Tag Archives: AG200 chain guard

O’ring chains on the AG200. Really?

Some people that have recent history with the AG200 might be surprised to learn that the first model released way back in ’83 – ’84 was supplied with an o’ring chain for the final drive. What?! Why go to all the trouble of designing a fully enclosed final drive system and then add an o’ring chain? Yamaha must of asked themselves the same question because they stopped doing it not long after the original release. What about now? Is it worth the expense to prolong the life of a component that, if maintained correctly, will last for ages? My thoughts on the matter follow…

Chain gaurdI have some dealer friends who swear by putting o’ring chains inside the chain enclosure of any AG200 that passes through their workshop. If you are a belt and suspenders type of person then I guess you would consider this a good idea. On farms that get chopped up by cattle (deep, sloppy mud) during the winter (Dude…get an ATV!), this is probably a good idea. The factory chain enclosure is great when set up right but it’s not perfect. The lower guard has a drain hole at the lower section and if this part fills with mud and the drain hole blocks then you have a factory chain and sprocket destruction device!

An o’ring chain will not enjoy being operated in a bath of corrosive, abrasive slime but it will last way longer than a conventional chain. So in this sort of environment where people tend to not give the bike even a fleeting glance between times when the bike stops running (known by a lot of farmers as the “service interval”), then I would suggest an o’ring chain a wise investment.

Now for the rest of us…I have never bothered with an o’ring chain on my AG200s because I know how much power conventional o’rings can suck out of a small engine. I don’t know about you, but if I have a bike with less (waaaaaaaay less!) than 20 HP out the back wheel then I don’t want to let any of that go! The AG doesn’t have much horsepower to start with so sucking a little bit out with an o’ring chain wont do it any favours. I also believe if you look after the chain guard properly then it will do nearly as much to protect the chain as any o’ring will.

Some of these new, low friction X ring chains might work better for the AG but once again, vigilance and preventive maintenance, in my opinion, will prevent the need. There is no horsepower to stretch the chain, so if you keep it adjusted, lubed and relatively clean, which the factory enclosure will do, then you are safe with a conventional chain. Spend the money you saved on chain lube and live happily ever after!



Special parts #2!

OK, OK…maybe there are a few more special parts that I forgot about! I’m sure there is more – watch out for “special parts” #3, #4 and #5 πŸ™‚

Fork boots

Fork boot#1

Check ’em out! Most people look at them and go “huh?” Yes that is a vent hose running up into the headlight housing. I have only ever seen this system before on the AG two stroke Yamahas, which aren’t interchangeable either due to their smaller fork diameter. After you get over the initial confusion, its not a bad system when you think about it.

Back in the days of conventional forks, most manufacturers installed boots to protect the fork slider’s delicate chrome from damage and to keep the majority of mud, dirt and dust away from this surface. This helped the dust covers protect the fork seals for an acceptable period before the seals would inevitably fail.

Fork boot#2

The problem with conventional boots is that they had to let the air in somewhere so when it compressed, it didn’t blow a hole in the boot. To prevent the pressure build up, holes were made in the lower sections so air could move freely in and out. Doesn’t this defeat the purpose of the boot thought? Doesn’t that air movement suck dust in? And if mud and/or water did get in, wouldn’t it stay in? Well yes, sort of.

The designers of this this system were probably assuming that dirt bike riders would check them after every ride and clean them out…bad assumption! They didn’t make this mistake with their AG bikes though, they knew farmers wouldn’t clean or check them!

So this was their solution. A fully sealed fork boot with no way for air build up or easy access to grit. Simple and effective until the boot failed, which is quite common and they are expensive of course. If you wanted to be a total maintenance Nazi, you could put a filter sock over the end of the tube in the headlight, but I would never do a nerdy thing like that. πŸ™‚

Rear sprocket guard

Sproket guard#2

Sorry for the grotty rear drive hub, but in an up coming post I intend to do a full strip down of my clean AG (see above pics) and show the assembly in detail. This little bit of plastic that you see on the left is usually nice and white and clean, but it soon gets like this when enclosed in the rear chain guard.

I think that one of the reasons people rip off this chain enclosure (see parts #1) is because (a) it’s a pain to get back together, and (b) I don’t think most people know this plastic part is even in there! If heavy grass, baling twine or wire gets hooked up in the rear drive (quite common) and left to it’s devices, it will chew up this part.

Sproket guard#1

So? What’s so important about this thing I hear you ask. Well, if you change your chains and sprockets and manage to get the enclosure all back together OK but don’t replace this guard, then dirt, mud and water pass easily into the enclosure where it is convenently stored to keep your nice new shiny bits in a bath of corrosive, abrasive slime. Your new chain and sprockets will soon disintegrate.

