An uninteresting 200x thread

[Dirtcrasher]

Just checking your bottom end oil level before a ride is really important to these overhead cam units. Dennis Kirk has a timing chain guide set with the chain for a good price and it is good stuff. My 200X has been abused (once warmed up) but doesn't make that crappy sound most 1st gen 200X motors often make.........

You can always go back to a nice auto X motor; I wonder if Benny has those or just 185's. All take out motors about 600$, he got em and they are well worth the cost IMHO.

Wiseco makes a very good piston. I was able to toss a 10.25:1 into a 350X crate motor with a perfect clearance; I was surprised but very happy.

Since where talking about "Wiseco". How many of you call the Wissco or Wise-co, kinda like Teck-ate or teck-atty

OMG, he mentioned oil…can I PLEEEEASE talk about oil now, huh can I?

Yes, we can talk about the portions of the motor that removes (or tries to) remove contaminants.

[barnett468]

Yes, we can talk about the portions of the motor that removes (or tries to) remove contaminants.

Dang it, this is all I got.

Post 26.

METAL IN OIL - As far as metal bits in the engine go. I like to use magnetic drain plugs. Tri Again likes to stick Neodymium magnets on the drain bolts instead. The magnets keep most of the steel [from gears wearing etc] out of the oil.

[Dirtcrasher]

Yeah the 1st gens have that giant 24 or so mm that holds the crappy big parts in a mesh filter - you know...

[lokisbuddy]

Since where talking about "Wiseco". How many of you call the Wissco or Wise-co, kinda like Teck-ate or teck-atty

I say Wise-co and while I no longer have it I called my 86 tec-otty F***in C u next tue lol

[redsox]

some cleaning today, and some measuring. snow and work have a way of getting in the way of fun. so, i concentrated on getting the mating surfaces clean on the good jug. scotch pad and carb cleaner. there are no deep scratches or gouges. i feel good about it.



you can see the broken fin in the last photo. not the end of the world.

i measured the cylinder, then the piston on top, canter, and bottom. it's all pretty close. all the measurements are within 3 hundredths. i'm thinking more and more that i'll reuse the piston. there doesn't seem to be much wear. i'm cleaning the jug now and i'll hone and clean again tomorrow. i'll lap the valves over the weekend while i wait for parts and i'll be ready for reassembly next week.

[DohcBikes]

3 hundredths? You should be working with thousandths, even in mm, to get an accurate picture of what the cylinder "looks"like. Maybe post some actual measurements for us...I have every stock spec and clearance right here handy.

[redsox]

One crucial step which may have been mentioned, is to completely clean all cylinders bored or honed in warm soapy water to remove any hidden traces of fine metal after a hone,bore or contamination. Dry it fast and some light oil will prevent the "flash rust".


I also like to chase all threads with a tap, making sure 1.5X the diameter is the length needed for optimum thread strength. For example, those 6x1.0 pitch case bolts need to be 9mm thread length, more is not necessary. I learned this when working with a toolmaker as well as owning my own machine shop.


Check ALL gasket or honda-bond mating surfaces with a fine stone such as a toolmakers stone with WD40 and watch the high spots disappear!! Remove the dowel pins and clean them, then lightly oil them and reinstall them for an easy re-assembly. These issues you may find are from prior owners that smashed mating surfaces apart, and back together. Most motors have a casting "boss" for a brass drift and light to avoid damage to the surfaces.


I also apply grease to my clutch cover, stator side cover gaskets and some others and don't have leaks; The gasket can be re-used.

It's also time to yank the clutch cover and clean the "oil filter rotor" which is a centrifugal type of oil filter rather than a paper oil filter element such as on your 86/87 250SX. Look at the damage to that top end, that damage all goes in the oil filter rotor and some out the left side steel mesh filter.

will be sure to do all of the above. thanks, man.

We can also discuss your kickstarter gears if a shim for the engagement of the gears or back cutting them has been done with good results. Especially when you replace the top end with a greater compression piston than OEM. This area has been a demon of 83/84 and 85 200X's. The 86/87 200X solved that issue.

the bottom end with the bad kicker is getting shelved for awhile. the kicker is solid in this bottom end, hence the switch. the auto-x will be a project down the road, using the other frame.

Unfortunately now you know why I suggested the putty knife method. There is occasionally a method to my madness, lol. I have used it a zillion times with nominal to 0 damage.

If you want to try and reinstall the broken fin piece, you can try the JB Weld fabiodriven referred to for fixing gouges, however, a more durable method is to simply buy some of that low temp aluminum rod you might have seen on TV or at swap meets where a guy is “welding” a thin aluminum can with it. It is available at all welding supply stores.

i should have listened. my mistake. i'm ok with not repairing it. it ain't no trailer queen.

OMG, he mentioned oil…can I PLEEEEASE talk about oil now, huh can I?

No. Everyone is getting along.

[redsox]

did i misspeak with hundredths? new to all this, forgive me. largest measurement and smallest measurement. largest being the cylinder.

[DohcBikes]

Ya those are thousandths in inches.

The small measurement you are showing is 2.530" The service limit for the 200x piston is 2.555", which means it is well outside the service limit.

