GP 10 / CR125 Engine / Seat Clearance

Todd Kageals · Joined: 15 Jun 2012 Posts: 271

My motor mount FINALLY arrive and I test fit it tonight. With the engine ALL THE WAY BACK against the stop, the left front corner of the motor still hits the seat (barely). If I slide it to where the paint marks show the engine was positioned before, it pressed hard into the seat. The side to side position of the seat seems to be set by the rather strong struts which are welded to the chassis (not the removable ones....those I could bend) so what do I do about this? Does anyone have seat positioning measurements for a GP10? The adjustment in the mount (a washer that can go on either side) has the engine in the "out" position so there's no more adjustment there. On another note....why don't they put a little more room in there? There's plenty of space between the side pods and another inch or two of elbow room would be greatly appreciated!

Ken Schilling · Joined: 01 Dec 2005 Posts: 1338

Last year I had a GP-10 with a large Ribtect seat with a Spec Honda that I raced with SKUSA in the S4 class.

Please remember that kart chassis aren't necessarily designed for a Spec Honda so fitment will sometimes necessitate a little bit of fiddling to get it to fit right.

You didn't mention your seat size, sometimes large or larger seats can cause interference.

Here's some starting dimensions for your seat placement:
- Bottom of seat flush with the bottom of the frame rails or slightly below but no more than 3/8".
- With caster in neutral position (if using Sniper pills): top center of left kingpin bolt to top center of seat = 105 - 107 cm.
- With axle in the highest position (low ride height): top center of seat to top of 50mm axle = 17 - 19 cm.
- The seat needs to have a little bit of angle pointing slightly to drivers right.
- You want to shoot for ~57% rear weight bias.

You do not want to use washers/spacers to move the seat side to side (to weak IMO). Use an old axle, preferable a stiff one, to very slowly bend the chassis seat struts to the drivers left. The drivers left one is easier to bend. Bend the tab areas of the struts to be parallel to the seat. Use 1-1/2" dia fender washers between the seat and the struts. The seat should just slip into place with very little to no pre-load on the seat struts. Lastly, if needed, if you have a fiberglass Tillet style seat, you can trim the "rolled" edge of the seat for even more clearance.

The picture below shows my 10" x 16" radiator.

Google "kart seat installation video" for a number of helpful tutorials.

I hope this helps.

_________________
Ken Schilling
#21x / S4 / ProKart Challenge (PKC)
SKUSA Data Administrator

Good luck is where preparation and opportunity meet!!!

The opinions I express are mine alone and do not reflect those of any organization of which I am a member.

marc-andre hubert · Joined: 10 Apr 2012 Posts: 174

i had to cut some of the my xxl full padded seat to clear top of motor above stator, no big deal everything clears now

Todd Kageals · Joined: 15 Jun 2012 Posts: 271

Ken,

That does help....quite a bit actually. Are you saying to stick the axle (or whatever I come up with) through the triangle shaped strut with the other end against the frame and then just lever it over? Sounds easy......well.....sort of.

Todd Kageals · Joined: 15 Jun 2012 Posts: 271

We need a US company to build us a spec. shifter chassis for the stock Honda. They could customize fitment and sell it cheaper due to the high volume they would have if we all ran it! I know....I'm new at this so I shouldn't make waves.....Wouldn't it be nice to have a chassis specifically setup for that package? If the rules required everyone to run it, they could build in more space for your elbows! Spec radiator, spec. brakes, built in the U.S., could be way cheaper .......sounds like a good idea......oh never mind.....that would make things way too easy!

Jeb Woods · Posted: Sat Jan 05, 2013 9:17 am Post subject:

I also have a GP 10, and got a motor mount that allows you to slide the engine out toward the side pod, it gave me much more elbow and seat clearance even with a XL Ribtect... Swedetech or Shark Shifter have them.

Jeb Woods · Posted: Sat Jan 05, 2013 9:23 am Post subject:

I forgot to mention, the offset mount does not allow you to access your oil drain plug because it over the frame rail. But still worth the hassle!!

Jon Romenesko · Posted: Sat Jan 05, 2013 1:59 pm Post subject:

Todd Kageals · Joined: 15 Jun 2012 Posts: 271

Jeb Woods · Posted: Sun Jan 06, 2013 11:17 am Post subject:

Todd, you may have that option with your mount already. inspect the mounting plate to see if there are other bolt patterns that allow you to shift the motor to the right. Mine came with a engine package from Shark Shifter, then finding out it had that capability during assembly..

joseph hollinger · Posted: Sun Jan 06, 2013 12:27 pm Post subject:

Pretty sure he already said that he had the mount in the right (outward) configuration.

Todd, it would be helpful if you would post some pictures of your problem. I'm running the same chassis, seat and mount and I'm not seeing the issue.
_________________
A lie gets halfway around the world before the truth has a chance to get its pants on. -- Winston Churchill.

Todd Kageals · Joined: 15 Jun 2012 Posts: 271

Jimmy McNeil · Posted: Sun Jan 06, 2013 8:41 pm Post subject:

The mount isnt the problem, it gets the engine about as far to the right as it can go, any further and the rear sprocket will hit the middle cassette hanger.

I wouldnt bend the right side seat mount, if you need to move the seat to the left, use a spacer.

Dont know how large your seat is but you may be able to twist it in the chassis a bit to get it to clear or you could simply trim the right side lip of the seat like Jon suggested.

If you have a large seat, you prob want it as far to the right as possible. If you move it to far to the left it messes up the angle of your seat struts.

Todd Kageals · Joined: 15 Jun 2012 Posts: 271

Well....I think my seat might be a size "7". I think it is Tillet's "Large". The more I have looked it over, I think I will try trimming that lip on the seat before I go trying to bend things. The seat doe fit snuggly in the struts as they are currently. I'm going to verify its position based on the numbers provided above and then trim it up. I'd buy a different mount but I am worried about moving the engine too far out and the affect it might have on the handling (and you are correct.....much further out and the rear sprocket would interfere with the bearings....it's already close). Now....my next question.....what's a good tool to use to cut the seat? A dremel with a reinforced cut off wheel? Hacksaw? I have never tried to cut fiberglass before so any tips would be appreciated.

Thanks,

Todd

joseph hollinger · Posted: Mon Jan 07, 2013 9:25 am Post subject:

Todd, there's a pretty good chance that your seat is mounted wrong. Like I said before, you really should post some pictures.
_________________
A lie gets halfway around the world before the truth has a chance to get its pants on. -- Winston Churchill.