Ran over to Scrappy's and picked up a new crankshaft, piston rings, and gasket set. Taking a break from cleaning her up now, and I have the new crankshaft in the freezer. Sun is going down and I have horrible light in the garage, so I'll probably button her up tomorrow morning. Can't wait to get my baby back on the road!
I have yet to get more than 15k (prob 10k on average) on a 139qmb 50/72cc crankshaft. The crank rebuilds I did lasted even less than the originals.
I debated for awhile on getting a beefier, better quality crank but those run $120-170. So between the higher crank prices, new top end, all the other smaller things, I said screw it and bought a new engine instead the last few times.
Just shy of 10,000 miles. This being the 16" wheel engine, I'm limited to stock crankshafts, AFAIK.
Post by JerryScript on Nov 30, 2016 17:15:42 GMT -5
Well when it rains in pours! First my younger nephew's Icebear had a con-rod bearing fail, had to split the case and replace the crankshaft. Next my older nephew's Rocketa had the stator pulse coil burnout, bent the flywheel removing it, had to replace both. Now my SSR just had a crankshaft failure. Let's hope it only comes in threes!
My 150cc SSR Phoenix stopped working a few days ago, and I started to pull her apart this morning. Got the plastics off and nothing visible wrong. Pulled the plug and cranked her over and had good spark, but she barely could turn over. Pulled the valve cover, and laying right there was this piece:
For those who are wondering what piece of metal inside the engine has rivets and is shaped like that, it's the bearing retainer for one of the two main crankshaft bearings. Here's a pic of my nephew's old crankshaft showing it:
So I'm splitting my second case in two weeks. Got lucky with both the flywheel and the kickstarter gear. Was able to pull both off with a standard claw puller. Here's a pic of the kickstarter gear removal:
Note- I used this same puller to pull the flywheel on my Nephew's Icebear and my SSR with no problems. However, on my other nephew's Rocketa, it bent the flywheel reverse mushroom style, so it had to be replaced. Use this method with the understanding you may have to replace the flywheel in the end, probably better to get a working flywheel puller (the one I purchased had bad threads).
Will post some more pics later of the rebuild. Not looking forward to removing the motor mount on this beast!
Post by JerryScript on Nov 29, 2016 2:03:32 GMT -5
I hope it comes thru soon. You will definitely enjoy your new ride, I know I have! (I have the same one)
Use this as a last resort: most cities, counties, and the states have websites where you can find the details of the company and/or it's owners. Google the name of the city/county/state with the term "business entity search". Almost every Secretary of State has a search feature listing officers of all forms of corporations. Once you have names, you can find phone numbers.
Got the woodruff key, slapped her back together, started up after about 30 seconds of priming. Took her for a spin around the block, no problems other than a little bit of adjustments needed (carb, rear brake, ect).
For the most part, the entire job of splitting the case hasn't been too difficult. For reassembly, I kept the crankshaft in the feezer overnite, and used a torch on the case, pushed the cam chain in so it was out of the way, and the crankshaft slipped right in. I hit the other side of the case with the torch, and it slid right onto the other end of the crankshaft no problem at all.
NOTE - Remember to keep your bolts labeled in some way so you remember which length goes where and you shouldn't have any trouble with a lower end re-build like this. I couldn't get the woodruf key out of the old crankshaft, so I've gotta run over to Scrappy's tomorrow and pick one up, then slap the rest back together and fire her up.
Post by JerryScript on Nov 14, 2016 15:10:37 GMT -5
My nephew's Icebear suddenly stopped working last week. It made a bad noise from the crankcase, and would only start with lots of throttle and would not keep running.
I tore the top end down first, no issue with the head, jug, or piston, so I had to split the case. As soon as I it apart, I grabbed some oil from the inside on my fingers, and it was silver. I cleaned out at least a 1/4 teaspoon of very fine metal. Pulled the crankshaft, and the outer bearings were fine, though one did have a slight bit of drag. Grabbed the con-rod and found at least 1/8" play up and down. No damage to the rest of the internal parts of the engine, no wear or scrapes of any type. Looks like the con-rod bearing failed, so I'll be heading to Scrappy's tomorrow for a new crankshaft.
This Icebear has a 47mm BBK, which is generally not a big enough upgrade to cause crankshaft failure. My nephew does ride 2-up alot, giving friends rides everywhere, so it could have been stress, but I'm leaning towards a manufacturing flaw that finally failed after a year.
For those curious, it's ok to have a tiny bit of play side to side on the connecting rod, but up and down play is very bad. It can cause the piston to hit the head, and will make it appear as if you've lost compression, since the chamber area is larger with the con-rod able to move further back. Over time, it can shatter the skirt, or end up with catastrophic crankshaft failure, worst case blowing the engine.
Post by JerryScript on Nov 10, 2016 0:29:04 GMT -5
I may have to deal with this on my nephew's scooter. I'll call the DMV and see what I can find out. In Nevada, vehicles can be registered without being titled. The standard procedure is to have a bill of sale and the MCO, but a quick google search shows it can be done without either under certain situations. I'll let everyone know what I find out.
Post by JerryScript on Nov 10, 2016 0:16:43 GMT -5
One thing many people don't take into consideration is the cleanliness of the engine. These air cooled engines rely on the air being able to touch the metal and transfer the heat away. A build up of road grime will cause an engine to run hotter, leading to issues sooner. Clean that baby regularly, change the oil regularly, and DO NOT REV THE ENGINE WHILE MOTIONLESS, and you will get far more miles than a dirty engine will.
The vast majority of people scrap an engine that could be easily fixed because they aren't mechanical, and the local scooter shops aren't exactly trustworthy. Many figure it's cheap enough to just buy a new scooter.