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-   -   starting pin / pressure spring install (https://www.rcuniverse.com/forum/hpi-monster-truck-forum-250/7432411-starting-pin-pressure-spring-install.html)

newpat 04-28-2008 07:04 PM

starting pin / pressure spring install
 
Hi,
does anyone have a trick to install the starting pin and pressure spring back on? i just cant put the spring in AND hold the pin in place so that i can fit the starting shaft and backplate back on...

i should have thought about it before removing that :)

thanks,

twomanytoys 04-28-2008 07:08 PM

RE: starting pin / pressure spring install
 
Use a little grease to hold the pin in and just install the plate.

newpat 04-28-2008 07:09 PM

RE: starting pin / pressure spring install
 
will try, right now!!!!
i'll let u know!

thanks,

newpat 04-28-2008 07:29 PM

RE: starting pin / pressure spring install
 
ok, get this thing in... before i put it back together and smoke my engine, here is what i get now...

if i turn the flywheel, the starting shaft doesnt move (good, right?)
if i turn the starting shaft one way, the piston moves, not if i turn it the other way (good, right?)
when i turn the starting shaft so that the piston doesnt move, i can hear a little "click" at each turn, obviously when the pin jumps back into the groove... that should be good enough to start my engine safely?

thanks for your help again,

drivefastgto 04-28-2008 07:53 PM

RE: starting pin / pressure spring install
 
Sounds right!

newpat 04-28-2008 08:08 PM

RE: starting pin / pressure spring install
 
well, thanks for your optimism, but it wasn't right :) i screwed the plate on, moved the starting shaft back and forth as it is supposed to behave when the engine runs... the more i moved it, the harder it was... i took it all apart again because i didnt trust it, and sure enough, for some reason, the pin is gone, the spring is f***ed...

another day wasted, another $5, and another trip to the LHS (where, btw, they are great to get you to spend $600 the first day but then the customer service gets from bad to worse no matter how much you spend there... but that's another story...)

it's painful to be a newb... [:@]

NitroVenom 04-28-2008 08:25 PM

RE: starting pin / pressure spring install
 
My bro has a savage and I still have no idea what your talking about... Can you give me a link or something to show me what it looks like?

newpat 04-28-2008 08:42 PM

RE: starting pin / pressure spring install
 
mhm,
i'm talking about the starting pin # HPI 1433. trying to make it simple, it's a small pin at the bottom of the piston "leg" (as i still dont know the proper name). when you crank the roto start / pull start, it turns a shaft called the starting shaft. this one's got a plate at the end of it, with a groove on that plate. the starting pin fits in that groove.
so: rotostart turns => starting shaft turns + grab the starting pin => piston starts moving => engine starts
when the engine runs however, the shaft is not supposed to spin... thus ONE-WAY BEARING...
sorry i cant explain any better, and right now i cant find an exploded view of the engine...
once your bro smokes his OWB and goes one step too far into removing the backplates, you'll know what i mean :D

carldav 04-28-2008 10:22 PM

RE: starting pin / pressure spring install
 
1 Attachment(s)
Are you pertaining on this? Is the pin you were asking? After doing my usual rebuild this spin was removed from the one-way housing.

newpat 04-28-2008 10:25 PM

RE: starting pin / pressure spring install
 
yep, however the plate on the left doesnt look quite the same as mine... i started another thread on that, i was wondering if somehow i could get rid of the spring + pin assembly, or at least the spring :)
could that be the solution ?? :D
thanks!

drivefastgto 04-28-2008 10:30 PM

RE: starting pin / pressure spring install
 
It shouldn't be this hard...I've removed my backplate several times (on two different F4.6 motors) and have installed the pin/spring without any trouble. Are you tilting the front of the motor down? That helps the pin stand up in the hole until you lower the shaft/backplate onto the crankcase. I also push the pin/spring as far as I can in the hole, and SLOWLY release the pressure on the spring so it doesn't fly out.

newpat 04-28-2008 10:39 PM

RE: starting pin / pressure spring install
 
yeah, i tried that, also used some grease to hold the whole thing together...i think what happend is that the spring and pin somehow moved a little tiny bit and didnt perfectly line up when i screw the backplate on... newb mistake i guess... i'm just pissed off that i have to go back to the LHS, deal with those guys again and potentially screw up another spring [>:]

thanks for your support :D

drivefastgto 04-28-2008 10:44 PM

RE: starting pin / pressure spring install
 
Hmmm, are you trying to line up the groove on the starting shaft with the pin too? That could possibly let the pin slip out before the backplate is all the way on. I forgot to mention it, but I always try to put the pin against the flat part of the shaft, so it's pushing against the spring before it's fully installed. Does that make sense? :D

newpat 04-28-2008 10:48 PM

RE: starting pin / pressure spring install
 
it does... i was actually trying to line it up with the groovy groove on the starting shaft...[:@] so yeah, if you apply pressure on a spring and it has a way to escape and release the pressure, sure enough it will go this way...learn through your mistakes, i guess...
i'll try again tomorrow if the LHS has another one in stock...

thanks!!!

