Topics

1

Engine and Bottom End / Not your typical oil question: Castor oils

« on: November 21, 2019, 02:59:49 PM »

So all over the internet, you can see debates about various oils, mostly in the categories of Castor vs Petroleum vs Synthetics.  I don't think anybody really runs petroleum-based, so that doesn't apply, and you don't really see many of those arguements anymore.  So mainly, castor vs synthetic.  We can debate those a little here if you want.

However, what I cannot find, but I KNOW was an issue many years back, was SWITCHING to and from Castor oils.

Decades back, it seemed like it was common knowledge that if you run castor oil, you're stuck with castor oil forever.  The castor oil left a "varnish" behind that wasn't an issue with continued castor use, but that "varnish" wouldn't allow a non-castor oil to properly wet the lubricated surfaces (think water beading on a waxed surface), and without sufficient coverage, you don't get sufficient lubrication.  So the common philosophy at the time was that you can always switch to castor oil, but you can never switch back unless you replaced every single bearing.

Has anybody ever heard this?  Or heard this disputed?  Is it because it was all just a myth?  Or is it because that problem may have indeed occurred with petroleum-based oils, but doesn't occur with synthetics?

2

Carburetor, Intake, and Exhaust / ESR exhaust flange O-ring size

« on: May 13, 2019, 11:32:08 PM »

So I wanted to look around for new o-rings for my ESR exhaust flange, and I found a whole lot of people talking about them, but I never saw anybody post any specific sizes.  It was almost like a government conspiracy.  Not that I have a problem with ESRs prices or availability, I just wanted to look for maybe thicker rings, or different (more expensive) materials.

So I'm going to share my thought and findings, because I couldn't find the information anywhere else.

The o-rings I got from ESR are a hair over 0.100" in width, and since 0.103" is a fairly common width for o-rings, I'm running with that assumption.  It's either that, or assume they are metric, and I just don't think they are metric.

It's kinda tough to get an exact ID and OD on o-rings this large, because they don't hold a perfect shape at rest, they're kind of an oval.  I tried measuring the largest diameter at rest, and the smallest diameter, and finding the average.  I'm coming up with about 1.866.  This is subject to a very high degree of error.  This would mean the OD is about 2.072" (by calculation, not measurement)

My calipers don't fit exactly in the groove of my flange, but I believe I'm measuring a diameter of 1.942".  I know I'm going to want my o-ring ID to be smaller, to ensure a tight fit.  The width of my groove is about 0.120"



So I went through charts of o-rings, with the basic assumption these are standard size.  3/32 is a common o-ring size at the previously mentioned 0.103" width, and looking for the ID and OD to match closest to what I was measuring.

The end result is I believe these are a standard size #134 o-ring.  Standard dimensions are 3/32 width, 1-7/8 ID, 2-1/16 OD.  Actual listed dimensions are 0.103" width, 1.862" ID, 2.068 OD.  These are just a few thousands off from my actual measurements, so I'm pretty confident.

3

Body and Controls / Heat shielding/tape

« on: May 20, 2018, 03:30:52 AM »

So I'm tired of deformed/melting plastics.  I've got a couple projects I would like to add some heat shielding to.

So my first question is: What are you guys using for heat shielding?

My second question would be an extension of the first.  If you haven't found a good solution, can we come up with a good solution?  I've done a little bit of research on heat shielding tape, but it seems like any decent product I want to try is sold as rolls of tape, costing hundreds of dollars.  I don't want to spend $500 on 45 feet of heat shielding tape if all I need is 1ft, only to throw $480 worth in the trash.

Maybe a group effort?  Like, collectively we all buy a $500 roll of tape, and we cut/ship according to need?  I'm totally willing to put forth the effort to divide according to need/contribution, but I don't like the idea of buying 45ft if I only need 1ft.

4

Carburetor, Intake, and Exhaust / Let's talk fuels

« on: February 15, 2018, 12:06:34 PM »

I am having the hardest time finding information about different race fuels.

