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Discussion Starter · #1 ·
Good morning!! New user here with a question...

So my wife's uncle passed 9 years ago and his 1992 TRX200 Type II sat in the garage in pieces since then. I decide I really don't like myself and will try to get the thing running again. A week of scrounging in the totally disorganized garage and I scrounge enough parts to re-assemble the engine. In doing so I find the one-way starter clutch is FUBAR. A quick trip to eBbay and I locate one for about half a C-note still attached to the flywheel. SCORE!

Get the part and assemble the engine. Surprisingly it starts on second shot of starter fluid; however, the carb vent are, well,, venting a lot. In the excitement of my mechanical prowess I shut the petcock off and throw the chain on the sprocket because I'm going to show off and drive it around until the bowl runs dry.

Roll it out, start it up, put it in gear... stall. Try to re-start and the starter spins. Uh-oh....forgot to torque the flywheel bolt. Fearing I sheared the key I tear the left side down and thankfully find the key doesn't appear to be sheared off. I disassemble the carb fix the stuck float and put it back together. Reassemble the beast and fire it up.... nothing - zip - nada. No amount of started fluid or gas will get it running.

When I go t o check the timing marks (there was some back pressure coming out of the carb the day before) I find that when the "T" is aligned to the index mark the cam indicator is nowhere to be seen. Rotating the flywheel about 180 degrees the cam indicator is seen and the piston is now at TDC. I'm not an expert, but after reading this forum I'm pretty sure I messed something up... the question is what and how bad?

Any ideas to point me in the right direction?
 

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Hard to determine without seeing it, but my first guess is that the cam chain tensioner has failed allowing the cam chain to jump the teeth on the sprocket and now you may have a bent intake valve.

When you installed the cam chain tensioner, did you retract the plunger as you installed it and then after installation, back it off slightly and release letting the spring set the tension?

The only other thing I can think of is a wrong cam chain. 102 pins vs the required 100 (I have seen it done in several different engines usually by someone who thinks the length is not important or it's supposed to be a high performance option - it's not - it has to be right)
 

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Discussion Starter · #6 ·
Issue solved - Took top end apart... nothing wrong there... put it back together and for giggles tore the left side down and pulled the flywheel... woodruff key IS sheared... now waiting for the long weekend to be over to go buy a $2.50 part.

Thanks for the advice... I learned a lot about tearing an engine down this weekend... with luck I'll be up and running again Tuesday evening....
 

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When you install the flywheel, keep in mind it is not the key that retains the flywheel - the key only lines the flywheel up so it is in time - it is the taper that retains the flywheel, you just have to get it torqued properly. The trick is holding the crankshaft so you can use a torque wrench.

One way is to get the piston to about 3/4ths of the way to TDC of the compression stroke and fill the cylinder with liquid (I have used diesel fuel and kerosene) - put the spark plug back in, torque the flywheel, then remove the spark plug, put a bunch of shop towels (or similar) over the spark plug hole, make sure the ignition is dead and crank the motor over to get the liquid out of the cylinder. Turning the crankshaft by hand will push out most of the liquid and wrapping a belt or rope around the flywheel to pull and spin fast will get about 95% of the liquid out. Then let air out for a day or two and try starting normally. If you are adventurous, experienced or stupid, you can use gas, lacquer thinner or alcohol for the liquid. All mentioned are flammable and you should have a fire extinguisher nearby in case of an emergency

I have done so many that I just use an air impact tool (I have used an electric impact successfully) to tighten the flywheel sufficiently without actually using a torque wrench.
 

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Discussion Starter · #8 ·
I have read where some use lapping compound between the taper and flywheel to hone the mating surfaces before installation... any thoughts?

Good idea on the fluid in the cylinder :)

I have plenty of diesel on hand...
 

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OK - I'm an azz-hole, but I accept it. :rolleyes:

I have lapped many valves and even cylinder heads. Valves of the lapping variety (you don't lap certain ((like Titanium)) and/or specially coated valves) are very hard, but the lapping is done on a very small area and most of the lapping process occurs to the valve seat. Cylinder heads are soft, usually aluminum or cast iron. It takes just a few minutes on valves and, depending on the size and how true the head was milled, it takes about from 5 to 20 minutes to lap one. The crankshaft is hard steel and the hub of the flywheel is even harder steel. Lapping compound (available in different grits, mediums and types of material) is for removing very small amounts of material. The machining of the crankshaft and the flywheel hub are precise, but (in my opinion) can only be minutely improved by lapping. It is an unnecessary procedure. Proper torquing is all that is required.
 
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