Next time they pull them off to do the chain and sprockets again they work out or see for themselves this phenomena and write the assembly off as useless. The reality of the situation is that this bit of plastic stops crud getting into the drive enclosure so you really need to replace it if it is worn for the system to work.

AG200 specific but surprisingly it doesn’t cost too much. Good one Yamaha!



Those special parts…

The AG200 is a bit of a “bitsa” as we like to call them here in Australia. Yamaha borrowed an engine and chassis from one model (XT?), which in itself had origins in early 80s thinking in dirt-bike technology (YZ, IT, TT?),Β  and then added what they learned from their 2-stroke AG range – seat, tank, ergonomics, suspension, carry racks etc.

What this means is that there are quite a few interchangeable parts from other models that therefore can be shipped from the USA much cheaper than the local dealers. This can make AG200 ownership a lot cheaper. But this post is not about what you can get from the US, but rather what you cant. I will talk about AG200 parts interchangeability in an up coming post, but for now, lets talk about what parts are confined to the AG that cannot be ordered from somewhere else. You must check the condition of these parts if buying because they are special to the model. Yamaha knows this and rip you for it via their dealers! Might I suggest that if you own an AG200 and the following parts are on your bike then look after them because sometimes they are worth more than the bike!

1 – Chain guard.

Chain gaurd

Why do so many owners rip these things off? I actually know why because they can be a pain to get back on after a chain and sprocket replacement, something to cover in an upcoming post! – quite easy when you know how. Anyway, lots of people knock these guards as useless but trust me; when set up correctly they increase the life of your chain exponentially. In-fact, I’d go so far to say that if you put on a good quality O’ring chain and keep it reasonably maintained it can last indefinitely with normal AG usage…excess power isn’t going to wreck it!

These two pieces of pressed, spot-welded mild steel are absolute rocket money from your friendly Australian Yamaha dealer. And I think they are a must-have for an AG200 to run at its cheap-as-chips low maintenance best. Who wants to be throwing a $100 chain and sprocket set at a $300 to $500 bike every twelve months?

If your bike hasn’t got them try and scrounge a set. If a potential purchase hasn’t got them get the owner to find them and if not, knock the price down or walk away – seriously!

2. Rubber chain guard dust cover.

Dust cover

WhileΒ  we are down at the chain guard, check the condition of the rubber dust cover. Is it split, cracked or missing? Same as above…rocket money from Yamaha, and a pretty big job to replace too.

3. Muffler.Muffler

No big deal you say, just whack on an after market job. Seen the price of them? Seen the quality of them? There are only a few options out there and they aren’t real good. The original Yamaha unit is the best looking, best fitting, and the quietest but is probably the poorest in longevity. The price? I often wonder if Yamaha has ever sold any?

4. Pack racks.

Front rackNot a big deal really, of all the things listed here they are probably the easiest to find because they have been similar since day one, don’t rot out and therefore can be found off wreckers. Just watch out for the good old shovel holder Rear rackmods! The front one suffers from “The Teenage Son Effect”, from henceforth onwards named TTSE. What is TTSE? If the farmer has a teenage son…check the bike out carefully. If the AG200 has been mercilessly flogged and crashed, the front rack always seems to have crazy dings, twists, buckles and other unexplained phenomena! πŸ™‚

5. Fuel tank.

Gumby tank!

Yep, they rot. Later ones fit on older bikes OK but they look a bit gumby unless you match the paint. Check out this recent Ebay sale at the left – I told you. πŸ™‚ Apart from a different fuel tap, paint and graphic decals, they are the same thing.

6. Seat.

An AG200 with a pristine seat is a rare thing indeed. Not hard or expensive to get re-covered but as per usual Yamaha charge a premium for the cover.

7. Emulsion tube/Needle jetCarb parts

I have not had the privilege of ever owning an AG200 from new. I have owned plenty of second hand ones though and most have ran poorly due to a worn out needle and/or needle jet (emulsion tube). With poor fuel filtration from the factory and neglected air filter servicing, these components wear out and the engine runs in a poor, rich condition. This improves immensely when replaced but I suspect it still runs too rich. Another topic for further discussion!

I am looking feverishly for a replacement for the item sourced from Yamaha because this small, simple set of brass components is hideously priced from them and it appears the Mikuni on the the AG200 is also a specific item particular to the model.

8. Voltage regulatorRegulator

If you keep an eye on your battery maintenance, you can keep on top of this one. If you don’t they will cook your battery and fry the regulator and maybe damage the wiring and/or stator. And per usual, Yamaha bite hard for the original item. Also a topic for an upcoming post!

This is not an exhaustive list by any means for specific parts for the AG200. It is the main ones to watch for though and a good start from which I can update in future posts if any more issues come to mind.