today or tomorrow and just rinse everything out with diesel real good. I’ll let y’all know how it goes

65mph = 110kmh on this pushrod engine on highway seems too much. I read somewhere that on this engines max speed for prolonged length of time is 80kmh. My bike fits into this frame - comfortable speed for the engine is about 60kmh, on 80kmh there are more noices, but kind of acceptable, and 100-110kmh I have driven it only for a few seconds, because I have bad feeling that the engine does not like it and it could blow.

About the engine washing, when I had gearbox problems, 2 years ago, when i split the case in half, I preassure washed it (everything was removed from the cases - just aluminium left), putting attention to the oil passages which go through engine block. I first degreased them, then pressure washed.