looking for engine rebuild

[frankr2994]

since it is a 2 stroke its very easy to crank a few more hp while you have it apart. take your head to a machine shop and take about .010" off of it. and if you have a dremel tool clean up all your ports. not saying you should try to do a full port and polish that requires laying out all the ports and using a degree wheel but just clean them up. take out all the rough edges. any thing that looks like it could restrict you can grind down. the intake side needs to have a slight roughness to it but the exhaust port you can make look like a mirror if you'd like.

but all in all 2 strokes are very simple. pay attention to how everything comes apart and lable all your bolts and hardware in baggies. the bottom end if anything like my dirtbike and atv crankcases i have done you will have to press both sides of the case onto the crankshaft. if you do not have a press then you will have to take it to someone that knows what they are doing with it.

[Dave Box]

Originally Posted by golfdad

Hey guys how do you get the cluch off? and does the bolck come apart to take out the cranck?

Hello again Golfdad,

To get the clutch off you need to either purchase or make a tool. If you decide to make it you will need a hardened steel bolt 3/4 inch fine thread and 2 inches long. You will also need a 7/8 steel rod 3 inches long.

You need to remove the long screw in the center of the clutch and then I recommend that you spray the crankshaft around the clutch with a good release agent like Liquid Wrench and let it soak overnight. Now insert the rod into the clutch and wind in the bolt. As you drive in the bolt the cluch will slide off the shaft. Well that's the theory. In practice the engine will try to turn as you tighten the bolt. For me this was not an issue as the engine was seized solid but even then it required some grunt. There are two further options one is to use an impact wrench the other is to get the cylinder off and put some wooden blocks under the piston to stop it moving as you lean on the wrench.

The second part of your question yes you will need to remove the head and the cylinder which is held onto the crankcase with four bolts. Now you can split the crankcase and remove the crankshaft. From your first post I am guessing that the bearings are shot so it should all fall apart. If not a little tickle from a heat source should do it.
Dave

[frankr2994]

Originally Posted by Dave Box

The second part of your question yes you will need to remove the head and the cylinder which is held onto the crankcase with four bolts. Now you can split the crankcase and remove the crankshaft. From your first post I am guessing that the bearings are shot so it should all fall apart. If not a little tickle from a heat source should do it.
Dave

yes and when installing new bearings it helps to have the cases hot and the bearings kept in a freezer. be careful when heating the cases though. safest way is with a hot plate but you can use an oven and if your real careful you can use a propane torch. if you get it to hot there is a chance it can warp.

[bananaman]

Originally Posted by golfdad

Hey guys how do you get the cluch off? and does the bolck come apart to take out the cranck?

I have the bolt/puller I bought from BU if you need to borrow it, but you may be too far from me.I am in Durham,NC

[golfdad]

Thank all I got it off

[golfdad]

GetAttachment[1].jpg can you please help me get the fan off thank you

[Dave Box]

No problem Golfdad. It goes without saying to first remove the nut in the center. On the fan you will see two flat blade dome headed screws. All these do is protect the threads that you need to use to pull the fan. So pull those out and now you use a steering wheel puller to pull the flywheel off. You will probably need to buy some bolts to fit and I believe that they are 8 mm, but I could be wrong. Also are you changing the crankshaft? I think that you said you were, if so you don't care about tearing up the end with the puller. If you are keeping the crankshaft then you should protect the slotted end with a 1/2 inch socket that will slip over the end.
If the flywheel has been on for years it will be tough to remove, but it does come off. Just keep winding on the puller. Do not be tempted to put a lever behind the flywheel to help prise it out. The aluminum casing is fragile and you will break the lip.
You're doing a great job, keep us posted.
Dave

[BrewCityMusic]

sometimes it also helps to tap (!) on the flywheel with a hammer while you have the puller under tension - I used a small piece of steel as a drift when I did it, to keep from damaging the flywheel while raining blows on it with the hammer ... Like Dave said, these can be a real b__ch to remove if they've been on for awhile, but stay at it and eventually you'll get it to pop loose

[golfdad]

Thanks again for all the help I got it off but it was a b**** and now i cant seem to get the bearing out of the block. Thanks

[Dave Box]

I assume that you have the cylinder off and all the bolts out of the two halves of the crankcase.

The bearings can be in there tight but from your earlier description the rear bearings were probably just flopping around (you said that you had vertical play on the crankshaft). If this is the case I would expect the rear crakcase half to pretty much fall off. When I did mine I struggled to get the front crankcase half off the shaft until I tickled it with a blowtorch. I used one of those things that you get from Lowes with the yellow cylinder of gas. Anyway a gentle application of heat and the bearing just fell out. Under no circumstances should you be tempted to try to prise the crancase apart with a pry bar. It is essential to the running of the engine that the crankcase halves are absolutely air tight when you rebuild the engine.

Did you get a bottom end rebuild kit? If so you will need to get the new bearings onto the new crankshaft. I tried all the tricks of putting the crankshaft in the freezer and so on and my experience was that it was a huge waste of my time. I took the whole shooting match to a small engine works and they pressed the bearings on for a donation to their pet charity.

Keep us posted
Dave