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Pull start not always "catching"

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bobthebob

bobthebob

RCTalk Racer
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Location
Hillsboro OR
RC Driving Style
  1. Bashing
Hello wondering if someone can help diagnose something for me. I'm starting to have a problem with the pullstart on my k4.6 in my Savage X SS. Sometimes it doesn't seem to "catch" the engine, like I pull and it just pulls freely without moving the engine. If I pull at an angle towards the front of the truck, it pretty much always works but if I pull straight out it seems to be missing the crankshaft. Does this sound like the one way bearing, or the pull starter itself? I hope its the pull starter because I already bought a spare.
 
Probably the OWB. Do you user after run oil? Do you let it sit quite a while between runs?


If it sat a while between runs (more than a few weeks), it could just be gunked up and the needle bearings aren't freely moving around in the cage. A cleaning will help that out.

Looks like that engine has an internal OWB, so you can take it apart, soak it in DA and spin it on a tightly twisted DA soaked paper towel to work any gunk build up out of it. Make sure to spin the bearing in both directions to work the varnish/gunk out of it. Make sure to thoroughly clean the shaft it spins on as well. Then put a few drops of ARO on it and put it back together.

If you run it frequently and use ARO, then odds are, it's wearing out on you. If you do replace it, replace both the OWB and the shaft that spins it as both items wear, so replacing only one or the other only half helps your issue and tends to shorten the life of either new part due to the imperfect surfaces.
 
No after run oil, and have been running the engine pretty frequently. No more than a week between runs so far. I was trying to figure out what the OWB was and didn't see the part listed, so that makes sense that it is part of the engine. I guess I need to get some DA. I was wondering if that stuff would be good for cleaning old thread lock out of screws also. Regular iso alcohol or nitro fuel doesn't seem to do it.
 
I doubt it. That stuff gums up and short of a wire wheel or fire from a torch, it doesn't go anywhere. DA is just iso alcohol minus any water. Also smells awful.

I found your parts explosion on HPI's site so I could see what kind of bearing it used. Internal or external, they get sketchy over time due to wear. Internals tend to get more gummed up though since they get fuel on them all the time. Usually, if you can get the engine going and it warms up, the OWB is fine the rest of the day. But if after that it's still fussy, then odds are, it's worn or really gummed up.

http://www.hpiracing.com/assets/documents/instruction_manuals/i15201-k46-glb-m-v1.pdf
 
I agree with olds on this one for sure! One way bearings are finicky little suckers... They can be cleaned out a lot of the time. Then a LIGHT coat with some LIGHT grade motor oil like the mobile 1 you might put in your car and you're good to go again. You MAY have some loose parts in there where maybe the starter shaft may not be grabbing or it may be worn. Just be careful when you pull it apart that you don't shake anything loose in your pull start assembly or you'll find yourself winding up springs and cords etc... That's no fun! Also, be sure during reassembly that your cord knot is tucked away nicely so there is no friction when it goes to recoil. (if it's recoiling ok now, just don't mess with it and you'll be fine).
As always, curious to know how your repair goes and what you find. Let us know!
Good luck!!!

Brake clean or carb clean for a 1:1 car will likely clean up your bearing nicely... As far as removing the old thread lol, yeah, heat or a wire brush on a dremel or similar will prob pull it off too.

Jeez! My fat thumbs were hard at work sabotaging this post too!!! Sorry for the confused words. I hope I cleaned up so it makes sense. :D
 
Last edited:
Certified Mike said:
I agree with olds on this one for sure! One way bearings are finicky little suckers... They can be cleaned out a lot of the time. Then a LIGHT coat with some LIGHT grade motor oil like the mobile 1 you might put in your car and you're good to go again. You MAY have some loose parts in there where maybe the starter shaft may not be grabbing or it may be worn. Just be careful when you pull it apart that you don't shake anything loose in your pull start assembly or you'll find yourself winding up springs and cords etc... That's no fun! Also, be sure during reassembly that your cord knot is tucked away nicely so there is no friction when it goes to recoil. (if it's recoiling ok now, just don't mess with it and you'll be fine).
As always, curious to know how your repair goes and what you find. Let us know!
Good luck!!!

Brake clean or carb clean for a 1:1 car will likely clean up your bearing nicely... As far as removing the old thread lol, yeah, heat or a wire brush on a dremel or similar will prob pull it off too.

Jeez! My fat thumbs were hard at work sabotaging this post too!!! Sorry for the confused words. I hope I cleaned up so it makes sense. :D
Click to expand...

Thanks for all those tips! Been putting up with the pull start still for now but it's def getting worse. Was having a heck of a time priming it today and after my run noticed that the rubber tube connecting the header to the exhaust is loose and leaking air/oil, so that explains that. Seems like the zip ties have stretched over time. Ran a half a tank after finally get it primed until I crashed and caused another brake disc bind up. Sooo looks like it's time for a complete tear down now. Get OWB cleaned and perhaps replace pull start, replace my center gearbox housing because of the stripped brake hold-in screw, replace metal disks with fiberglass disks, and... and and...... if tower ever gets my reverse module in stock, install that too! Which means I basically need to stop driving the truck for a couple weeks in the hopes they really do get it in stock this month like they say. Definitely don't want to take the truck apart again a week later to install that.
 
Yup! Sounds like a tear down/rebuild! You'll be LOVING the truck again after that! Likely the zip ties got hit enough to stretch a bit. I'd just replace the whole thing again. Maybe look for the tie wraps that have the metal tongue that grabs. That type doesn't use teeth so when it pulls 'tight' it's not limited to a 'click' tighter or looser if you follow me??? (congrats if you do!!! :hehe:) Is prob look into upgrades brake assemblies at this point. Hop it up while you have it apart and you have found a 'known issue'! That is Def the forums answer to the famous question... :'( just bought a 'xyz' rc and I want to know what I should do to hop it up???!!! Of course, there will likely be an answer that says 'xyz's' ALWAYS need a kiniflin pin and a bucket of blue steam... But short of that, don't replace anything with hop up parts til something breaks... THEN upgrade... You get what I'm saying I'm sure...
I would DEF get the module and whatever else you want to do before I rebuilt... Do it once and do it right! Of course, that has also kept me from diving into a couple projects I have sitting with sad faces... Sitting on the shelfs collecting dust.
So def... Good luck with everything and Def post pics as you go... Of the damage and of the fixes!!! It's incentive to me and I'm sure to others here! :thumbs-up:
 
Id replace the O-way if that engine has the internal one ,they have the pin inside that are notorious
for wearing and breaking off.
I run a 5.9 that takes them an also some axial engines that do as well.
If the o-way is old & worn ,replace it ,you don't want the pin to snap an get sucked into
the piston/sleeve!
 
If you go look to buy one ,they are actually called pullstart shaft holder!....Lol

upload_2016-11-6_17-6-8.webp


I have a couple of them laying around were the pin just fell out!...:doh:
 
They are cheap. I would order it anyways. The savings on shopping the 2 together (if tower ships that way) would be worth the price alone. Aside from that, just to Have it ''in case" would be worth the $6 to me.
 

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