I can find spec sheets, but I'm trying to find the next level, a small glimpse into the chemical makeup and differences.  I don't think any of the manufacturers are going to advertise their exact formula and give away their secrets, I just want to find a little more than the spec sheets.

Somebody told me that VP fuel is paraffin-based, while Sunoco is petroleum-based.  The guy that told me is actually one of the most knowledgeable guys I've ever met when it comes to motosports-related information, so I don't doubt him at all, I just want to confirm it, and find out the differences.  The pros and cons of different formulas and bases. 

5

Carburetor, Intake, and Exhaust / Sealing the pipe

« on: February 13, 2018, 12:58:37 PM »

Anybody ever find a really good way to seal the pipe?

I've got an O-ring exhaust flange, new silicone O-rings, they just end up burnt, brittle, and eventually break and leak.  Same at the pipe joint.

I've had good luck (once) with copper sealant, but I disassembled that pipe years ago, and every time I've tried the copper sealant since, it too has leaked.

Anybody ever have 100% success with something?  Like, actual, multiple successes, not just once?

6

Lounge / Non-250r tech question for you guys...

« on: February 23, 2016, 12:18:00 AM »

So I got this old 1985 Honda TRX250, it's a small 2wd utility quad.  It's shaft-drive, which means some sort of gear drive at the rear axle, much like a ring and pinion on a car differential.

I think this small gear housing at the rear axle got some water or contamination in it, and I want to flush it out without disassembling the whole thing.  Problem is, the gear oil is SO thick, it won't drain out.  I tried heating up the entire housing to thin the oil, but it STILL won't drain.

What can I add to the oil to thin it out, without risking damage to seals and stuff?  I was thinking gasoline, because oil and gasoline are so chemically similar (both being petroleum products).  Or maybe a thin oil, run it for a while to mix, and drain.  Repeat.  And repeat.  And repeat again?  Maybe brake cleaner?

I'm at a loss, I've never faced a problem like this before.

7

For Sale - Complete Bikes / Nice looking, all stock 1988 for sale locally

« on: November 29, 2014, 06:13:25 PM »

It's not absolutely 100% stock, they didn't come with nerfs. And it's not showroom condition, but from the pictures it does indeed look to be in very good, nearly all original condition.

I don't have a whole lot of free time, but I will facilitate the sale of this beauty if somebody is interested in it. It's not mine, I haven't check it out, but if somebody here is interested, I'll communicate with both buyer and seller to finalize the sale, and I'll even donate my time (but not my money) to ship it.

If I'm shipping, you will have to pay shipping fees, any construction material costs for a crate, and also know that I will indeed be taking it out for a spin before it is packed up and sent to it's new home.

http://reno.craigslist.org/snw/4779799692.html

8

Carburetor, Intake, and Exhaust / Educate me on new styles of pipes

« on: July 09, 2014, 11:54:06 AM »

I built my 250r a long time ago, when Yukon gears and OEM cranks were still available.  Things have changed since then.

This isn't a "wut pipe is best" thread, but just an EDUCATION of different pipes now available.

I've got two motors I need to discuss.  I'm thinking a TRX5 centermount pipe for my 340PV, I'm not too happy with this Duncan Eliminator pipe.  But last time I was looking, there was only one style of TRX5 available, now I see talk about a 5 or a 5b.  What's the difference, and the target of each style?

I've also got a dismantled ESR 310 on a shelf I'm gonna start assembling, with TRX9 porting.  So same question on the pipe, because I could swear I saw a 9, a 9r, and a 9b.  What is the difference?


I'm not knocking Eddie, he's done wonderful things for our machines, but his website used to be really informative, now it's just a catalog list of parts with little information (unless I'm looking in the wrong spot).  I'm just expected to "know" the difference in styles and parts.  I know he's busy, so I don't want to bug him with these questions.

9

Carburetor, Intake, and Exhaust / 36mm PWK Air Striker, where?

