Yanclone Throttle Assembly

[pietenpol2002]

Just curious whether any others out there have the throttle assembly on their 10 HP clone as in the links below. The engine shown is a 6 HP but the assembly is quite similar to the 10 HP. It's set up to take a conventional throttle cable which mine doesn't have. I like the look of it and saves me building my own, but Carroll Stream wants $48.65 for it. A bit salty by my standards, but then I'm cheap. Has it worked well for others?

Ron

http://tinyurl.com/cvvsaz

http://tinyurl.com/buuget

[Dan J]

The bottom "wired" bolt that the guy highlights in the video isn't an rpm adjuster, it's max fuel governor. Undoing increases fuel (and smoke), screwing in decreases.

My throttle set up is vaguely similar in that the cable sits in an adjustable screw so the idle can be altered - the problem with my set up, and I'm pretty sure this guys, is that once your throttle cable is fixed in there's no easy way of stopping the engine (can't reduce fuel input below idle). I currently stall mine to achieve this and have the decompressor in case of emergency.

[arnaud]

you regulate the RPM's with the top lever. Set the spring at the most outer holes.
Weld/solder a 3cm. lever on to the top lever,( just a small metal bar, first drill a 2mm hole in the end, you can put the inner cable trough that) pointing to the primary case side.

If you have the primary case directly to the engine like mine, you can(and i advise to) make a stud between the engine and the top 2 bolts where the gearbox is hanging on. This will line out perfectly.
At this stud (piece of 3mm plate or thicker) you can mount the adjusting thingy for the throttle cable.

Next, you remove the big stopper screw for the max. fuel setting and install a smaller screw with spring at the lower lever(the sme it stops to) similar to a carburettor adjsuting screw, and make it touch the peice of housing the original stopping screw was fit.
In this way you can reach and adjust it at the right side of the engine. Otherwise the primary case is in the way..

In order to fit the engine, i had to grind down the rear oil screw and clip the plastic filler screw.

At the lower side there will be 2 ears with holes from the lower gearbox positioning plates. Originally these are mounted to the engine to give the WHOLE LOWER-REAR FRAME THE NEEDED SUPPORT. Do not ignore this.
I welded small triangle shaped plates between these plates and subframe, making it stronger.
Also, i've been yelling enough here about the rigidness of the front side of the subframe...original, the engine is a supporting part of the frame design. Keep that in mind

[sbrumby]

I disagree with Dan as to the purpose of the lower screw, it is external to the engine and the rack on the pump, if this is srewed in it will limit the RPM and thus the fuel. The reason it has a seal on is to stop the RPM going higher than it is meant to.

[Dan J]

Sam - feel free to read the Yanmar manuals at http://dawinfo.com/ to prove my point (see top one, L-A series complete manual).

The governor works in an interesting way on the Yanmar (and clone) engines. The governor is simply a set of weights inside the engine that exert a force on the governor arm pulling it back to rest position with greater force as the engine speed increases. The throttle cable is connected to a metal arm that sits above this and is connected to the governor arm simply by a relatively stiff spring. It is the tension in this spring as you turn the throttle that the governor has to work against and increases the engine speed. There are several holes on both throttle arm and governor arm so you can adjust the spring tension - you move it out to increase the tension (and thus maximum speed of the engine). As the manual states, you use holes further out for 3600rpm (for generator applications) and ones closer in for 3000rpm. See pages 62 and 63 in the above LA manual plus the diagram of governor on p63, Type B.

As you open the throttle, it is the position the bottom governor lever moves to that controls the maximum amount of fuel injected. Thus the lower "wired" screw acts as a stop and controls this. Described briefly in the manual on page 94 and in the right hand diagram on the same page.

For a clearer picture have a look on http://autos.groups.yahoo.com/group/Die ... ike_World/ in the files section - go to Yanma engine information folder and look at the files in there.

Trust me - I've had hours of adjusting the damn things!

[andrewaust]

sbrumby, Dan is actually right, the maximum speed needs to be set with the levers not the main rack adjustment bolt, if you actually force the bottom lever up against the rack adjusting bolt you can easily blow the engine by over revving it, especially with a no load condition.

Its a simple but yet again complex system, I've worked with diesels for many years having qualifications in Mechanical Engineering, specialising in Diesels.

You can turn the bottom bolt in to limit RPM, but you'll have very sluggish acceleration, best to set the bottom bolt to achieve slight smoke under full load conditions, I've found the factory setting to rich and capable of over fueling the engine.

Slight smoking under full acceleration is OK, black sooty smoke is bad, eventually it will kill the engine.

The Yanclone engines are good to 3800 RPM, when running in keep it lower though, Id go for 3000 RPM.





A;)

[Dan J]

>Its a simple but yet again complex system

Definitely - and one it took me a while to get my head around. I didn't understand it properly until I had the bike in front of me and could see what was going on with the engine running. It's almost counter-intuitive - especially when like me you're used to the workings of a petrol.