-SomeGuy- 04-28-2008 11:27 PM

RE: starting pin / pressure spring install
 
Can you take some pics of the hole the pin goes into? It shouldnt be coming out while its all together, lets just see if everything is ok before you go spend more money.

newpat 04-29-2008 06:23 AM

RE: starting pin / pressure spring install
 
there will be no pics for now as i'm heading back to work. but to give you an idea, the spring itself goes only half way in this hole. from what you're saying i imagine the spring should go way further than this and the pin should go half way inside the hole at least, right?
maybe i didnt push the spring far enough at first...
if you look at the 2nd pic from carldav above, the way he's got the pin coming out of the hole is how my SPRING looks when i put it in...
Carldav: is the spring in place on this pic?
if so this is my problem...

thank you guys!

carldav 04-29-2008 06:46 PM

RE: starting pin / pressure spring install
 
1 Attachment(s)
Good Day

I just found out that you were referring to the spring of a 21BB Engine. The one that I posted was from a K4.6 where the pin and one-way bearing was made in a single piece without the need for springs (part number 15233)

In my case, I think it was pretty worn out and as a result the pin went lose so I have to replace it with new one. Kinda sucks though since the one-way bearing is still functional :(

newpat 04-29-2008 07:01 PM

RE: starting pin / pressure spring install
 
hi,
i was actually referring to the 4.6 that comes with the X 4.6 RTR (roto start). i guess i should have mentionned that in my first post and in any new post...
but you get me quite interested in this :) does this pin+OWB single piece work with a rotostart, or do i have to upgrade to a pull start?
i know i'm not gonna change this spring & pin every second day, but i'd still like to know for the next time it happens!!

that's exactly what i was looking for after i got pissed off last night :D

thanks a lot!

carldav 04-29-2008 08:18 PM

RE: starting pin / pressure spring install
 
1 Attachment(s)
That I'm not sure if it works with a rotostart... by the way those parts that I posted is from K4.6 (pull-start set-up) from my Savage X SS.

Since the one-way in my previous pic is still working, I'm thinking of using a threaded pin (part number 86094) so that it will not fall-off or loosen. What do you think?


newpat 04-29-2008 08:24 PM

RE: starting pin / pressure spring install
 
well, if you can somehow thread the hole in which the pin sits so that the threaded pin fits and holds, i dont see why not... keep it the same length as the pin, just to make sure...
are these the same diameter or real close?
if i get you right, the thread on the threaded pin should actually be slightly larger than the starting pin, right?

i dont have the tools to do that but if you do it's probably worth trying!

let me know!

carldav 04-29-2008 08:34 PM

RE: starting pin / pressure spring install
 
Yup, will do that. I have a machinist friend who can fabricate steel and aluminum parts. He already fabricated some parts for my savage already like wing mounts, tank guards, steering posts, etc.

Will just have to get the measurements of the pin that went off and drill a threaded hole. I also intend to use a red locktite or have it weld. I will see how it goes...

Thanks
Carl

newpat 04-29-2008 08:37 PM

RE: starting pin / pressure spring install
 
you should be OK! i wish i had a friend like that, i'm dreaming of a custom made roll cage !!! i just cant find one that works for me [:o]

good luck with that, you'll make it work!

Pat

newpat 04-29-2008 08:58 PM

RE: starting pin / pressure spring install
 
1 Attachment(s)
could some of guys check these pics and tell me if that's how the spring is supposed to look like before i put the pin in?
i just can see it happening: if i put the pin in and it doesnt exactly perfectly line up with the spring, it's not gonna go down inside the hole and i'll get screwed again :)

thanks!

mazdab2600 04-29-2008 09:15 PM

RE: starting pin / pressure spring install
 
here's pic of the f4.1(.25) same basic's as the f4.6(.28).
the pin just sitting on the spring should look the same as the pic.
http://i5.photobucket.com/albums/y20...rterpin001.jpg

newpat 04-29-2008 09:18 PM

RE: starting pin / pressure spring install
 
that's what i thought, otherwise it's nearly impossible to get it straight down the hole... mhm, maybe i've got some pieces of the old spring left in the hole, or otherwise i dont know why it wont go down just like yours...
at least now i know what it should look like before i put the backplate back on!

thanks a lot for the pic!! :D


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