Is it necessary to clean a new engine?

[outatime88]

So I bought an engine kit off eBay like many others have done, and read on one thread that somebody had some dirt/metal shavings in their crankcase of a new engine(not sure where they bought it) that they washed out with wd40 a couples times and then used oil. Now my question is it necessary for me to clean my engine before using it? What are the chances of it being just as dirty or would it even matter that much or be harmful? I don't really want to go through the hassle of opening everything up and really just want to build it already and start riding. Also I would think wd40 would be somewhat harmful becomes of the abrasives it has for cleaning.

 

[butre]

I've found little balls of aluminum in new engines before. stuff that would kill the engine in 5 minutes or less if I hadn't cleaned the motor first.

wd40 has no abrasives in it, whoever started that myth is a moron. it's mineral oil, solvents, and propellant.

 

[crassius]

I open and oil them - have found all kinds of crap over the years - had a few that had never had the ports machined out, some with thin flashings of metal just hanging by a thread waiting to kill the motor - once found an intake gasket that had never had the hole punched thru the center !!??!!

 

[outatime88]

I open and oil them - have found all kinds of crap over the years - had a few that had never had the ports machined out, some with thin flashings of metal just hanging by a thread waiting to kill the motor - once found an intake gasket that had never had the hole punched thru the center !!??!!

I've found little balls of aluminum in new engines before. stuff that would kill the engine in 5 minutes or less if I hadn't cleaned the motor first.

wd40 has no abrasives in it, whoever started that myth is a moron. it's mineral oil, solvents, and propellant.

Ok so I if I am going to to clean it out, do I need to start taking stuff apart like the clutch, or do i just need to take the crankcase cover off both sides and runs some oil through it to get the gunk out? How do you clean yours?

 

[KCvale]

What brand of engine did you buy?
If it's a Skyhawk you don't need to open it, they are quality engines and having built 68 of them I have never had to crack the case.
http://kcsbikes.com/KCsBuilds.asp?motor=2-stroke&shifter=All

The problem with 'cracking the case' is getting it back together right and not for the rookie that just wants to just 'make it go'' ASAP.

I suggest you just roll the dice and ride it.
If it fails just get yourself a Skyhawk engine.

 

[crassius]

inspecting is hard to explain - if you don't know what to look for, you may not see things right in front of you

I don't wash anything out with oil, just wipe a bit with paper towel if some debris is there in cylinder. If motor is together, I'd take off head and lift barrel just enough to oil base gaskets and using a dental injector about 6 drops of oil on lower end bearings and same up inside piston on wrist pin (without some kind of injector, you probably can't get in there - before putting head back on, I get oil on my finger and spread all around cylinder walls. On clutch side, just a peanut sized dab of grease between large & small bevel gear and turn motor to spread it evenly, then on drive side I take out bucking bar and pack grease in hole then force bar back in (oozing is OK as it will get nicely onto chain as it runs), then grease clutch arm shaft & pack that hole in cover with grease too.

too much typing - probably forgot a lot : (

 

[outatime88]

What brand of engine did you buy?
If it's a Skyhawk you don't need to open it, they are quality engines and having built 68 of them I have never had to crack the case.
http://kcsbikes.com/KCsBuilds.asp?motor=2-stroke&shifter=All

The problem with 'cracking the case' is getting it back together right and not for the rookie that just wants to just 'make it go'' ASAP.

I suggest you just roll the dice and ride it.
If it fails just get yourself a Skyhawk engine.

It says Seeutek on the side. Here's a link: http://m.ebay.com/itm/2-Stroke-80cc...3A67ff17d715e0aca47336140afff5cccf%7Ciid%3A11

I mean I've rebuilt a beat to **** 350 chevy. But never touched a 2 stroke engine before lol.

inspecting is hard to explain - if you don't know what to look for, you may not see things right in front of you

I don't wash anything out with oil, just wipe a bit with paper towel if some debris is there in cylinder. If motor is together, I'd take off head and lift barrel just enough to oil base gaskets and using a dental injector about 6 drops of oil on lower end bearings and same up inside piston on wrist pin (without some kind of injector, you probably can't get in there - before putting head back on, I get oil on my finger and spread all around cylinder walls. On clutch side, just a peanut sized dab of grease between large & small bevel gear and turn motor to spread it evenly, then on drive side I take out bucking bar and pack grease in hole then force bar back in (oozing is OK as it will get nicely onto chain as it runs), then grease clutch arm shaft & pack that hole in cover with grease too.

too much typing - probably forgot a lot : (

Thanks for the details of what you do. I want to take a peak inside but I don't have a torque wrench for the head when I'm done. Maybe I'll just try and take the cover off and go on from there.

 

[Frankenstein]

It says Seeutek on the side. Here's a link: http://m.ebay.com/itm/2-Stroke-80cc-MOTOR-ENGINE-KIT-GAS-FOR-MOTORIZED-BICYCLE-CYCLE-BIKE-SPEEDOMETER-/172176035987?epid=689890589&hash=item28167dd093:gQAAOSwa51ZbIqg&_trkparms=pageci%3A701d3192-9590-11e7-9dd4-74dbd1809abe%7Cparentrq%3A67ff17d715e0aca47336140afff5cccf%7Ciid%3A11

I mean I've rebuilt a beat to **** 350 chevy. But never touched a 2 stroke engine before lol.



Thanks for the details of what you do. I want to take a peak inside but I don't have a torque wrench for the head when I'm done. Maybe I'll just try and take the cover off and go on from there.

Autozone has a tool rental service, give them money and they give you tool, bring tool back in and they give you all the money back. You could tear it down when you have time look around, put it together with headbolts finger snug and ride the the bike to autozone, rent it for 30 seconds and come back in.

You can get a torque wrench for under 15 bucks at places like harbor freight and if you want anything to do with this hobby you'll want to have it when you need it, you have to check the head bolts anyway a few times as things loosen up during the first few rides.

They happen to be a great tool for many other applications anyway, so get it and use it.

On another note you still should torque the head down proper before the first ride since they don't generally do that for you, and on a final note you can't use the same silver head gasket more than once, if it's been printed in by the head and cylinder it's basically spent since you can't get it to match back up to the same imperfections. Highly recommend a copper gasket (not that copper coated bulls**t you see now too on ebay) which can be annealed with a torch and water and made to be usable again multiple times. I myself had 3 gaskets that I've used over and over again and one or 2 of those moved onto other motors and still in service after a couple years now. Good investment.

 

[6blueoval9]

A clean motor is a happy motor.

 

[KCvale]

I want to take a peak inside but I don't have a torque wrench for the head when I'm done.

Harbor Freight is having a Labor Day sale...
Get yourself a torque wrench bud.

I usually remove the head to paint it and rotate it 180° so the plug points forward so I do this all the time.

I torque my heads in an X pattern 5# at time to 20#, that is more than spec but hey 68 2-stroke builds and no head gasket issues so I stick with what works.