Home Forums Shifter Karts crank seal installation?

This topic contains 28 replies, has 9 voices, and was last updated by  Broque Ward 1 year, 2 months ago.

Viewing 25 posts - 1 through 25 (of 29 total)
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  • #4276

    nigel cooper
    Participant

    Which way is the best way (and why) to install the crank seals on a CR125.After the crank and halves are assembled or before the crank is installed? Both ways are possible but I wanted to know from the experts which is bes tand why.Thanks!

    #4279

    Tyson Henry
    Participant

    I really don’t think it matters. Just make sure they aren’t pressed too far in.

    #4374

    Broque Ward
    Participant

    Its easier to press them in without cranks, tranny shafts etc in the way.. U can either use a seal.pressing tool or a socket that is the same.circumference as the seal

    #4541

    Frank Rapisarda
    Participant

    Nigel crank seals should always put in after the cases have been put back together. small rubber hammer and socket or a 3/4″ punch. You should be able to press them half way in with your fingers.

    #4552

    Chris Reinhardt
    Participant

    I always install the seals after the cases are assembled.  I fabricated a “tool” just for the job.    Basically it’s a hunk of tubing that fits over the crank, and a large washer that lays on the seal.  On the primary side use a bolt that threads into the crank end to draw the seal in, and on the stator side, use the nut on the crank to pull it in.  Works perfect, pulls them in nice and straight every time.

    CR

    #4573

    Andrew Pachon
    Participant

    Chris, would you be so kind as to post a few photos of this fab’d tool?

    ~A

    #4628

    nigel cooper
    Participant

    Thats  a great idea on the tool Chris!  I`m going to make  them out of  scrap emt tubing and various washers. This is much more “controlled” than my previous tapping with a hammer and socket.  Thanks for sharing.Any more home made tool ideas for 125 and 250 engines?

     

    nc

    #4647

    Chris Reinhardt
    Participant

    Chris, would you be so kind as to post a few photos of this fab’d tool?

    Dude, it’s a hunk of tubing and a washer, use your imagination!!!

    CR

    #4688

    Tyson Henry
    Participant

    Some people really like to over  think simple tasks…..
    Jesus guys, its a seal that needs to by put in reasonably straight.  It is extremely easy to do with a socket and hammer with light taps.

    #4690

    Chris Reinhardt
    Participant

    A hunk of tubing and a washer, real complicated!!!!  You can’t “over think” a motor build, that’s how you improve it…. You’ll find out that the straighter the seal is, the better it will seal, the less it will drag, and the longer it will last….

    I know, it’s not measurable, but that’s how you blue print a motor, all those little things add up….

    CR

    #4694

    Tyson Henry
    Participant

    Gonna bust out the dial indicator on it to make sure it is perfect?

    Look, I’m not saying it’s a bad idea. I just can’t imagine why anyone can’t get it basically perfect with a socket.

    #4695

    Chris Reinhardt
    Participant

    Dude, whatever,  but smacking a seal with a socket and a hammer isn’t the right way to install one in any application, just shade tree mechanics 101.

     

    CR

    #4830

    Sam Zavaglia
    Participant

    Since this is about Crank Seal installation for CR125, the cranks are not slip fit from OEM into the bearings and the bearings are not slip fit into the cases. Therefore something needs to be heated up to assemble the cases shut and you wouldn’t want heating being done while new crank seals are in place, so the crank seals go in after the cases are closed.

    What this also allows is the check the crank spins freely with cases torqued up which otherwise could not be felt if the seals are in there creating some resistance.

    I like the idea that Chris R has for crank seal installation, while it may be a little overboard for someone who does this job once every 2 years, it’s certainly a effective tool and nice way to do it if your doing this on a regular basis. The last thing you would want is a seal popping out on the transmission side to suck in oil into the crankcase at a race meeting. Maybe even recommend some loctite sealing compound between the seal and cases even though I’ve never used a sealing compound on CR125 or personally had a crank seal pop out of any of my CR125 rebuilds, however free insurance if you have some laying around.

