Restoration Project #8 - Huge Bundle of HPI, Kyosho and HSP.

[gandalfnz]

KE15 w/stock carb, which I'm pretty sure is a rebadge of a Force .15 engine. I wound up swapping it back from the TT engine, it seemed redundant with the TT-Fish. The other cars I'd sat for a season fired up and had no issues.

Plastic carb body which is ok I guess, but I do generally admire the metal ones more. Appreciate the tip about the GX carb, I snagged it for ~$45 which seemed extremely reasonable.

It was very reliable before, so it does seem like it's one specific issue and not a general malaise of the engine. Definitely true about the low idle, though too low seemed prone to stalling after WOT runs.

The smallest silicone o-rings I can find still have a 4mm OD, slightly too much for carb needles which I believe need 2mm or 3mm OD rings, which that store has in NBR rubber. Might be worth picking up to do replacements with anyway, and its dirt cheap.

I have seen the V2 FW06 idle so nice and low, I blew me away.
Like in this video, FF to 11 mins 20 secs to see how it idles, did you ever manage to get yours to run like that?

I am still not done with my investigation as to why Force 18 carb was sticking/binding, because after installing an SH18 carb (fully metal), same issue, I literally have to apply ARO to the carb slide for it not to bind, its like the slide gets washed with pure methanol and then sticks after that. Hard to explain. I wanna try GXR15 carb now, prob this coming weekend.

What is your general procedure for tuning, in detail how do you tune LSN?

Regarding the O rings, the ones (some have two) on LSN are super small, much smaller than HSN.
I like buying Traxxas Carb rebuild kit, as it comes with a dust boot and lots of different sizes of silicone and rubber seals.

 

[tudordewolf]

I have seen the V2 FW06 idle so nice and low, I blew me away.
Like in this video, FF to 11 mins 20 secs to see how it idles, did you ever manage to get yours to run like that?

I am still not done with my investigation as to why Force 18 carb was sticking/binding, because after installing an SH18 carb (fully metal), same issue, I literally have to apply ARO to the carb slide for it not to bind, its like the slide gets washed with pure methanol and then sticks after that. Hard to explain. I wanna try GXR15 carb now, prob this coming weekend.

What is your general procedure for tuning, in detail how do you tune LSN?

Regarding the O rings, the ones (some have two) on LSN are super small, much smaller than HSN.
I like buying Traxxas Carb rebuild kit, as it comes with a dust boot and lots of different sizes of silicone and rubber seals.

Wow, that is an amazing idle. I'd gotten mine running pretty nicely, maybe not quite that nice.

I tune LSN first, then HSN, then adjust low again. I try to run as rich as possible without impinging on performance.

My tuning process: assuming this is a broken-in engine that was running well last time it was taken out.

I'll start the car, usually setting the LSN slightly richer and the idle gap slightly higher to make it easier to start, then bringing both back down a little.
I'll give it some throttle blips and see how it responds, leaning it out if it seems sluggish coming out of idle or richening it if it seems like it's bogging once the throttle opens up a little.

Once I've got it so that I can give it 3 quick blips and run it around without it stalling, I'll start doing WOT passes and adjusting the HSN, first by ear, then based on the shift point. If it's taking too long to reach second gear, it probably needs to be leaner, and I also check the temperature after every pass.

 

[gandalfnz]

Wow, that is an amazing idle. I'd gotten mine running pretty nicely, maybe not quite that nice.

I tune LSN first, then HSN, then adjust low again. I try to run as rich as possible without impinging on performance.

My tuning process: assuming this is a broken-in engine that was running well last time it was taken out.

I'll start the car, usually setting the LSN slightly richer and the idle gap slightly higher to make it easier to start, then bringing both back down a little.
I'll give it some throttle blips and see how it responds, leaning it out if it seems sluggish coming out of idle or richening it if it seems like it's bogging once the throttle opens up a little.

Once I've got it so that I can give it 3 quick blips and run it around without it stalling, I'll start doing WOT passes and adjusting the HSN, first by ear, then based on the shift point. If it's taking too long to reach second gear, it probably needs to be leaner, and I also check the temperature after every pass.

Each to their own when it comes to tuning.
Is there are reason why you go for LSN first, or touch those needles at all once set the first time you tune it?
Personally once I tune the car, I usually never have to touch LSN or idle again, only HSN, quarter of a turn leaner or richer.

