gsxr400 and gsf400 engine/frame interchangability

[El Dopa]

I have a couple of questions about gsxr400 and gsf400 engine/frame interchangability, specifically in relation to the gk75 engines.

My understanding is that the gk75 engine used in both the gsxr400 and the gsf400 is the same basic engine. However, the cams and carbs are different, with the gsxr400 having a different, bigger, head to fit the gsxr400 cams, which have a more aggresive profile.

1) Is this correct?

2) Is anything else different?

3) Assuming this is correct, what needs to be done to change the bandit cams for the gsxr400 cams (e.g. for a gk75 motor)? Is it a relatively straight swap? Assuming you have the parts, do you just swap the heads over?

4) If the cams are swapped over, are there any issues with 'room'? That is, will the gsf400 engine, with the new head in place, bolt straight back into the frame, clear the tank ok, etc (i'm not worried about the airbox as this will be binned and replaced with pods).

5) What are the differences between the gsxr400 carbs and the gsf400 carbs? Is it just needles/jets?

I'm asking because I've been offered a gsf400 as a 'parts bike' cheap. I'm toying with the idea of rebuilding the motor/carbs/airbox specifically for use as a track toy.

Rebuild the carbs with a race kit, swap the cams/heads, and possibly bore it out.

Bolt it all back in, et voila!

[Banditmax]

GSXR cams fit straight into the GSF head no problems. The only difference is the cams themselves. OH and the gearbox ratios. CArbs in the USA i think the us spec are 32mm the GSXR ones are 33mm

[gsxr400 racer]

you can take a bandit motor put the oil pan from the gk73a on and throw it right into a gsxr frame your carbs would be fine gk73a 1989 sp had 33mm 88 model had 32 just like b4 some b4's came with 33's run two intake cams and dont worry about the gsxr cams , leave the b4 oil pan on and run your exhuast another option

[El Dopa]

you can take a bandit motor put the oil pan from the gk73a on and throw it right into a gsxr frame your carbs would be fine gk73a 1989 sp had 33mm 88 model had 32 just like b4 some b4's came with 33's run two intake cams and dont worry about the gsxr cams , leave the b4 oil pan on and run your exhuast another option

Well, I'll be swapping a (modified) bandit motor into a bandit frame. What I was worried about was any changes to the head that would affect clearance. But if the gsxr cams drop straight in, that shouldn't be a problem.

You're suggesting don't worry about the gsxr cams as a mod. Why not, if they drop straight in?

I have a really good yosh header already. I also have a pair of good carbon pipes that i'm working on mounting. Now all I need is a 1-2 link pipe....

[gsxr400 racer]

[quote="El Dopa]
Well, I'll be swapping a (modified) bandit motor into a bandit frame. What I was worried about was any changes to the head that would affect clearance. But if the gsxr cams drop straight in, that shouldn't be a problem.
heads are the same just different color

You're suggesting don't worry about the gsxr cams as a mod. Why not, if they drop straight in? They are only different if you have a 1993 model which is de tuned if in the past i have told people different im sorry.
I have a really good yosh header already. I also have a pair of good carbon pipes that i'm working on mounting. Now all I need is a 1-2 link pipe....[/quote]

Hope that clears it up for you
cheers
jay

[revhard05]

i have a 93 model can i still do the gsxr cam mod????

[gsxr400 racer]

a 91-92 b4 cam would be fine but i think banditmax was doing this to his as he has a 93 yours has 3 wires to the small plug on the cdi? if so see if your bike feels like it pulls harder in 4th than 5th and 6th if it does this talk to him he has a derestrictor he would prolly sell you