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Could use some advice on what I think is clutch slip

Could use some advice on what I think is clutch slip

Old 09-25-2017, 05:28 PM
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Default Could use some advice on what I think is clutch slip

Anyone mind taking a look at this video and taking a stab at what you think may be going on?

HPI savage x 4.6, recently installed a dynamite big red .28

Broke engine in, then started melting spur gears, quickly found out plastic ones are impossible to find ao I went with a robinson 16/48 setup. At same time I thought maybe I was slipping clutch before with stock hpi shoes causing spur gear and clutch bell to heat up so I put dynamite max life shoes and 1.0 mugen springs in (3 clutch setup) along with savage stock flywheel. Few tanks of fuel into having fun truck stopped moving with some fun sparks coming from clutch bell area.

Pulled it apart to find a fair amount of aluminum in bell from the shoes. Tried sending it all up, cleaning with brake clean etc, same result, I can part throttle it, but under any real load it spins up. Have had clutch off probably 20 times now, have since went with a new clean Robinson 15 tooth bell, stock shoes, 1.0 springs, just verified that flywheel isnt rotating on crank by paint marking it and looking after it ran and slipped.

When I pull it apart I dont see anything crazy like bell full of clutch, witness marks on flywheel from bell (have tried several different shimming techniques etc).

A few days ago I put a stock 17tooth bell on knowing that the ste spur would eat it. It did, but sure seemed like no slip for the 1 tank of fuel I got out of it.

Anyhow any advice greatly appreciated, I hate to go electric, but trying to have fun with my son who I just got a slash 4x2 and this thing is killing me lol.

Some old pics when I first started pulling it apart of the old bell after some sanding. See anything wrong with my basic clutch setup? The one pic showing spring not in the groove isnt how it is now

Thanks!


Arrr shooot, cant post the YouTube link I dont have enough posts yet.
Attached Thumbnails Could use some advice on what I think is clutch slip-20170911_195848.jpg   Could use some advice on what I think is clutch slip-20170911_200504.jpg   Could use some advice on what I think is clutch slip-20170911_195856.jpg   Could use some advice on what I think is clutch slip-20170911_195834.jpg  
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Old 09-25-2017, 05:29 PM
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I can on a link if anyone is interested
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Old 09-25-2017, 05:50 PM
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So is the clutch bell for the truck, as I had some vented off-brand ones and they seemed bigger, so is the drive train free, as in the pics cannot really see if the clutch bell is turning blue from the heat, as I would see if you had temped the clutch bell, but as for the pics it looks fine

Gotta ask anything out of the normal on driving, meaning tall grass, truck pulls, lots of low speed stuff and or idling for some time???
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Old 09-25-2017, 05:57 PM
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Thanks for answering

It's a Robinson racing for a savage, clutch bell / spur combo. I have a different engine but savage 2 speed trans.

After cleaning stuff up and putting together I'm running it long enough probably at quarter throttle to get engine up y2k temp to see if when I stab it if it slips. Just in my yard, no tall grass.

Clutch bell doesn't seem blue to me, this one literally has probably 10 minutes run time on it. Checked basic depth and ID dimensions to the stock one and seems the same.
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Old 09-25-2017, 06:05 PM
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So does the drive train feel smooth, meaning does it roll with little effort?? How are the clutch bell bearings???
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Old 09-26-2017, 12:05 PM
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The clutch shoes and clutchbell look normal to me. If the clutch is slipping against the bell, it's going to overheat it and turn it blue/purple. If the outside of the bell is all the same color as it was when brand new, I doubt the clutch is slipping when it's engaged - especially if using 1.0mm or even 1.1mm springs.

There doesn't appear any mention of clutchbell shimming. Sometimes the clutchbell can rub on the clutch shoe pins if they run proud of the clutch shoes. The pictures do not show this to be the case, so I'm not sure how there could be sparks coming from the clutch/bell. I would install the clutchbell and see how much lateral play you have. I'd also push on the clutchbell against the engine while turning to see if there is any binding.
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Old 09-27-2017, 11:36 AM
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I would be looking at your slipper clutch or transmission. I watched the videos you linked to via PM and I don't think the clutch on the engine is at fault, but rather the slipper clutch or something else in the transmission is slipping. If the main clutch was slipping that bad, the clutchbell would be blue and the clutch shoes would look a whole lot worse than they do.
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Old 09-27-2017, 12:03 PM
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Originally Posted by SlowLST2 View Post
I would be looking at your slipper clutch or transmission. I watched the videos you linked to via PM and I don't think the clutch on the engine is at fault, but rather the slipper clutch or something else in the transmission is slipping. If the main clutch was slipping that bad, the clutchbell would be blue and the clutch shoes would look a whole lot worse than they do.
Thank you very much, I appreciate you looking at that for me. Will do. Looking at the trans gears through the access hole I can't see anything. But what you are saying makes sense. I think on my savage I have to pull a ton of stuff off (the side plates) to get the trans out, but sounds worth doing.
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Old 09-27-2017, 08:53 PM
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Originally Posted by Gsmith1979 View Post
Thank you very much, I appreciate you looking at that for me. Will do. Looking at the trans gears through the access hole I can't see anything. But what you are saying makes sense. I think on my savage I have to pull a ton of stuff off (the side plates) to get the trans out, but sounds worth doing.
Exactly the main reason I refused to buy a savage and got LSTs instead. Savages are a headache to work on.
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Old 09-28-2017, 03:33 AM
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I think I figured it out, the steel spur gear after looking at it closer is in rough shape, it's wore way down on one edge, rolls ok by hand, but I pulled trans out and everything looked clean inside, put the last plastic spur gear I have in it and I think it's good now.

Can you still buy lst MT parts? I'm having fun getting back into this, but cant find any parts for the discontinued savage, and I really like playing with nitro vs going electric. Maybe time to find something else, I don't want to totally give up on nitro as the big red engine I just bought has less than a gallon through it
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Old 09-28-2017, 05:26 AM
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Originally Posted by Gsmith1979 View Post
I think I figured it out, the steel spur gear after looking at it closer is in rough shape, it's wore way down on one edge, rolls ok by hand, but I pulled trans out and everything looked clean inside, put the last plastic spur gear I have in it and I think it's good now.

Can you still buy lst MT parts? I'm having fun getting back into this, but cant find any parts for the discontinued savage, and I really like playing with nitro vs going electric. Maybe time to find something else, I don't want to totally give up on nitro as the big red engine I just bought has less than a gallon through it
Get a truggy and slap some MT tires on it. You'll wonder why you didn't do it a long time ago! I love nitro, electric is cool too, but nitro is just more fun for some reason! Having the ability to use a starter box to start the engine beats the hell out of pull starts and drill starts. Not to mention it really opens up your nitro engine selection because your not limited to pull start/drill start only engines.
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Old 09-28-2017, 06:26 AM
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Many LST parts are still available. My Hobby shop stocks Losi parts, but only a select few parts are discontinued (only because the Gas model kinda flopped because the gas engine was a piece of junk). I'd drop a savage for an LST any day. LST2 is my favorite, but an XXL would be cool too. Maybe someday after I have a buggy or truggy.
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