Up the idle to about 1mm, no need to measure this.
Since overall fuel intake is dictated by HSN (affects LSN as well), try adjusting HSN first, a few WOT passes and you can hear when engine is running good.
When HSN is done, see how quick it is on take off, you are looking for a snappy start, so once brought to a stop, I leave it idling for about 5 seconds and then apply full throttle, if take off is sluggish I will then start leaning the LSN. Once take off is good, most likely engine idle high, due to LSN being leaned out, I then reduce the idle, and that's it!
Takes me about half a tank to do all this, since I preheat the engine before starting, so no need to waste fuel warming it up.

You should end up with a car running like in this video, this is a GXR15.
This is my Kyosho S3 and it was tune as per method I explained.

 

[tudordewolf]

Is there are reason why you go for LSN first, or touch those needles at all once set the first time you tune it?

Mostly because I'll get stalls on what seemed like a previously good tune, and at idle / low speed rather than WOT. This is leading me to believe that either the idle gap or LSN are set incorrectly. It runs fine in the higher throttle ranges, good performance and temps held between 200 and 250, so it feels like the HSN is set correctly.

At this point I think it's a mechanical fault somewhere that I'm trying to fix with tuning instead of troubleshooting.

I'm not really adjusting the idle gap every time so much as I am using it to trim-up the throttle during startup, and then I set it back to whatever it was before.

My Thunder Tiger Fish behaves the way you describe, in fact, they were so confident that you wouldn't need to adjust the needles that they used hexes instead of flat heads for the needles & idle screw, and even put in the manual that the carb should hold a tune once set, and so far it has.

The weather I run in varies from 60 deg F and 50% humidity to 90 F and 80% humidity, so I'm not surprised that I have to make some adjustments between outings.

I basically can't start my engines without preheating; I might be using that heat as a crutch instead of learning a more robust startup / tune.

Up the idle to about 1mm, no need to measure this.

If I do that and it idles too high, should I assume I have an air leak / cracked o-ring? That was kind of my experience. I was having trouble getting the idle down without outright stalling the engine. It'd run at a high idle, but perform inconsistently if I tried to lower the gap, although it was already quite "small"

 

[gandalfnz]

Mostly because I'll get stalls on what seemed like a previously good tune, and at idle / low speed rather than WOT. This is leading me to believe that either the idle gap or LSN are set incorrectly. It runs fine in the higher throttle ranges, good performance and temps held between 200 and 250, so it feels like the HSN is set correctly.

At this point I think it's a mechanical fault somewhere that I'm trying to fix with tuning instead of troubleshooting.

I'm not really adjusting the idle gap every time so much as I am using it to trim-up the throttle during startup, and then I set it back to whatever it was before.

My Thunder Tiger Fish behaves the way you describe, in fact, they were so confident that you wouldn't need to adjust the needles that they used hexes instead of flat heads for the needles & idle screw, and even put in the manual that the carb should hold a tune once set, and so far it has.

The weather I run in varies from 60 deg F and 50% humidity to 90 F and 80% humidity, so I'm not surprised that I have to make some adjustments between outings.

I basically can't start my engines without preheating; I might be using that heat as a crutch instead of learning a more robust startup / tune.


If I do that and it idles too high, should I assume I have an air leak / cracked o-ring? That was kind of my experience. I was having trouble getting the idle down without outright stalling the engine. It'd run at a high idle, but perform inconsistently if I tried to lower the gap, although it was already quite "small"

Don't worry about the idle being too high, as long as the car is not rolling on its own, if it is, then just back it out a little. You want the idle to stay high so it does not die on you as you describe from being too rich.

Sometimes you may think it is, but there is still room to lean, as it could be your HSN affecting your LSN and idle by being too rich. Try leaning the HSN a bit more, or until you get lean bogs, this will not damage the engine, because you will richen it right back.

Once you are sure HSN is set, move onto LSN, richen it or leave as is, and see how the car behaves after sitting for about 5 seconds and you apply full sudden full throttle, if it hesitates and is sluggish with logs of smoke, start leaning the LSN until you get crisp and snappy take off after idling for 5 seconds. If you think the LSN is too lean after setting the HSN, then back it out and repeat the process.
I don't bother with fuel line pinching and then counting until it shuts off, for me this is amateur way of doing it and is never consistent.

When LSN is good, then as a last step, lower the idle until it purrs nicely....that's it.

When you take out the car out again, after you know you had a good tune, don't try and fiddle with LSN and idle, rather lean or richen the HSN, that will usually do the trick!

From experience, Kyosho engines really need a small idle gap, unlike HSP and HPI.