« on: April 03, 2014, 01:47:25 PM »

I've seen about seventy places that sell 38mm PWK A/S carbs.  Apparently Keihin also offers a 35mm and 36mm A/S carbs, and I've seen a couple of places offer the 35mm because they're targeted at the banshees.

I've seen reference to the 36mm A/S, but I've never seen anyplace offering it for sale, and I'm too lazy to start making a bunch of phone calls just yet.  So where do I find one?

10

Lounge / Modify steering, NOT 250r-related...

« on: March 31, 2014, 02:20:45 AM »

So I just recently acquired a Yamaha Grizzly 600.  It needed a bit of work, but I finally got the last of the parts in and fired it up a few days ago, and took it for a test drive.  I'm really surprised!  It's got a solid axle, and when you start getting up up to speed, it kinda handles like a sport quad.


I don't want a 600lb sport quad.


Mostly it's in the steering, it's really responsive.  TOO responsive.   I'll try some of the easy adjustments first, like tire pressure and toe-on, but I might get more in depth.  I'm not even sure what to call the piece I'm looking at, but the steering stem is in two pieces and this piece that attaches the tie-rods to the steering stem.  If this was a car, this would be the pitman arm, but most ATV steering stems are one-piece so I'm not sure this piece has a dedicated name.

Basic physics says if this part is longer (meaning the tie rods are mounted FURTHER from the steering stem) then small changes in turning the handlebars equals big changes in turning the wheels.  The steering would be very responsive and the vehicle would oversteer.  The opposite is also true, if this part is shorter, with no other changes, then the steering becomes less responsive, and the vehicle understeers.

I'm thinking about cutting it and welding it shorter.  I want the steering to be less responsive, but I'm worried about unintended consequences.  I don't know if this quad is designed with a full Ackerman steer angle, but I would certainly throw that kind of stuff out of whack.  Or the steering might bind up because one part is moving more than another, or other undesirable effects.

Thoughts?  Anybody have any experience modifying or designing aspects like this?

11

Carburetor, Intake, and Exhaust / Looking for 4-stroke power (flame on)

« on: February 20, 2014, 02:36:31 PM »

Go ahead, insult me all you want.

I like to build complete engine combinations.  Engine, carb, pipe, the works, and if I pull it off the bike it all stays together.

So my newest project is a mild-mannered trail machine.  I'm thinking stock cylinder, probably stock porting, 36mm carb, complete intake with snorkel and all, but I can't decide on a pipe.

The goal here is NOT horspower.  It's a smooth, easy, mild power delivery (yeah, like one of them slow 4-strokes).  I don't want to improve low-end torque with a big-bore kit because it will have too much peak horsepower.  This is a trail machine, slow and easy.  I'm basically trying to turn my 250r into a 400EX.

What pipe?  If FMF made the Gnarly pipe for the 250r, that would be my choice, I think FMF pipes are great for stock porting.

12

For Sale - Parts / Complete new CR250 ignition with adapter plate

« on: January 24, 2014, 01:45:01 AM »

I bought a complete system from ESR a couple years back to diagnose some funny ignition-related problems I was having with a motor.  I installed the system, ran it for about eight minutes, then pulled it off and put it on a shelf.  I also have another adapter plate because I have a 98 CR250 ignition also.  In fact, I think the second adapter plate is literally still in the plastic.

Okay, now that I have your attention, I need to be honest.  I'm not  really looking to sell it unless the current market value is a bazillion  dollars, I just like to know how much money I'm sitting on if ever I  needed to finance one of my other many many projects.  I'm not totally opposed to selling it, but I'm not willing to sell it for what I bought it for.  If I wanted the money instead of the ignition system, I wouldn't have bought it.  Eventually I'm  looking to put this ignition on a 310cc duner (of which the cylinder is  sitting right next to it on the same shelf)

But for the sake of curiosity, what is the going rate?

13

Introductions / What hath god wrought?

« on: January 16, 2014, 02:12:35 AM »

Is this where I'm supposed to say hello, and y'all welcome me with open arms?