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About 1987CR250R

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    Dirt Biking of course

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  1. A machine shop would be able to weld and rethread the end but you would probably be looking at at least $400 for that and you still have to true the crank afterwards.
  2. 1987CR250R

    Top end break in method?

    I don't know where these stories come from. I work with heavy duty engines Cat EMD and John Deere. They all prefer to sell you cylinders with the piston already installed and they are all coated with an assembly lubricant. Not lubricating any moving part of any engine for any reason is a bunch of hooey.
  3. 1987CR250R

    Spoke thread lubricant.

    Silicone is not a good lubricant. It works great for protecting light bulb sockets from environmental exposure at high temperatures. It does not work well under the extreme contact pressures seen in threaded connections. An yes it may appear anti seize had hardened and deteriorated after its base oils have washed or evaporated away but the powdered metal lubricants will remain in place and are still funtional.
  4. I'm working on a 1980s Trail 110 with a keihin PB10 carburetor (not the original). Anyways it starts and idles fine but as soon as you touch the throttle it dies from fuel starvation. Float level is good. Jet is a stock 72. If I blow into the vent tube it floods the engine the everything runs fine for the moment while it clears out. Is it possible the pb 10 carburetor needs that much larger of a main jet than the original I believe pb 21
  5. Increasing oil pressure may have significant effects on the way the cam chain tensioner behaves but I do not believe that has ever been brought up on the internet so I know little about it
  6. The key about oil pressure in any modern engine is that it exists to provide a sufficient oil flow to parts of the engine to keep the parts cool while hydrodynamic forces actually work to keep the bearings lubricated. Look at your typical nascar engine It may have a six stage oil pump. It may have one highest pressure stage dedicated to spraying oil at the back of the piston for cooling reasons. The rest of the stages provide precisely calculates oil volumes to minimize parasitic losses. Some heavy duty engines use a higher pressure for the wrist pin because it has to survive a difficult oscillating motion but for the most part bearings don't benefit from higher oil pressures.
  7. If you want the bike to perform and last like the exc install the exc cam and do what you need to get exc compression ratio
  8. What do you expect to gain by increasing you oil pressure by only 8 psi.
  9. If you slit the bearing and it is still not loose then you have not cut the way through. Once slit the bearing will come out no matter how stuck.
  10. 1987CR250R

    Helicoil trouble.

    300 series stainless steels become magnetic as the are work hardened. The coiling of the wire into an insert is what makes them hard.
  11. Bolts need tension to compress gaskets and resist forces they must be tightened properly and using loctite to hold a loose bolt will cause failures.
  12. I cut most if my gaskets out of Garlock 3000. It has a coating that helps it release easily from flanges. But it's usually cheaper to buy the gaskets pre cut from the dealer. Also the thickness if the gasket may be critical for clearance but most motto gaskets are close enough to .015 inch or 1/64 inch.
  13. Generally you should have no interchangeability issues. With some of the newer sport bikes you must use an agm battery simply because of differences in power density. A conventional battery simply won't roll the engine over. There are no other risks. Generally an agm battery wants to see a higher charging voltage to get the best life but if you are seeing anything from 6.3 to 7.2 volts from you charging system any lead acid will be ok. An agm will take up to 7.4 volts. Ok but after looking at your pictured battery you do have to look at the draw rate as well as amp hours. All batteries have an internal resistance and this caps the peak current the battery can drive. This is very important if the battery is to be used for starting. Also if the plates in the battery are not thick enough a high current draw can cause rapid deterioration of the battery.
  14. Detroit diesel put a scavenging pump at the front of the oil pan on there dozer engines for operation at extreme incline angles. The pump simply pumped oil from the front of the pan to the back. But your engine isn't long and should no need such a setup. Perhaps you need to install a baffle on the breather to keep the oil from leaving the engine in the first place.
  15. I find greases prevent corrosion whether it be water based or fretting based than the moly pastes due. I prefer not to use conventional greases only synthetics for the longer relube interval and the difficulty nvolved in swing arm lubrication. I find the Mobil greases to be a good deal the Mobil one is about ten dollars for a pound at most automotive supplies. Mobility shc 100 or 220 would be suitable however I am interested in trying the mobility shc pm 460 due to better corrosion inhibitors.