Well, at least these stone-age Fuji's are... Really cool little things. No power whatsoever, but absolutely fun.

They look the part, run and make noise. What more could you ask for?

Just in case this 6.5cc isnt good enough are there still outboard engines being made ?

Ok so the info I read was for the larger displacement engines.

Maybe why the original owner got rid of it... Run it and see how it runs... I know the cam valve timing will not be identical between the two cylinder for performance reasons... they must have changed the cam profile after it went into production from the prototype Clarence reviewed.

From horizon
$43 for the front cam
$32 for the rear cam

Are the two cylinders supposed to have different valve dwell times?

AFAIK yes. I think OS has one and there might be a few more. But they are all "flexdrive-type" outboards, not geardriven, and I simply don't care for those. It has to be "real"...

The valve opening duration may be different between cylinders, not sure, haven't measured it. The lobe separation angles do have to be different between cylinders on twins however. I'm not 100% sure why but have heard it's because the cams spin opposite directions and the intake and exhaust ports are on opposite sides. Still makes no sense to me explained that way. But then, I can be about as sharp as a basketball at times.

Thats part of the reason, and why the cams can't be interchanged, if they could they would have the same part#... exhaust valves open early before bdc on the power stroke to blow down the cylinder combustion pressure before the piston starts the exhaust upstroke... thats done so the piston doesn't start to re-compress the expanding exhaust gases, which rob power from the next cylinder's combustion / power stroke., valve duration effects overlap and exhaust reversion / and induction standoff.... saito's known for their aggressive cam profiles, they mimic RW engine performance profiles why I was surprised the prototype shared the same valve timing for both cylinders
.
I only owned 4 saito's,. a .50GK, 1.30TD, 1.50s, and 1.80 NIB.... gave the 1.50s to a flying buddy, and sold the 1.80, I never had plans to used it, as I like the larger giant scale aircraft... I dislike the AAC's so I stopped purchasing saito... and they continue to disappoint with the 100TS having composite cam lobes.... otherwise they're nice performing engines.

Thanks John, helpful info.

Having a closer look at the 2 two cams yesterday it appears I was wrong, the lobe separation is the same, so close I can't see a difference without measuring. The cams do have different part numbers, true, but it may be only because the timing marks on the gears are in different places?

So, thinking on this further there is a difference between an even fire flat twin and this even fire IL twin.
On an even fire flat twin the right cylinder configuration is identical to a single cylinder engine i.e. the cam is turning the same direction and the ports are on the same side. The left cylinder has the cam turning the same direction but the ports are reversed. That's what dictates the need for two different cams, each having different lobe separation angles. That's what I'm hearing anyway. So:

The front cylinder of the even firing 200 IL twin is configured just as the left cylinder of a even firing flat twin i.e. cam rotating same direction as a single but with ports reversed. The rear cylinder (when viewed from the rear of the engine) has the ports on the same side as a single HOWEVER, the cam is rotating backwards. This where things get confusing to me. Wouldn't the front and rear cylinders then use the same cam but get timed differently? The two cams I have appear to be just that, same cam profile but with different cam timing mark locations.

Sorry about the way I write, I'm not the best at communicating my thoughts.

The valve opening closing would be similar... If thats all the differences between the two cams is just the timing mark, then its unusually for the $10 price difference between the two... the 200Ti front cam is from the left side cam of the odd fire 182 twin, that cylinder's valve timing / cam profile is the same as a single cylinder... the 200Ti rear cam could very well be just the timing mark reference index, but I believe there is a difference in valve opening closing timing by a few degrees between the two cylinders... Degree the front valve timing with the cam set on its timing mark in reference to TDC, and then rotate the crank counterclockwise 360 degrees (prop rotation) and see if you can dial in (degree) the rear cam valve open closing in degrees and disregard the cam timing mark, if you can't then the cam profile, valve opening closing, duration and overlap will be different between the two cylinders.

No sir, the right cylinder of the 182 uses the same cam as the singles. But, but, BUT, you brought up a good point, the 182 is ODD fire. I failed to remember that. Things are beginning to make sense now.

I installed the 200ti rear cam into the front cylinder using the cam indexing hole, just in case the previous owner swapped them. The crank angle was 180° off.

Just for curiosity sake, I will degree both cams again, this time using a more accurate "final word" indicator (.0001"). The .001" indicator I used for previously measurements is not accurate enough to detect "a few degrees" difference in crank rotation.

Completed mounting the engine and hooked up the cooling lines.
Got a 12v (fuel) pump and am wondering if that could help avoid overheating the engine?
There is about 2c between the screw and that pick up tube that is suposed to provide pressure for the cooling system.
Also hooked up a fuel tank with muffler pressure.

boat bowels

What is the belt used for?