It's actually a bad set up for our use - the governor linkages are sandwiched between the engine and gearbox and are a bugger to get to if you need to make changes. The throttle cable stretches slowly over time and so needs continual adjustment to keep the idle speed in check. I look at (Diesel) Dave's Enfield with its Lombardini engine with envy - three simple bolts on the front. Max fuel, idle and max rpm. Mind you - I have an extra 6cc to play with to make up for such shortcomings

[arnaud]

Adjustment is easy, but first run in your bike for a couple of thousend kms, then run it warm and screw it in a little, ride and repeat untill you notice decease in power and accelleration, preferable against wind.

Then you turn the adjusting srew 180 degrees out again, and try then.
If nessesary, repeat untill no more power is gained.
If you got the maximal output back, and it doens't smoke a lot, youre' there.
If it smokes again very much at a fixed speed, you need to set the screw a little more inwards.
Smoking while accelerating is normal.
If you can not find this equilibrium, don't worry and ride more. Running in goes accompanied with smoke due to the relative high oil consumption and setting of the fuel pump system.
So, with 10 minutes of tinkering on a desolate straight road youre' finished!

[sbrumby]

Well I think I understand it now, mine & I have two both Yanmars not clones but I presume are the same, the bottom screw has a plunger in the end and as this goes in and out is spring loaded, so this must act as an extra tension against the bottom govenor arm which is connected to the rack ? I pressume this only limits the amount of fuel in normal running because if I leave mine in 3rd gear going up hill when I should change down nobody can overtake as they cant see past me.

[Dan J]

Sam - I followed Andrew's advice to good effect...

If you unscrew the end of the plunger and stick a ball bearing or similar down it then it locks that spring loaded plunger (I guess you could just as easily use a bolt of the same thread in place of the lot of it). It is much easier then to adjust it in and out to prevent smoke under load. If you don't do this it seems to be hard to adjust without subsequently making the idle uneven - I guess a legacy of the engines being set up for static rpms.

It's actually an adjuster specifically for when the engine is under load so (if you lock it) you should be able to play with it to reduce smoke levels. My engine was exactly the same when I first got it - belched out black smoke under load at higher rpm. Now - virtually nothing. Fuel consumption has gone down as well but not at the expense of acceleration (as arnaud suggests you keep winding it in 'til you notice a loss of power, then out a quarter of a turn).

Are you going to the Bat & Ball this year?

[andrewaust]

Exactly Dan, if you are not going to be hassled regarding emissions you can use a bolt instead of the original bolt and locking the pin. I need to use the standard stuff and neatly wrapped the copper lead wire up to look untouched !

The pin is there to give a very rich mixture at low RPM whilst accelerating, when governor speed is increased with RPM the little spring plunger pushes back on the rack to decrease fueling.

I agree guy's, Diesels can be a pain in the butt at times. What stuffed it up for me was the introduction of the electronic common rail. That opened up a new ballgame, one I wasn't going to contend with "more education and lots of cash for individual programs for ECU programming, fault diagnostics etc"

Just remember guys, a little smoke on hard acceleration is OK, lots means excessive carbon build up on combustion surfaces over time which become abrasive resulting in rapid wear failure/seizure of parts.



Cheers


A;)

[dieselbikin]

Here's my current throttle assembly. It works great, but I'm probably going to build a better one soon.



The bottom fuel lever has a plate welded to the bottom. The plate has a small hole drilled in it for a choke cable to pass through. After the choke cable passes through the plate a stopper is clamped onto the cable. As you can see, the plate moves back and forth on the choke cable until the cable is pulled. When I want to shut the engine down I pull my choke cable against the plate which forces the bottom lever down shutting off fuel to the engine. The idle is controlled by a nut and bolt. The nut is welded to the throttle and a bolt is run through the nut. The throttle lever rests on the bolt's end. An extra nut is on the bolt to lock it in place.
Finally, the twist throttle and cable come from a mini bike and the fittings on the end of the cable are from the original throttle. Hope that helps someone.

[dieselbikin]

Almost forgot. My bike has a center stand, so I simply prob the bike up on stand ,which puts the rear wheel in the air, and start it up. I use the rear brake to put load on the engine so I can adjust the fuel limiting bolt in the garage without having to do roadside adjustments.

[Dan J]

Thanks dieselbikin... My governor/"throttle" setup is a little different than yours but you've given me an idea as to how I can achieve an engine shut off - cheers.

[dieselbikin]

For the first time I truly understand how the governor and main fuel rack adjuster work together. Thanks.
I bought a bolt and spring to replace the original fuel rack adjuster. Metric 10X1.25 bolt that is 50mm long. A longer bold would have worked better. Anyway, the bike runs better than ever. This is the first time I have been able to adjust the engine for max power without belching black smoke under load. Very pleased!

[UAofE]

My engine tops out at 2300rpm (but it hasn't run-in yet so it may go up a bit naturally).
If I understand the description correctly, to reach the full 3600rpm I must move the two springs to the outer notches? What is the effect of moving the smaller spring?
The adjustable bolt on the lower right is for maximum fuel quantity and not RPM?



How do I check and adjust injection timing?

[arnaud]

Ehm, i am confused.. i always understood that for 3600 rpm's, the biggest spring should be in the outer holes of both levers?
Do i misunderstand??

[dieselbikin]

Finally got around to updating my throttle assembly.
Added return spring
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Swiveling cable to lever connection
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