The large measurement shows 2.561" The service limit for the cylinder is 2.563", which means you are BARELY inside the service limit.

You have over .030" piston to cylinder clearance. The service limit is .004" I know this sounds very tight but Honda has very tight clearance on this engine. Stock new they recommend .0007-.0019.

Time to bore and buy a piston.

[DohcBikes]

Also, I want to say to anyone measuring a cylinder, that calipers are not a reliable method. The correct method is to use micrometers and dial bore gauges.

Redsox, I recommend you have a machine shop measure your stuff before you get too discouraged.

[redsox]

ok. i'll double check the measurements in the morning, but, it is what it is. do it once and do it right.

[redsox]

Also, I want to say to anyone measuring a cylinder, that calipers are not a reliable method. The correct method is to use micrometers and dial bore gauges.

Redsox, I recommend you have a machine shop measure your stuff before you get too discouraged.

not discouraged at all my friend. learning all the time. this is cool stuff. i have good connections at a machine shop and will have EVERYTHING double checked. honestly, i really liked the idea of doing it myself, but, whatever. i'll get the thing bored and i'll continue to march. i wish i listened to the old man a little closer when i was younger.

[DohcBikes]

Well hey, you got the right attitude. Feel free to pm me with any specs you need, but I'll be following the thread.

On the bright side....your math was right after all lol...its 3 hundredths clearance

Have the machine shop give you the measurements in inches and mm.

Mm should be to the thousandths to be accurate in my book. Inches should be to the ten thousandths, or four decimal places, to be accurate.

[Dirtcrasher]

.300 is allot.

.250 is 1/4 of an inch off. You gotta to be reading .025 and .030 about half and about Two thirds of a MM respectively.

I have inside and outside micrometers 1-12".

Give me a buzz after the micrometer makes some sense.

I see just under 2.530 and 2.561.

Vernier calipers have to be the WORST way possible to measure near anything important; They make a great ruler even with dropped pressed.

You need the inside cylinder measurements in numerous different areas to have an idea if it's within tolerance or not.

Inside telescopic bore gauges and a micrometer set as well are the only way to do it.

When I was 16yo, I went to see the resident moto mechanic and he let me work for him for him. He would drop a .005" long feeler gauge between the bore and piston and smile. New piston based on his visual inspection, the slop was noted as well. There near always barrel shape..........

[barnett468]

Hello redsox;


WARNING: The length of this post may induce drowsiness.

…do it once and do it right.

lol, this comment is gonna come back to bite ya in the backside.


Ok, if the piston/cyl clearance is in fact more than around .010", it is highly likely that the crankshaft ball bearings are excessively worn AND the rod bearing is excessively worn. This is because it typically takes a LONG time to wear a piston/bore out that much PROVIDING it has not ever had much sand run through it. Well, it is a DIRT bike, of course it has had sand run through it, plus it's 50 million years old, lol.

Irregardless [see how I got that word in there Dohc] of how the piston/cyl acquired so much wear, the wear is an indicator of probable excessive wear on the bearings also.

No one wants to hear this, but based not only on the age of the bike, its unknown service history [aside from knowing the piston is orig] and excessive piston/cyl clearance, I suggest you take it apart, replace the crank ball bearings and probably the rod bearing and check the wear on the gears. It might shift fine for ten years as is, it might shift fine for a day.

You can do the following while it is assembled if you want to try and get a rough idea of the crank condition.

CRANKSHAFT BALL BEARINGS – grab the end of the crank one side at a time, see if there is any up and down or in and out play. It should be virtually 0 by feel.

ROD BEARINGS – Check the clearance between the rod and crank with a feeler gauge. Service limit is .031”

Check the radial clearance in the bearing by feel. Service limit is .002”. This is next to impossible for an inexperienced to do properly and judge reasonably well, however, if an inexperienced person can determine with certainty that there is play in this bearing, it is most likely well beyond its service limit imo.

See examples of procedures in the manual in the link below if you do not have one.

http://www.oscarmayer.net/atc/manuals/

Have the machine shop give you the measurements in inches and mm.

Or just use the free online conversion calculators or math calculators which are available at http://math.com.

MM X 25.4 = INCHES

INCHES X 25.4 = MM




This section is more useless than the previous.

GOOD - At .030" clearance, at least it won't seize.

BAD - At .030" clearance, it likely wont have enough compression to run.

GOOD - If it doesn't run, you're less likely to fall off it and get hurt, plus it will save a lot of money on gas.

GOOD - At .030" clearance you can just buy a .030" over piston and shove it in there which will save you money on boring it. [That's a joke too.]

i'm ok with not repairing it. it ain't no trailer queen.

Uh, yeah that’s kinda obvious if you plan on putting that nasty lookin cylinder on it without cleanin it.

Hey Dirtcrasher, please don’t hang me, it’s a joke, [sorry couldn’t help myself], lol.

From Websters online dictionary.

joke [noun]

definition:

Something said or done to provoke laughter or cause amusement, as a witticism, a short and amusing anecdote, or a prankish act.

No. Everyone is getting along.

KILLJOY!



PS - Hey, I don't know if this has been mentioned yet but it might be a good idea to measure everything, lol.