Q's on Pics of [Intake port],[Piston skirt],[Reed Valves]

[TheGDog]

Hey Guys, right off the bat I'd like to thank you guys so far for all the wonderful help/direction/guidance.

Man.. after all this work before I can even go out for my 1st ride... it's gonna make it that much sweeter.. :cool:

The Bike
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1990 KDX 200. :ride:

The Scenario :blah:
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Among the many parts that have come in... I've got a set of Boyesen Power Reeds to put on... eventually. Tonite I drained and removed the Fuel Tank

Then I removed the carb (since I have to remove it figured I'd spray all thru the inside of it with Carb Cleaner and inspect/document the jets inside, later on... before putting everything all back together).

Then I removed the old cracking weather-checked intake boot (I have a new one to put on in it's place).

Then I removed the Reed Cage.

When I looked down the Intake port it looks like dirt or something is stuck to the roof of the intake port!?


The Questions :ugg:
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-- I learned that the petcock doesn't shutoff completely, so need a new one, Where to buy a petcock? Are they all similar enough? Is this something I should look for on Sudco.com? Do I have to order this from dealer or from eeeh bay?
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-- RE: Cleaning out the Carb. Is that basically all I have to do is carefully disasemble... generously spray carb cleaner thru all the orifices... let dry.. then put it back together? Or do you have to roto-rooter any of the orofices with something?
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--Can you all please look at the pics of the crud on the intake port. It looks to me like it's dirt!?! I'm thinking whatever that is is NOT right and SHOULD NOT be there. What's the best method for removing this crud?... keeping in mind I wouldn't want it falling down into the engine.
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--Can you all please carefully look at the pics below and look at the part of the piston skirt which is visible and tell me if that small amount of scuff marks is OK...???... or do I need to install a new top-end kit? Or should I just install a new top-end kit anyway since I just bought this bike used? How much does a Wiseco piston kit cost for this bike? What's the best/cheapest place to buy it from?
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--The gasket material between the Reed Cage mating surface and the intake port mating surface did not remain intact. Do I have to use a pre-cut gasket for this application? Or can you use whatever that liquid gasket stuff is I've seen used in other areas of the bike? If you can use some sorta liquid gasket stuff... what's the brand name? What's that stuff called and where do you buy it?
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The Reed currently installed on the Reed Cage. Can you tell if these are the original reeds? And... from looking at how Boyesen would like me to install their reeds... it looks like these are installed the REVERSE of that~! Is that the normal way?? and Boyesen just engineers theirs differently..?... or is this just more evidence that onw of the previous owners was a lame-ass?

ARGH... it told me too many pics on the post... so I'll break them up to one each on subsequent posts....

 

[TheGDog]

Gunked-up intake port. Note the top surface. :whoa:

 

[TheGDog]

Note the piston skirt scuff marks. Is this within the range of normal? Should I start thinking about doing a top-end job?

 

[TheGDog]

The Reed Cage. Are these the original reed valves? Are these installed upside-down?

 

[know_fear]

I'll take a stab at this to get the ball (and the bike ) rolling.
The reeds seem OK but the intake port should not be black like that. Something nasty may have been going on there.
Photos are a great tool but no one will be able to give you a thumbs up on piston wear from a photo. Take the pipe off. with the fingers of one hand in the exhaust port and the other hand in thru the intake port, push the piston back and forth. If you feel any play with this method it's probably too much!
Let's see what others have to say but I would pull the cylinder off and take the piston and cylinder to a bike shop to have them assess the condition. Re-plating may be required. They can tell if the bottom end (con rod big end and main bearings) are good by inspection as well.
It's a huge mistake to put a new piston in when the bottom end is going. If you get lucky it will just vibrate badly as a warning but if ignored you could destroy the engine cases.
I'm not trying to freak you out. You're going about this the right way. Disassemble it while taking notes and photos so you can put it all back together. Determine which parts can be reused but don't cheap out by ignoring advice from mechanics that actually examine the parts.
Good luck.

 

[TheGDog]

Hmm..... I was more concerned about the... um.... oatmeal-colored?? deposits I saw on the top of the intake port. They are the ones which looked out-of-place.

