The Cline regulator's diaphragms are compatible with gasoline

I thought the prop hub has a wedge but the engine has indeed a collet without a wedge wich make timing easy.

Sometimes the collet slips (on the glow versions) but eventually settles down

The Saito FG have a key way, the FA series have a collett

The Saito FG series gas engines have a set screw/pin that positively locates the prop drive washer / timing hub. It screws into the hub and extends into a hole in the crankshaft to positively locate the hub

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WOW Saito put their name on that? looks rough! I expect better from Saito.

That would give me a problem with timing. I'll give that extra attention..

Evert1969:

Since the FA82 collet type hub can slip, it's all the more important to mount the hall sensor to take advantage of the slotted adjustment in the plastic sensor housing. Many engines have a convenient round diameter adjacent (right behind) the magnet hub that accepts a simple hose clamp which allows for a lot of timing adjustment. In my Saitoconversion, I found the hose clampideadidn't work because on the Saito 150the bearing diameter isn't contiguous. So I made a complex bracket instead that you'd probably find difficult to do. You may face some hard choices on mounting your sensor, but however you do so, preserve the sensor adjustment capability because it sounds like you may need it.

My Saito 150 gassser conversion ran for the first time yesterday. I only had a chance to run it for a few minutes before running off to see the movie Avitar. I don't have any tach measurements or tuning observations yet. But it sure ran smoothly. Here's a picture.</p>

The standard Saito to ignition conversion has the Hall effect sensor bracket mounted under the two fron screws of the cam box.

The magnet hub is an aluminum collar held fast on the existing prop drive washer by a set screw. If the collar slip initially it is no problem readjusting the timing to 28 degrees. Then it never seems to slip after that.

Jim, same two screws I used for my sensor. The bracket was really difficult to make though.

More run time on the Saito 150 conversion. Today I got 7200 rpms with no tuning on either the high or low. I'm taking things really slowly on this, meaning not changing a bunch of things without a good reason. Getting a tach reading was tricky because the shop lights make every RPM read 3600. It sees the 60Hz flickering. I got around that by dimming the basement lights and shining a flashlight into the prop arc. Irigged a home made engine exhaust vent system in the basement made from a big shop vac because it's -17 degrees in the garage.

My first observations are that the transition from low to high rpm is ok, but when closing the throttle, even gently, the engine quits. Also, it takes an electric starter to get it goingdoesn't want to start by hand flipping like a 2 stroke would.this is after choking with evidence of gas wetness afterhaving done so. Any ideas?

It must be going lean with all that rpm when you close the throttle

Rom?

typo, he meant RPM (the O and P are next to one another)


You aren't running the vac while running the engine are you?

You're having a bad day or just taking a shot? []

From my 180 conversion a couple things are possible:-

Idle speed too low. Sudden shut-down (sudden closing of the trottle) will work if you are at say ~1800RPM or more idle, but will cut if you set the idle as slow as it will go, say 1400RPM.
Carb without check valve. I'm not sure here, it definitely makes a diffence on 2 strokes, but I can't be sure what exactly what occurs with 4 strokes! My SPE26 had a better/cleaner shut-down in the air with a carb that had a check valve.

Another post (sorry!).

My 180 is a lot better with a carb that has an accelerator pump. I couldn't tune it for best-idle/best-pickup on three other Walbros of various venturi sizes.

Accelerator pump made it pretty-much perfect.

Looks like a real stump puller. Sorry.

Greg, I'm missing your point (I posted too many times!). What do you mean?

Keith.

[quote]ORIGINAL: dogshome


According to the WT456-1 parts list, there is something called accelerator kit, piston. Item# 58, P/N 160-510. I wonder if this is an accelerator pump? Regardless, I don't think that's related to this quitting on decel. I plan on doing a decel experiement with the choke in various positions to try to get a clue. Need to know if it's lean or rich at that moment to narrow the possible causes. My money is on lean right now, as W8ye said.

<u>accelerator kit, piston. Item# 58, P/N 160-510</u>

That is the accelerator pump

The Walbro manual has a trouble shooting chart in the service manual that should help with this project.

http://wem.walbro.com/distributors/s...viceManual.pdf


Probably just a needle adjustment, both hard starting and shut down during decel need low needle adjustment

Thanks for the service manual link Nosedragger. As I get more into the tuning piece of this, I'll consult it. Deliberately, I haven't even touched the needles, yet I've noted that the start & run symptoms have grown inconsistent. Never would hand start, but would start with the starter. Sometimes would quit at WOT, sometimes on decel. Sometimes it would start quite wet (carb), other times it would fire not so wet.

This evening, while trying to start it with the electric starter, on a sudden whim, I got brave and reached over the spinning (not running, just spinning with the starter) prop and pushed DOWN on the spark plug adaptor with the rubber end of my chicken stick. The engine CAUGHT and ran immediately, then died again when I let up with the chicken stick. OK this RCEXL P.O.S. is defective on two counts. This intermittency, and the previously mentioned difficulty in soldering. Anyway, I stuffed a second spring inside the shroud and now I can hand start it. Did it twice. I feel rewarded for resisting the urge to start messing with the needles too soon. More running and investigating tomorrow night.

I should mention (since I'm slamming RCEXL) that I emailed my photos from this thread my fix to the soldering issue of the RCEXL 1/4-32 plug shroud (the split brass sleeves) to Paragon, and that guy emailed me that he's forwarded my email to RCEXL to see if they could find a way to reproduce this fix. This is after he told me I'm the first one to have this problem. Really, RCEXL doesn't need to do the brass sleeve. I just did that because I don't have a plating shop in my basement. All RCEXL has to do is tin plate the two carbon steel shroud halves and it would solder just fine. Now, I discover they need to have a longer spring to overcome this intermittency too.

I'm also wondering how the thin con rod and needle bearing are holding up. Soon, It'll be time to pull the backplate for an inspection. I also replaced the super thin pulse line tubing with a larger diameter tube. That didn't help at all (I did this before I discovered the plug making & braking). I think it was starting (sometimes) with the electric starter because that caused the whole motor to shake and vibrate more than hand starting, probably causing the shroud to make contact sometimes. I'm sure the spark was jumping the gap sometime too. But hand starting was too gentle to make any of that happen.

If the spark cannot jump out through the plug wire, it will jump at the sensor. Very much of this and it's bye bye sensor.

At one point during this, I had to replace the batteries. With fresh batteries, the spark started snapping spontaneously, maybe twice per second. It sounded like this was happening at the plug. Within a few minutes, this settled down, but I wondered why that would occur.

I know that if the spark snaps just once when you first turn on the ignition that the sensor is shorted by the spark jumping to ground through it.