    Ohhh and some advise that I’ve always taken from a reputable engine builder, always lube the inside of the crank seals that makes contact with the crank shaft with some Moly grease. Slips though nice to avoid damaging the lip and creates great sealing while bedding in. ;-)

    #4915

    Greg Wright
    Participant

    The Honda crankcase assembly tool will install the seals after the cases are bolted together.

    #4990

    Chris Reinhardt
    Participant

    You still have to use a washer under, otherwise it’s trial and error,  and you risk damaging the seal

    #5010

    Greg Wright
    Participant

    You still have to use a washer under, otherwise it’s trial and error, and you risk damaging the seal

     

    Uh Huh, Yeah of course. I didn’t feel I needed to state the obvious.

    #5387

    Broque Ward
    Participant

    um correct me if im wrong but doesnt the tranny side crank case halve lift off the crank? the stator side of the crank is pressed in…  not sure why you guys are heating the cases to press a crank in? ive done numerous cases for cr motors and a press does fine with no heat.

    a seal tool kit will press int he seal nice and even without the crank in place.. why would you complicate such a simple installation? I understand about seal alignment and do so with the seal tool kit and mic it after???

    #5403

    Chris Reinhardt
    Participant

    um correct me if im wrong but doesnt the tranny side crank case halve lift off the crank? the stator side of the crank is pressed in… not sure why you guys are heating the cases to press a crank in? ive done numerous cases for cr motors and a press does fine with no heat. a seal tool kit will press int he seal nice and even without the crank in place.. why would you complicate such a simple installation? I understand about seal alignment and do so with the seal tool kit and mic it after???

     

    Broke, I have no idea what you just said!!!!  Neither side slips in from the factory if that’s what you were referring to….

    How does your seal instal tool work with the crank installed?  I can pop almost any Honda seal in with my thumb if there’s no shaft in place, straight as an arrow, no worries.  The issue is when the shaft is in place.

    Necessity being the mother of all invention,  I had a bad stator side crank seal that I needed to install with the crank in place at the track.  Pull the seat out, pop the stator wires out from the cutout in the case, pull the flywheel, carefully remove the old seal with a flat blade, install the new seal as I’ve described with the home made tool, done!  After seeing how easily it actually works, and how perfect the seal goes in without worrying, I do them all like that every time.

    People can do it this way, they can not do it this way, use a BFH and a rusty socket, whatever floats your boat….

    CR

    #5413

    Broque Ward
    Participant

    you never heard of a seal tool kit? who said anything about rusty sockets?

    no slip fit crank halves hmm? oook lol

     

    #5431

    Chris Reinhardt
    Participant

    you never heard of a seal tool kit? who said anything about rusty sockets? no slip fit crank halves hmm? oook lol

     

    Have a nice day Broke……

    #5741

    Broque Ward
    Participant

    listen chris my name is broque.. i bet you cant even pronounce it correctly and if i said it to you wihtout knowing the spelling I highly doubt you can spell it correctly. HA!

    I got some seals for you to press to chill that arrogance with.

    #5752

    Chris Reinhardt
    Participant

    Broque, is that Celtic for annoying?  :)

    CR

    #6266

    Sam Zavaglia
    Participant

    I did a full rebuild on the weekend for a friend, installed the seals AFTER the cases where closed up with some loctite with my thumbs and a piece of solid timber/lumber and my steel hammer…..tap tap tap tap.

    I wish I had that special tool to make it a bit easier but as people have said, its not rocket science and I only do this job on people’s CR125’s maybe 3 times a year.

    Bro, bearings/crank are not slip fit from factory, if it was meant to be slip fit don’t you think the factory would have done so? Same goes for CR250. People may prefer the slip fit mods for convenience.

    PS….Bro, does the pronunciation of your name sound similar to the 44th President of the United States?

    #6276

    Broque Ward
    Participant

    No its not barack its one syllable

    #6280

    Sam Zavaglia
    Participant

    Well since my first guess pronounced as “brark” is incorrect, I’m now guessing it’s pronounced as “brock”.

    Cheers

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