The Reeds don't look like they are installed upside-down as far as which petal was placed on top? I only ask because I compared it against the directions included with the Boyesen Reeds and they instruct to put the Reeds on the Cage in the reverse order. However, I will say their reeds are designed differently, and it's readily apparent visually. So that's probably why.

 

[IndyMX]

The reeds look like they are installed right in the picture..

The reeds in the pic look like Boyesen Pro Series reeds..

 

[jason33]

reeds - yea there in right from the pic-
i would replace them with the carbon fiber -pro series
the port looks like black pain- nothing big- clean it-
cylinder -looks like normal cold starting ware in there
you ca use sctochbright or sand paper to polish the cage area- get all the crap out of there

 

[TheGDog]

Looked back again at that intake port.... "know_fear" you are definitely right... it should not be black at all. My bad... I can see that now.

Dang... do they normally get that blacked-up with this many years old??.... or if this one just really bad for some out-of-the-norm reason?

RE: Using Scotch-Briote or SandPaperto remove the black deposits... which grit SandPaper? And... more importantly... how the heck do I prevent the debris from dropping down into the cylinder and bottom-end? ... OR ... is it just a given now that I'm gonna HAVE to take-off the Head and Cylinder?

------

Man... I have NEVER had to take a dirt bike apart this far before. It's a pain in the butt... but... at the same time... kinda cool and interesting. And the really neat thing is that now that I'm older... and since this bike is an old cheap used one... I have no fear at all of jacking something up.

I actually think I'm going to have a sense of pride/accomplishment once this project is done.

One thing for sure... I'm learning about how certain tear-downs require that you have other parts on hand before you begin. For example... taking out the Reed Cage... the gasket between it and intake port... doesn't remain intact... er.. at least.. not after 17 years... anyway.

And ohhhh MAN! Some of these dang Allen bolts... DAMN!... somebody went all Gorilla on'em when tightening them down... ***** MAN!! felt like I was gonna snap a 6mm Allen T-wrench trying to remove the Front Disk Caliper this evening. I had to utilize a box-end wrench on one side of the T-Handle to cheat and get a TON of leverage... and at a certain point... with a Snap! it finally broke free and I could then undo it.

And God Bless the guys that came up with Brake Part Cleaner spray... and Carb Cleaner Spray... I've been using that sh!t everywhere. This bike will not look at all like it did when I bought it off the previous owner.

One thing for sure is that it was a real bad purchase on my part. For the amount of money and time I'm going to have to pour into her... I'll probably never be able to sell this thing for anywhere near that dollar value.

Meh... oh well.... now it's turned much more into the principle of the thing. I don't want the original money spent to have been a waste.. so now I feel committed to bringing this baby back to like, and then some!

 

[know_fear]

Hold on!

Don't use any abrasive on that intake area unless you already have the cylinder off! Any grit that gets in the bottom will undo all your efforts in short order.
Those stains shouldn't affect engine performance anyway but Id want to know what caused them. Was there an ignition timing issue in the past that caused a backfire thru the carb?
Gaskets-I've had good luck re-using certain gaskets like the reed cage, clutch cover, and ignition cover. If you tear it on disassembly toss it out but smear a little Silicone gasket sealer on each side of the new one. This helps it peel away from the surface without tearing.
Bolts-I always use blue Loctite and never have a problem. I know what you're thinking " Loctite.....there too tight now!". Steel bolts into aluminum cases form a layer of oxide over time that sets up like crazy glue. Thats the white or yellow powder you see on the threads. The Loctite seals the threads so the oxide doesn't form. It also prevents the bolts from vibrating out so you don't need to use so much torque on them when things go back together. Just make sure to use the blue "service removable" blue version, not the red.

 

[TheGDog]

NO doubt on the blue LocTite. I use that stuff on just about everything if I think it's something that would most likely fall-off from vibes. And especially if it falling off with cause something to fall into the engine.

Question... is it possible to remove the head and cylinder without having to drain the brand-new transmission oil I had recently put into her before I began the tear-down?

