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Rebuilding My Old Savage 21

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I don't even know how to fix it. We took it all the way apart minus taking the piston out. Which I think can be done? We will take it apart and I'll post pictures.
 
You can remove the piston/sleeve. The sleeve has to come out first. You can try a piece of brass sheet big enough to fit in the exhaust port and try and turn the crank over with the flywheel on Pinch the brass with the piston to push the sleeve up.. It should pop up when you turn the crank. If not then you will need to heat the block and try again. put in oven @400 for 15 minutes and try again. Once you pop it up remove the brass sheet and remove it the rest of the way. then you can remove the piston and see what is the problem.
HPI Savage X F4.6 PISTON, SLEEVE & CONNECTING ROD (Engine Carburetor 4.6 | eBay
I don't recommend liquid wrench as a engine lube. Use Hobbico after run oil.
The 3 speed new is $200-300
 
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Ok, just took apart the motor. Here's what we found. What does that tell you about the motor? My buddy feels as though there is a spacer missing. The manual doesn't explode the motor.
 

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There should be 2 copper shims under the head. The discoloring is from high nitro with no castor oil in fuel. What do the bearings look like. ? How is the condition of piston/sleeve? Push the piston threw the sleeve manually and see how far it stops from the top? Remove the starter and crank and inspect the bearings. If you have to remove the bearings Put the block in the oven and cook @400 for 15minutes. then remove the inside back bearing firs by slapping the back of engine on counter top and it will drop out. The front bearing is a little harder . Slap it on the carb opening it will pop out. If not heat again until it pops out.
HPI Racing K 4.6 Manual (Page 3 of 16) | ManualsLib

As for it binding before with the roto starter on I think it didn't line up correct?
HPI Savage X F4.6 PISTON, SLEEVE & CONNECTING ROD (Engine Carburetor 4.6 766150469691 | eBay
 
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No copper shims. Everything was removed totally. Bearings are good. I think the starter crank is possibly bad, if that's what it's called. The piston goes close to the top, very close when done manually both in the case and in the hand removed from the case. It is hard to do though. There's alot of resistance. And we were turning the motor by hand. Never got the roto start on it. Which if I had charged the battery pack like I should have done we would have tried it. But it's charged as of this post. So is my igniter. Cause we are going to run my old motor on the new truck.

Side question, we had to put the carb from the 4.6 on my 3.5. Cause my 3.5 carb is totally frozen. Is that 4.6 carb to big? Or will it work and we just need to tune it?
 
You should be able to unfreeze the 3.5 carb. Remove the idle screw and carb boot and use after run oil on the outside and inside of the throttle barrel and let it sit a while. Gently rock the barrel back and forth in and out until it loosens. lite tapping will work too.

Motor you needs the copper shims.

On the backplate there should be a disc with a slot in it to align to the crankshaft pin for the starter. I don't think the starter shaft is bad? That slides in to the back plate and one way bearing turning the disc with the slot. Make sue the slot aligns with the pin on the back of the crankshaft when you put in on.

Put it back together and see what happens?

Fuel run at least 14% oil lube with 2% castor oil. The engine will stay cleaner and not gum up and lock over time.
Air plane fuel usually has castor oil in it. Don't buy car fuel unless it has castor oil in it. Your wasting your money with car fuel and quarts. Gallons are cheaper.
 
I bought a quart on Amazon that has oil in it. I just forget the percentage right now. And I'll look at gallons from now on. I have to order online ss no one here in Phoenix sells it anymore. Which I find very lame.

Later today we will look at the motor again. It's still totally taken apart. I'll have to look at the part number in the manual and order the shims if they are needed that badly, unless you have another fix for that in mind such as a very thin washer?
 
All nitro fuel has oil in it. You need fuel with oil lube and castor oil. Most Hobbytowns will carry fuel or will order it to store. Yes you will need the shims without the engine will not run properly.
 
Only place here with rc stuff is hobby bench and they carry no fuel or glow plugs. Is the oil thing something new? Because when I use to run my savage I just bought what was in the store and was never told about anything different like the castor oil. Can I add that to it myself?

I'll take a look at home depot to see if I can find the right size shims. Or something to use like that. I'm at the point of wanting to get this done. And I'm getting impatient with waiting on shipping.

Just frustrated.
 
Most of the Hobby shops I see are on the outside loop. Scottsdale and Gilbert both have Hobbytowns. It may be a drive but worth it. Prepay a case and I'm sure they will get it. That's were I have to go now as shipping fuel is expensive. I order 3 cases ever 4 years.
#15228 GASKET SET FOR CYLINDER (0.15mm/0.3mm) (hpiracing.com)
 
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Hmm, never heard of hobby town. I'll look them up. See if I can do online orders. Didn't know you were local. Or are you just looking stuff up?
 
I went to the hobbytown website and it says no store is close. I'll look at the one you said. The hobbytown USA instead. Ordered the shims though.
 
Ok, so we got it running. Not the 4.6 but my 3.5. And we actually ran it around the yard. It flies! But we are still trying to get the fuel right with the carb. It's fickle. But then again it's the bigger carb from the 4.6. So right now I'm soaking the 3.5 carb in a solvent to loosen it up. We shall see if that works. I'm optimistic. But still cautious.

I was told by someone on a Facebook group to get gt85 fluid and put a little of that on the 4.6 and he would help me with the rest. I have no clue on that. A little help with that? And I already have the shims on the way.
 
I have always had good luck with after run oil. I just soak it and work it a little at a time. The stock settings for the 4.6 carb should be fine. This is why I use fuel with castor oil. It doesn't freeze up carbs like this ever. It coats the parts and they stay free a long time.
 

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