To check for air leaks I do a very simple test, before putting the carb into the engine, I attach a fuel intake tubing, close the air/fuel intake holes with my fingers and blow, you will hear air hissing if there was an air leak worthy of a concern.
I do repeat the same, once the carb is in the engine, blow and listen, and usually the front engine bearing will leak a bit of air, but this is normal, and should not be a concern, unless you have a puddle of fuel on your chassis after you are done running.
Make sure again, you plug all the obvious/normal air leak holes with you fingers.
Sometimes I can hear a hiss, but can't figure out where is coming from, I will submerge the whole engine into a bucket of water a and blow.

 

[gandalfnz]

Any luck with your tuning issue?

I am getting close with that Force Engine, but different parts just keep dying on me, then its another few weeks wait to get the parts from China.
Right now, clutch is working great, but the 2 speed has shat itself, the little claw that pops out and hits the pin on the spur gear is worn, and it just goes over it.

On the bright side, I got myself a broken GXR15 for $10 USD, basically mainly because of the carb. can't miss a deal like that.
I have also acquired an old vintage Kyosho GS11 engine, single needle carb, and I noticed piston sleeve is not silver coated from the inside?
Got it for cheap, its brand new, I love getting engines like this every now and the, as they always come in handy in later projects.

 

[tudordewolf]

Nice find with those engines, that GS11 looks crisp. Would be really good for a vintage car.

I haven't the FW-06 out again yet, had a rainy week, will probably get to do that this week.

The rear-exhaust Fish is coming along nicely, got the engine mounts & clutch squared up:

The rear-exhaust truck's stock exhaust would hit the suspension, so I ordered the manifold for the OS 18/21TM, then discovered that although it fits over the exhaust port, it doesn't have enough clearance for a silicone gasket to fit, so I've ordered some high temp O-rings from Ali and hopefully they'll do the trick.

 

[tudordewolf]

Right now, clutch is working great, but the 2 speed has shat itself, the little claw that pops out and hits the pin on the spur gear is worn, and it just goes over it.

I keep a baggie of those since they're ~$2, and as you see, a common failure point.

I've had some last a really long time and others wear out quickly, I'm not sure exactly what's up, maybe differences in the hardness of the claw or the pin pressed into the gear that it engages with.

 

[gandalfnz]

I keep a baggie of those since they're ~$2, and as you see, a common failure point.

I've had some last a really long time and others wear out quickly, I'm not sure exactly what's up, maybe differences in the hardness of the claw or the pin pressed into the gear that it engages with.

Yea, I don't know, its one of those things, it was working great when it was all stock, and since the engine upgrade, a lot of parts start to fail, prob just a coincidence.

Maybe its the shifting point that wears them out quick? I noticed that Force18 is making the car shift earlier, by quite a bit.

I have ordered myself 5 of those complete 2 speed clutch/claw units.

 

[gandalfnz]

So, I repaired the broken 2 speed claw, by flipping it over, drill a new pivot hole on the other side, press the pin it, and it looks like it will work just fine.
In fact I filed a bigger pivoting angle than stock, so now it should come out a bit more and engage the spur pin with a meatier part, rather than just the tip, if that makes sense?

Haven't tested it yet though...

 

[tudordewolf]

Oh, that's awesome! I should've held on to some broken ones to try that. I'll probably have more soon enough...
That particular part might be the FFish's Achilles' Heel. It works though, and the simplicity makes it easy to troubleshoot and repair.

 

[gandalfnz]

Oh, that's awesome! I should've held on to some broken ones to try that. I'll probably have more soon enough...
That particular part might be the FFish's Achilles' Heel. It works though, and the simplicity makes it easy to troubleshoot and repair.

When I was drill the pivot hole into the claw, you can tell the material its made off is quite soft, no wonder it deforms after a while.
To machine a claw like that out of a stainless steel washer, or something harder shouldn't be too much of a problem, I would think.

 

[tudordewolf]

When I was drill the pivot hole into the claw, you can tell the material its made off is quite soft, no wonder it deforms after a while.
To machine a claw like that out of a stainless steel washer, or something harder shouldn't be too much of a problem, I would think.

That's interesting, it definitely seems like a part that should be hardened. The pin pressed into the gear definitely is.

Other manufacturers seem to have gone for beefier shifting mechanisms, Kyosho's FW-06 uses a 2-shoe clutch:

 

[gandalfnz]

That's interesting, it definitely seems like a part that should be hardened. The pin pressed into the gear definitely is.

Other manufacturers seem to have gone for beefier shifting mechanisms, Kyosho's FW-06 uses a 2-shoe clutch:

View attachment 165825

I am surprised to see the spur gear is still there any not damaged, looks weak and brittle.
Clutch being the way it is is good in a way, because you will always be able to macgyver it.