Question... Head Gasket and Cylinder/Cases Gasket... will the previous ones on there most likely tear apart like the Reed Cage one did? If they are most likely to do that I'd rather have the new replacement ones in-hand even before I even begin attempting that portion of this tear-down.

 

[IndyMX]

NO doubt on the blue LocTite. I use that stuff on just about everything if I think it's something that would most likely fall-off from vibes. And especially if it falling off with cause something to fall into the engine.

Question... is it possible to remove the head and cylinder without having to drain the brand-new transmission oil I had recently put into her before I began the tear-down?

Question... Head Gasket and Cylinder/Cases Gasket... will the previous ones on there most likely tear apart like the Reed Cage one did? If they are most likely to do that I'd rather have the new replacement ones in-hand even before I even begin attempting that portion of this tear-down.

The trans oil doesn't come in contact with the crankcase, so it shouldn't be a problem at all to take the cylinder off without draining the trans. I've done it on my CR many times.

 

[know_fear]

As IndyMX said the trans oil will be fine. The transmission is separate from the crank.
The base gasket cannot be re-used but they're only 4 or 5 bucks. I think your head gasket is the metal type and they can be re-used if not damaged upon disassembly but use an aerosol spray adhesive gasket sealer on it. You'll need new circlips at the wrist pin as well but they're cheap.
When you have the cyl. off you should disassemble the powervalves and you may find pieces in there that need replacing.

 

[TheGDog]

Aw crap... to take off the Head and the Cylinder.. I'm gonna have to drain the radiator too aren't I?

What's the proper steps for doing that? Umm... I assume you have to just put in new radiator fluid each time you need to do this... right?

 

[TheGDog]

As IndyMX said the trans oil will be fine. The transmission is separate from the crank.
The base gasket cannot be re-used but they're only 4 or 5 bucks. I think your head gasket is the metal type and they can be re-used if not damaged upon disassembly but use an aerosol spray adhesive gasket sealer on it. You'll need new circlips at the wrist pin as well but they're cheap.
When you have the cyl. off you should disassemble the powervalves and you may find pieces in there that need replacing.

I don't necessarily have to remove the piston after I've taken-off the cylinder.... do I? :whoa:

 

[know_fear]

You'll have to if you want to check the clearance between the piston and cylinder.
Once you have the piston off the con rod remove the rings then take the piston and cylinder in to your local shop to see if the piston or plating can be re used.
Have you heard the saying "In for a penny, in for a pound" refering to the British monetary pound? A proper rebuild may not be cheap but it's better value that 2 bit rebuild. If you're going to keep the bike do it right but if you plan to sell it then it may be better to go no further than you have already.
A piston sells for around $115. Cylinder plating (if required) is around a couple hundred and a bottom end rebuild is probably 3 hundred more but the feeling of a good strong engine that you saved from the junkpile..........priceless!

 

[IndyMX]

I don't necessarily have to remove the piston after I've taken-off the cylinder.... do I? :whoa:

No.

 

[maxrevs666]

I've seen pistons on th bay for about $80...

 

[TheGDog]

Cool... I'll see when I get the cylinder off. It was running plenty strong once I had changed the plug. the only reason I am at this point now was because the intake from carb to cases was weather-check so I wanted to replace it and put in new reeds while I was at it.

Don't think I'll be replacing the piston unless my eyes and my guts tell me something different once I look in there.

Man... this is all takin' forever too cuz da Wifey's BDay is coming up and I'm throwing at party at the house.... so you know how that goes... ya gotta spruce-up everything inside the place, outside the place. We've only been here since March and hadn't even got framed pictures up on the walls yet because we had to deal with the baby being born and yada yada.

Dang man... it's gonna feel good once I finally... finally get over to the other side where it's all back together and runnin' sharp. It's turning into a money pit.. for sure... but oh well... at least I'm learning things along the way... and I'll know she's solid and reliable once done.

And I'll be damned if this things doesn't have the nicest seat I've ever sat on, on a dirt bike before! No more Monkey-butt!

Well.... less anyway. :)