My Savage hates me!

[Jray2955]

I think my Savage hates me.....

 

It has a K4.6 in it and I started another thread about the pull start incident, stripped the engine down and I have chunk missing out of the piston skirt where I assume its hit the back plate at some point.

With the exhaust off you can see at TDC the crown has a small piece broken off and doesn't cover the exhaust port, which I am not sure whether it should or not.

Unbelievably the liner hasn't a mark on it and I don't know how.

Question is should I run it or get a refund for the £50 I've just spent on parts and put a F.36 in it and be done.

At this point I just want to drive it I've driven it the grand total 4 minutes and am loosing the will to live.

 

Let me also just say this is my first nitro car and my first rc car in about 20 years so I'm also tempted to shove in on a shelf and buy a £100 rtr electric truck just so I can play with something.

What are your peoples thoughts?

Risk it and run it?

Buy a new engine ?

Give it the middle finger and buy a FTX 🤣

[locky]

When removing the backplate the piston needs to be at top dead centre otherwise the backplate will catch on the bottom of the piston and crack it as the backplate is pulled away.

You can see a groove on the backplate where the bottom of the piston will sit when it is at the bottom of its stroke

 

I would get a new engine, buying used engines is a lottery and I dont think your got lucky. 

[Jray2955]

OK I think I'll admit defeat chuck this 4.6 on the shelf and get a Force .32.

Just want to enjoy it as this point!!

[Nitroholic]

I think a replacement motor is the way to go.

 

The piston is supposed to cover the exhaust port in order to generate compression before the mix ignites. It really sounds like this engine has had it, or at least, it's going to cost money to replace what you know is broken, and may have other nasty surprises waiting for you.

 

I have had a .32 in one of my Savages for quite a while, and I reckon it's the sweet spot between grunt and thirst. 

[Grogg]

I've heard that the nitro Savages, the over 20 year old originals, as well as their new ones can be extremely temperamental, though are one of the best if not best basher RCs once you get the nitro dialed in - it's fuel tank design for example is terrible and has been a complaint since it was originally released.  It's why I went for the electric version instead, even though the electric was a little more expensive.

[Jray2955]

Thanks guys, I took your advice and changed the engine out.

To be honest I'm regretting buying this Savage as it's cost me well over £300 at this point and it's just issue after issue, I can't get the engine to tune and think it might have an air leak, I've had the input shaft nut come loose despite being threadlocked and damage the clutch bell and spur gear and the brake work for about 10 minutes and then don't.

It's all stuff that needs tinkering with and sorting out but when I've only had a few hours fun out if it and it needs even more work doing it makes me think I should of brought a new one for another £150 😅 

But there you go live and learn etc.

[Nitroholic]

On a Force motor, especially if it's brand new, there are 2 places you could potentially have an air leak.

 

1) The carb neck. Loosen off the pinch bolt, slide the carb up a few mm, and apply a very thin bead of good quality silicon instant gasket. Set it back in place and retighten the pinch bolt. DO NOT overtighten. The pinch bolt stops the carb coming out, it doesn;t seal it.

 

2) The backplate.  Again....pop out the 4 screws holding it on, and apply a thin smear of the same. Then replace and do up the bolts.

 

Now...the brakes. There are a number of different brake discs you will find on a Savage. Some work well...and some of the aftermarket ones are junk. I prefer the red fibre discs with stock pad. A lot of folks will reccommend all sorts of aftermarket setups, usually involving carbon fibre etc. Don;t bother. Some will work well in the dsry, some will work in mud, some cope with dust .... but they all compromise. Stock works just fine as long as your brake servo is up to the job. If you still can't get the brakes to your liking....google Savage OFNA brake mod. What this mod does is to get rid of the odd servo saver setup and use a double rod linkage as more normally dound on a buggy. The brake then pulls more directly.  I ran this setup for a while on my ...well..nearest stock Savage until I mid-tanked it.

 

As far as things like fuel flow issues you will read about....this is a factor of the shape of the fuel tank and how nitro RC's use exhaust gas to pressurise the tank. If you look at the stock tank, the lower bit has a lot less surface area, causing a change in fuel pressure when the tank gets near empty. It's easy to avoid issues....just don;t run it that far down 🙂 The Mid Tank mod gets rid of the receiver box, which you replace with a flat plate to support the steering servo. Then you use a buggy tank. You then need to re-mount the throttle and brake servo to the rear, which allows a simpler brake and throttle run. It's not an easy DIY mod, and you won;t be able to buy an off the shelf kit....but it has a range of benefits. I did it to put hte tank in a less vulnerable position.

