Trap door mod to access shift forks

[Carter Turk]

I'm wondering if anyone has done this mod to their bike with the engine still in the frame. I queried on the old school suzuki site about it. and saw a few pictures. I looks relatively straight forward.

I know CBX Chris mentioned this to me awhile back. I thinking about doing this after someone here mentioned that my clutch not engaging all the way might be a bent shift fork and not anything to do with my clutch.
Carter

[Hap Call]

I'm very interested in this...how is it done? Do you have a link? I'm about to pull my motor and split the case and it might be a mod I would want to do...



Hap

[Carter Turk]

Hap

Take a look at the oldskool suzuki site and go to info board and look for the aircooled catagory. I asked the same question there and there's a link with pictures. I'm still mastering the typewriter so I can't put the link here. Carter

[scotty]

I saw that mod a couple of years back but dont remember where. It was a scairy thing and i believe case braces were necessary after doing it. But it looke like a trickey job.

[Dink]

the best place to see the mod is www.bertaut.com/gsengine2.html it shows pics
as well as some instructions as to how and why.
Dink

[cbxchris]

Basically you remove the web bracing in the cases. That will give you just enough room for the forks to slide through the bottom case. I would only do the machine work with the engine apart. You can also mod the cases for shift shaft removal. I would only do this in a drag racing application.

[Anonymous]

... I would only do this in a drag racing application.

I think that is the key point that should be made.

[Dink]

... I would only do this in a drag racing application.

I think that is the key point that should be made.

I agree.
Dink

[Carter Turk]

About only in a drag race application. Seems like more stresses would be occuring on the strip than on the street. Drag racers keep using the same cases, dont they? So why is this such a critical point. Carter

[Dink]

Drag racers do it a s a trade off, they a far more likely to bend a shift fork etc than a street riden bike ever is. they NEED the ability to change a shift fork without splitting the cases, they have 30 minutes to an hour to fix it in, a street bike is not effected in this way.
It is obvious that this mod would in some way effect strength in the cases so that is the trade off. That is also why I believe it is unnecessary on a street bike.
Dink

[Hap Call]

I came across an engine that actually has this capability when stock. It was a CZ 250 dirt bike and the trap door was on top behind the cylinder...pretty cool.

Hap

[Carter Turk]

I'm pressing this point because it seems like a lot of work, time and money to split the cases just to change a shift fork. I'd really hate to do this for that reason.

Is there any chance that the shift drum spring that I think attaches to the internal webbing be an issue with my clutch? That would be nice since I can access through the oil pan.

And what about the shift shaft mod. That seems like less of a trade off than the trap door. You could attach a small plate similar to the three philp head below but smaller. Carter

[Hap Call]

Carter, I'm about to split the cases on my 1100 without dismantleing the top end. I need to replace the backcut gears because I'm having problems downshifting. I think it should take me a weekend to pull the engine, split the case, replace the gears and put it all back together.

Hap

[Carter Turk]

Hap,

Yeah, you're the man. I have to really pyche myself up to open up the engine. I've split four motors, but there's always that nagging feeling when torqueing the bolts back to spec. You're waiting for the click, you know it should be coming but it isn't there.

I snapped one of those long 6mm bolts underneath the cam chain tensioner on the top case half after carefully sealing the case halfs and getting all the C-rings in place and torqueing the bottom half to spec Had to tear it all back down again to get a that bolt. Frustrating.

Now I need to get motivated to check my valves. Carter