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Kyosho engine help

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Hypno

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Hi, all

First post!

So I dug out my old Kyosho 1:8 Volvo S40. This one, I believe: https://www.rcscrapyard.net/kyosho-landmax-volvo-s40-racing-31871.htm

It has a Kyosho GS21 engine, from what I can tell.

Back when I bought it, me and my father never quite got it to run smoothly, and thus it was used very little. Getting help wasn’t as easy back then either.

I thought it was long gone, but just realized it still existed, and I started taking it apart and cleaning it up. I’m having a go at the engine first. To begin with, the piston was stuck, and after getting it unstuck, I couls hardly turn the crankshaft from all the oil residue in there. After a thorough rinse with some wd40 the crank shaft spins fairly freely, but I would still like to take it out to give it a proper clean.

Now here comes my question. I can’t get the crank shaft to budge. I tried heating the engine and goving the black pin there a thud with a wrench and pushing it against the table, to no help. Any ideas? It may be stuck in the bearing. I am afraid of hitting too hard because I don’t want to damage anything.

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Last edited:
Hi, all

First post!

So I dug out my old Kyosho 1:8 Volvo S40. This one, I believe: https://www.rcscrapyard.net/kyosho-landmax-volvo-s40-racing-31871.htm

It has a Kyosho GS21 engine, from what I can tell.

Back when I bought it, me and my father never quite got it to run smoothly, and thus it was used very little. Getting help wasn’t as easy back then either.

I thought it was long gone, but just realized it still existed, and I started taking it apart and cleaning it up. I’m having a go at the engine first. To begin with, the piston was stuck, and after getting it unstuck, I couls hardly turn the crankshaft from all the oil residue in there. After a thorough rinse with some wd40 the crank shaft spins fairly freely, but I would still like to take it out to give it a proper clean.

Now here comes my question. I can’t get the crank shaft to budge. I tried heating the engine and goving the black pin there a thud with a wrench and pushing it against the table, to no help. Any ideas? It may be stuck in the bearing. I am afraid of hitting too hard because I don’t want to damage anything.

View attachment 243549

View attachment 243550

Put it in the oven at 300F for about 25min.
Remove with the wife’s least favorite oven mitt.

Holding crankcase firmly, whack the face of the protruding crank snout against a block of wood. Obviously you want this to be a SOLID, and SQUARE whack. Be mindful of the crank jumping out, and landing on your arm, or vinyl flooring…😅

The only downside to this, is the main bearing coming out with it. If it does, it’s not a big deal-just will still need to be removed from the crank. -and of course; reinstalled into the crank case.

Soak everything in a good solvent for a couple hours, and clean up with an old toothbrush.

To reinstall the bearing after it’s been properly cleaned, put the main bearing onto the crankshaft, and leave in the freezer for a few hours. Now toss the crankcase BACK into the oven at 300-350F.

Drill a hole in your block of wood big enough for the crank snout to pass through, but small enough to still rest the front bearing face against the block of wood.

Bring everything back to the block of wood, and carefully reinstall. The crank snout, and front bearing will help to align the main bearing.

Allow to cool, then reassemble.
 
Last edited:
Hi, all

First post!

So I dug out my old Kyosho 1:8 Volvo S40. This one, I believe: https://www.rcscrapyard.net/kyosho-landmax-volvo-s40-racing-31871.htm

It has a Kyosho GS21 engine, from what I can tell.

Back when I bought it, me and my father never quite got it to run smoothly, and thus it was used very little. Getting help wasn’t as easy back then either.

I thought it was long gone, but just realized it still existed, and I started taking it apart and cleaning it up. I’m having a go at the engine first. To begin with, the piston was stuck, and after getting it unstuck, I couls hardly turn the crankshaft from all the oil residue in there. After a thorough rinse with some wd40 the crank shaft spins fairly freely, but I would still like to take it out to give it a proper clean.

Now here comes my question. I can’t get the crank shaft to budge. I tried heating the engine and goving the black pin there a thud with a wrench and pushing it against the table, to no help. Any ideas? It may be stuck in the bearing. I am afraid of hitting too hard because I don’t want to damage anything.

View attachment 243549

View attachment 243550
I love your RC!!!! KYOSHO RULES!!!!
odoyle rules.gif


Do what @Littlemotor said and you'll be running great in no time!

Try to include some favorite salad tongs or a nice wooden spoon to be sure your wife is REALLY on-board with your RC addiction!!!
(or maybe not depending on how on board she is right now. 😉🤷‍♀️🤣)

WELCOME TO RCTALK.COM!!!👍😁😎
 
Thanks for the detailed and throrough response, @Littlemotor! And I’ll make sure to use as many coveted kitchen utensils as possible in the process, @CertifiedMike :)

I’m going to give this a try, and then I’ll let you know how it went.

Again - thanks! Really appreciate the input!
Absolutely brochacho-there’s nuthin to it. 🍻🤘
 
Thanks for the detailed and throrough response, @Littlemotor! And I’ll make sure to use as many coveted kitchen utensils as possible in the process, @CertifiedMike :)

I’m going to give this a try, and then I’ll let you know how it went.

Again - thanks! Really appreciate the input!
Hopefully then its not too late for me to mention the 'duck and run' method of avoiding flying kitchen utensils???!!! 🤕
This can come in handy at an amateur steak house too. 😉

Good luck!!! I'm so happy you decided to save your KYOSHO!!! ( They RULE!!!) 😎
I can't wait to hear how everything goes once its running again! 👍😁
 
The "bake it in the oven" trick worked like a charm. Had it in there for 15 minutes and gave it a small whack with a rubber mallet, and the crank shaft came right out. The bearing, however, won't budge. I tried sticking the crank shaft in the freezer and directing a torch to the bearing, but it still didn't move.

I have cleaned everything with various brushes and break cleaner, and the main bearing has gone from hardly turning to spinning freely. I am starting to think that I might just as well leave it on the crank shaft and install it again once the engine block is clean (that 20 year old black goo sure is tough). Anyone see any problem with this?

Went to an rc shop today and bought a new spark plug and air filter, so progress is slowly being made.

Thanks for all the great help, guys!
 
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