 

My less stock Savage runs a twin .28 nitro setup. 1/5 scale steering servo to cope with silly big wheels and fat tyres. Single speed Flux gearbox with steel spur, rear tie rod deletes and a fully beefed up driveline. It has a Kyosho Gigacrusher air filter setup...which looks like a supercharger inlet, sticks through the bonnet...and feeds the carbs.  That was the end result of owning Savages starting with a 25 ..... The only Savage project I have left to try is to find a way to hook up a 26cc CY motor to a Savage chassis and drive. It will be rubbish, and probably too heavy....but who cares!

[Jray2955]

I suppose it just takes time and patience, what I should of done from the start and what I'll do now is pull it down the nothing change out the bearings regrease everything etc.

Where I'm the UK can I get parts for it?

The big bulk stuff I can get from ebay or similar but I want somewhere where I can order from a parts fische or something similar?

Do you know where I can get gearbox parts from as well?

[wolfie1]

There you go https://www.hpiracing.com/en/instructions/160100

[Jray2955]

Thanks can I just quote part numbers to a hpi dealer?

[wolfie1]

12 hours ago, Jray2955 said:

Thanks can I just quote part numbers to a hpi dealer?

Yea, what i tend to do is go to a modelshop website such as wheelspin or modelsport and put the part numbers in the search box, you can even put the part number onto ebay or amazon although you will need to put in hpi then whatever the part number is

[Grogg]

KT has a video where he talks about and shows you how to deal with the issues the old nitro savages have, it's worth looking up and watching before parting with any cash.

[Jray2955]

Sorry who is KT?

 

[Grogg]

Kevin Talbot, he did a video where he gets a 20 year old nitro Savage to work again and talks about all of it's known issues and quirks and how to deal with them all, like the bad fuel tank design and material choice.  It really is worth looking for and watching even if you're not a fan of him or his style of videos and content.

Edited May 15, 2023 by Grogg

[Jray2955]

Ah ok ill look into it.

 

I've decided to strip the Savage down and rebuild it only way to be sure, so what grease should I run in front and rear diffs and gbox?

Also what mods should I buy or do while I'm in there just so it doesn't break again in 5mins?

 

 

[locky]

Stock servos arent really strong enough so get 35kg+ for steering and 20kg with quick speed for throttle/brake. The plastic steering servo arm will strip so use a metal arm. Check all bearings, you dont need to get hpi ones, just use the bearing size and order from eg. rc bearings etc.  Shim the diffs so that there is no side-to-side play and front-to-back for the bevel gear. Any thick grease will work in diff, such as redntacky or similar.  The 'ofna' throttle mod is worth doing, used to be an available kit, you need two sliders (fastrax) and a rod which you cut bend to replace original throttle rod. You can use the existing servo arm after removing the top section. Red fibre glass brakes are best. You can lower c of g by fitting a 10mm length of tubing inside each shock on the shaft, helps handling. Shock oil between 30-45wt depending on your springs and preference. Aluminium clutch shoes with 0.9mm springs. If A tuned pipe maybe better than the plastic exhaust. A 6v hump pack instead of 4xAAs. Check that there orings inside the diff cups. Check slipper pad condition. Usually recommended with it fully tightened, but dont over tighten. Loctite all metal to metal bolts. Check screws in plastic havent stripped. Check engine plate isnt cracked. Check failsafe is set up to prevent runaway. Check air filter isnt full of dirt. Check suspension arms arent cracked at front where hinge pins go.  Check transmission/gearbox, no damaged  teeth, if covered in grease then clean as running dry is ok. 

[Jray2955]

OK have you any recommendations for servos?

[Jray2955]

Oh also most of the screws into the plastic are stripped out, they grip but you can't get a good tight nip on them.

What's the common process for repairing, go over size on the screws or something?

[locky]

Try cutting a short length from a small zip tie, place in stripped hole and retighten screw making sure zip tie is sandwiched between screw and edge of hole.

[Cactus]

Savages are kool, get a new engine, I have a K4.6 in one of my Savages and an LRP.32 in the other 🙂