It goes into the groove on the flywheel and around a groove on the starter cone of a electric starter on the other side.
Then you are supposed to hold the starter up and press the boat down to get enough belt tension so it does not slip.
Once the engine is running tuck it away from moving parts like under the engine.
Older generations helicopters like the shuttle also where started with a belt.

Shows how much I know about RC boats. Zip...

I have the cams timed correctly in the 200ti, I think. The "dot" index mark on the front cam facing straight down, the "dash" index mark on the rear cam facing straight down. The dot and dash index marks are 90° cam rotation apart, 180° crank rotation. Seemed logical, so I went with it.

The valve train movement is very close to what I would expect to see, however the rockers are not level with one another at TDC of the exhaust stroke. They are close but not perfectly level. It would take 1/2 of a tooth of cam rotation to make it them level, which of course is not possible. Bottom line, I would run it like it is.

Everything is set up to measure the opening and closing events later this afternoon.

Edit coming:

This came with a batch of rc things that included a almost complete raptor30 heli kit (reason i bought it) a crashed ego30 heli (stripped it down for engine and servos) and a unbuild multiplex "smiley"
It was "stored" in a damp (leaking?) shed for years and if i would not have bought it, it likely would have been trown out.
The picture below was one of 2 of the ad and that was all the info avaiable.
Had to do a lot of cleaning just to be able to handle it without getting dirty hands.

Never had a boat before (not really my thing). Getting these old things (about 25 years if not more) working again is a fun project and saves them from being wasted for now.
Btw have no idea what models those fuses belong to there are no wings or even drawings.



random rc stuff

Normally, the pick-up provides AMPLE water to keep the engine cool, don't worry about that Don't forget that for example in your car, the cooling water outlet is kept at a fixed value (usually between 80 and 90 degrees Celsius) by the thermostat, which means that the inlet to the engine usually is well ABOVE 70 degrees.(closer to 80, actually), but your boat engine is receiving water straight from the pond, at maybe 15 to 25 degrees.

No worries, it WILL cool.

I feel the measurements are within +/- 1°. Results are averaged from 4 measurements using a degree wheel, piston stop and final word indicator. Measurements were repeatable within 1 degree.

Front/Left Cylinder:
Intake opens at 46 btdc, closes at 55 abdc
Exhaust opens at 78 bbdc, closes at 25 atdc

Rear/Right Cylinder
Intake opens at 48 btdc, closes at 55 abdc
Exhaust opens at 75 bbdc, closes at 28 atdc

Clarence Lee measurements:
Front and Rear Cylinders:
Intake opens at 40 btdc, closes at 60 abdc
Exhaust opens at 75 bbdc, closes at 25 atdc

She's ready to run when I receive the inserts from Chris.

Many thanks to all that helped!

Thats what I expected, the intake valve opens later on the rear cylinder... works in a similar way to exhaust blow down, but instead improves the induction velocity / cylinder fill... the rear cylinder is the stronger of the two,... the front cylinder absorbs a bit more power, but the two cylinders balance out across the 720 degree engine cycle.

The front cylinder is the right hand cylinder ( starboard side )... and the rear cylinder is the left hand cylinder ( port side ) when viewed from sitting in the cockpit... that's how its described in the RCM Saito 4 stroke handbook for the saito twin cylinder engines...it has some useful information, but unfortunately that book was published before the inline twins were released... I did see someone uploaded a scanned copy in pdf format, but I don't recall where it was posted... it only really matters to the person standing in front or from behind, as long as you have the cylinder parts relationship understood, thats all that really matters.

the valve dwell times are similar for both cylinders now too.

Yes sir. The 200ti however is documented in the inverted mounting orientation, that's how Saito designed it to run. So once flipped over inverted the rear cylinder is the right, the front is the left. Tricky! That threw me at first too.

I would agree that the cam profiles could be slightly different, however this is a preowned engine with different wear patterns on each tappet. One of them is worn into a domed shape and two of them have flat spots at the edges.
As it is, the opening and closing events are measured from just off the base circle of the lobe, so irregularly worn tappets could easily account for a few degrees of crank angle variance when measuring. The only way to be 100% sure is to measure using new parts and zero valve lash.

i'm getting the hang of Fusion. i think i'll print this one in ASA this weekend.

That looks VERY nice Dave. When does production shipping begin?

Some succes and the next problem.
Was able to get the engine to fire but it only runs a short while off it prime.
It does not draw fuel unless i put a finger over the air intake.

In all am verry happy with the result; it tried to escape the tub twice so there is life in the bugger.

No video it where just short burst so no time to start recording