There is always so much knowledge in this forum. We got a CR125r gifted to the family for some flat track training. Bike was not running and would not start. It was stored outside in the AZ climate for way to long. What I’ve done. Drained and refreshed gas. Went through and replaced electrical (plug / wire / CDI) Cleaned carb and flipped Reed valve. Bike starts correctly but something is odd sounding. Or am I being paranoid?
Nope, you're not being paranoid, there is definitely something there that doesn't sound right. I'd pop the cylinder off to get a look at the wrist pin and big end bearings and the general condition of the piston and bore.
Yes, been studying YouTube vids. Kids and I will do the top end tear down this evening. Wish us luck. I just hope it isn't in the crank. Splitting the case not something I want to do.
Yes, I have a new reed valve system, air filter, gasket kit, and petcock incoming via Amazon. This Saturday will be visiting AutoZone to replace all the fuel and cooling hoses.
This. What @Toadmeister00 wrote. Splitting the case isn't hard. Just need the right tools and patience. You'll wish you had while you have it open that far. Will suck to have a bottom-end mechanical down the road. p.s., flush the transmission and the coolant (remember to 'burp' it).
We opened up the top last night and found this. The guys from the CR Facebook group have been phenomenal. Appears the crank is about to let go. Kids and I have a winter project to completely rebuild a engine. A bottom end kit is on order. My only butthurt are the purchasing of special tools I most likely won't use again.
Case splitter, flywheel puller, and I use a tusk crank puller/installer. Works great if you don't have a press which I don't. Tusk tool was like 70 from rocky mountain atv. Flywheel puller 10-30 from same place. I have a motion pro case splitter I bought years ago so I don't know how much now. You can do all at the house with those 3 tools and not have a problem.
Yup, what @CBR723 said above is spot on. I have the Tusk case splitter and crank puller ($70 each from RMATV) and various Tusk/ Motion Pro flywheel pullers. You'll spend less on the tools than what you'd pay someone to rebuilt the thing for you. What bottom end kit are you going with? I would suggest that you NEVER run a Wiseco crank. Hot Rods stuff is a little bit better, but O.E. is the only way to go, in my opinion.
Well crap, a Wiseco kit pulled up on Amazon. Haven't pulled the trigger yet. And yes, we do all of our own work. Wouldn't be able to finance this addiction if I paid people to wrench for us. Plus the kids learn a great skill set in case college is not for them.
What year is that? I remember OEM honda cranks on pre 97 bikes were cheap compared to other brands. You can also just do the rod but will need a press and true it up. I think at time my cost was 100 for assembled crank. May not be in stock anymore. Wrench rabbit kit has been good.
1998, I'll dig into it further. Partzilla Crank only $262.89 Wrench Rabbit Complete kit $454.28 Amazon Wiseco Complete kit $234.85 This is a flat track build not a MX purpose. What exactly is the knock on the Wiseco?
Rocky Mountain is 220. Pro x also has crank assemblies and rods if you want to do extra labor. I think the wiseco problem was rod fatigue and breaking in half then killing the cases.
Honda East Toledo has the cranks for $205. For that price, it's not worth rebuilding your existing crank. When you add up the new rod kit, labor and shipping back and forth to whoever would do the work, you'll be at roughly the same money. If you were working on a KTM or Husky where the cranks are $400-600, rebuilding them makes perfect sense. Regarding the Wiseco cranks, there are just so many failures with them that it's not worth the risk (big end bearing failures). Spend a few minutes searching around the various 2T forums on Thumpertalk and you'll see for yourself. My personal experience with them is a friend's 150R that had the rod break on a Wiseco crank with very little time on it. It wasn't pretty, the cases were completely wrecked. It's just hard to go wrong with the o.e. cranks and the quality o.e. Japanese bearings. Same with the pistons, the o.e. are made by Art and are good. I do like and use the Tusk gasket and seals kits. O.E. would be my first choice with either an o.e. or Vertex piston, the Wrench Rabbit kit (Hot Rods crank/ bearings) would be my second choice. Those seem to be hit or miss. Lots of people getting 100+ hours with them, and some random low-hour failures.
If you are doing crank do all your bearings as well, you are already there. Most of the bearings will come out easy if you heat your cases in an oven @275 deg. and tap them flat on piece of wood. Clutch engagement pin bearings you will have to use blind bearing puller which can be handy if you have stubborn case bearing. Use GOOD bearings NTN, KOYO…
Glad to see you are able to work out the motor issues. We talked about it at GNF. I'm the vintage guy that was pitted just down from you and your kids. Special kudos to you for keeping several kids on bikes at the track!
Well thank you so much! Parker still talks about you Mustang pulling your enclosed trailer. Guys like us are whom keeps this sport going!
Whelp, this little test of patience monster has finally been defeated! Complete rebuild with extra $$$ spent on the cylinder. We learned a bunch but I just don't think 2 smokes are for us. Anyone know what it is worth?