 

[gandalfnz]

Another version of FFish?
That force engine seems to be running nice in that video, maybe its my tune that needs some work....

 

[tudordewolf]

Another version of FFish?
That force engine seems to be running nice in that video, maybe its my tune that needs some work....

I believe that's the VRX onroad nitro, aka RH/Riverhobby. Model RH 1004. I figure they're the main competitor to HSP, seems more common around Europe.

Looks like the fuel tank is the same but the other bits are different.

Also it's C-link without a pivot ball version offered... Looks like a more solid C-link than HSP's, but I've been sold on pivot balls.

Digging into their spec sheet it looks like it uses the same clutch bell with a 45/50 transmission, higher reduction than either of the HSP ones. If it fits in the same footprint, which it looks like it may, that might be a cool upgrade for something I want to put bigger wheels on, maybe "truggify" my buggy.

I am surprised to see the spur gear is still there any not damaged, looks weak and brittle.
Clutch being the way it is is good in a way, because you will always be able to macgyver it.

I've destroyed a few HSP 2-speed gears with bad mesh, once I got it dialed in I've done 50mph without even leaving a mark on the gears, they still look new:

I purchased some steel 2-speed gears from Ali, but they're so heavy I decided to keep them for a truck build or something.

 

[gandalfnz]

I believe that's the VRX onroad nitro, aka RH/Riverhobby. Model RH 1004. I figure they're the main competitor to HSP, seems more common around Europe.

Looks like the fuel tank is the same but the other bits are different.

View attachment 166029
Also it's C-link without a pivot ball version offered... Looks like a more solid C-link than HSP's, but I've been sold on pivot balls.

Digging into their spec sheet it looks like it uses the same clutch bell with a 45/50 transmission, higher reduction than either of the HSP ones. If it fits in the same footprint, which it looks like it may, that might be a cool upgrade for something I want to put bigger wheels on, maybe "truggify" my buggy.


I've destroyed a few HSP 2-speed gears with bad mesh, once I got it dialed in I've done 50mph without even leaving a mark on the gears, they still look new:

View attachment 166031

I purchased some steel 2-speed gears from Ali, but they're so heavy I decided to keep them for a truck build or something.
View attachment 166030

Yes, looks like a premium version of the FFish.
That second speed spur looks nice with that engagement pin being completely metal.
I assume that the centrifugal clutch (fully metal one) is still the same, and would most likely suffer the same fate by "claw" wearing over time.

Interestingly I have never suffered a damaged spur so far, I adjust the mesh by feel, and leave a bit of slack.
I would usually loosen the engine - chassis mounting bolts, then press the spur and the bell tight, then roll it back, and let them mesh themselves so that there is no noise coming from the mesh, then re-check and tighten. Sometimes the between them can seem a bit big, but as I said, never had an issue.

My FFish with a reversed/modified clutch claw is ready for testing. I have received 5 brand new clutch units, but decided to give this one a go, and manufacture a new claw out of hardened stainless steel later on.

 

[gandalfnz]

11k carb arrived, it fits the Nitro Slash just fine, no need for mods.
I guess I will be testing it soon and posting a vid on how it runs.

 

[tudordewolf]

11k carb arrived, it fits the Nitro Slash just fine, no need for mods.
I guess I will be testing it soon and posting a vid on how it runs.

That's great news! Looking forward to seeing it run.

Sorry I don't have more updates on my own stuff. As an aside, I noticed something interesting about the difference between the C-link and pivot ball versions - the wheel bearings are only spaced ~3mm apart on the C-link hubs, but almost 10mm apart for the pivot ball one. This explains difference in 'play' and wheel stability, in addition to the stiffer positioning the pivot balls provide.

Top is C-link stub axle, bottom is pivot ball, with bearings placed where they would be when installed.

 

[gandalfnz]

That's great news! Looking forward to seeing it run.

Sorry I don't have more updates on my own stuff. As an aside, I noticed something interesting about the difference between the C-link and pivot ball versions - the wheel bearings are only spaced ~3mm apart on the C-link hubs, but almost 10mm apart for the pivot ball one. This explains difference in 'play' and wheel stability, in addition to the stiffer positioning the pivot balls provide.

View attachment 166184

Top is C-link stub axle, bottom is pivot ball, with bearings placed where they would be when installed.

Really good you have both for comparison, that would make a big difference in how stable they are!
Tested the Fish today, shifts beautifully, then realized that the it was only hitting the side of the spur pin, so claw is already damaged. Damn!
Clutch assembly needs to be moved as close to the spur as possible, before tightening the grub screw.
Man, what else can go wrong with this thing....