[i3notsr]

Dropped the frame off at the shop yesterday to get the motor put back in. One step closer to being finished. Found out that no...there is not a full system for the kat being made (no surprise there) so the stubby exhaust will be used for now and if things are not where I want them I will get the delkevic system it looks like. Hoping the bike is all together by the end of the week. Just need to take them the egr stuff or figure out what block off plates will work...

[shpielers]

Block off plates are super easy to make yourself if you have either a dremel or a grinder. If you don't have the old connections that were on there, just get your plate big enough to bolt on and cover the opening. 2"x.75" should do it. Make sure you use a high temp oil/gas resistant gasket that you cut to the shape if the plate.

[i3notsr]

The motor is in...YAY!!! New tires are on as well as the sprockets and rear rotor. Hopefully it will be all done by next week.

[shpielers]

If the pistons were gone and needed to be replaced then I was going to do just that. However, for the time being it looks like the bike will remain a 750. I plan on bumping the displacement up to around 1200 on the next rebuild, along with larger valves and stepping up the cam size. I figure this new motor should last me a couple years with any luck. The guys working on it at the shop seem genuinely excited about the work being done. The head work was not bad...just shy of 2k. Overall i'll be coming in under what it would cost for a new bike, at the moment I am roughly at 5k into the project.

Just now saw the part about bumping it up to 1200cc - you realize that requires a different engine altogether yeah? 750s can't be bored out that much. An 1127 from a 1100 Kat or GSXR can, and the 1157 from the Bandit 1200 can though. I think as high as 1240cc before it start becoming a problem, but It's late and I might be misremembering the max size.

Or am I just reading that all wrong and you're going just aquire an engine that's already around 1200cc and start modding from there?

Also, for exhaust systems, I believe holeshot makes a compete system.

[i3notsr]

Lol, I actually have no clue what the max increase in displacement would be. I thought that it would be possible to jump up to around there, but I suppose not. Thanks for heads up.

[shpielers]

If you want to get really crazy, you can start doing stuff like head swapping. Ie an old oil cooled 750 GSXR head/cylinders onto your 600 bottom end. After over boring it to 771 or higher of course

There's a bunch of old threads that cover this type of stuff. Years that are compatible for swaps such as this, max bore size, problems you'll encounter etc.

This one talks about straight engine swaps.

http://katriders.com/vb/showthread.php?t=107365

This is about mix and match/plug and play. You'll probably like this more:

http://katriders.com/wiki/index.php5?title=Engine_Cross_Reference

[i3notsr]

I'm not sure but I think that last one was meant for another thread...?

[shpielers]

Nah, just throwing some info your way. Figured if you're actually willing to get a head worked on and thinking of boring cylinders that this stuff might be of interest as well. There's lots more engine mod info around here that's probably more up your alley. I recommend the google search! (Normal site search is a bit on the weak side)

[i3notsr]

Cool, I got thrown off by the 600 and using 750 head and cylinders cause I have a 750 lol. These motors are crazy with what they took from what to make them. After getting the head back from getting ported they were saying that once they got inside the head it looked closer to an 1100 head than a 750. I'm still new to messing with motorcycle motors so thank you for the tip, I will defiantly look that stuff up.

[i3notsr]

Status update...the engine runs. That's about it. The electrical is getting started while they wait for jets to do the carbs. No, I have not heard the engine turn over as I don't want to spoil the finished product. Maybe 2 weeks left, I hope lol.

[i3notsr]

just another quick update, the only thing left to be done on the bike is to clean up the wiring and hook up the lights and hand controls. The m-unit and m-lock are installed and the bike starts using the hand controls. The end is near, if it gets finished by this weekend I will post a walk around video along with the first ride in 5 years.

[i3notsr]

On a side note that I thought was pretty interesting as I don't really "know" carbs. They said that they needed to order main pilot jets 2 sizes larger than stock to get it to idle right. As I have no actual clue what that entails, what does that mean? Like is it compatible to a stage 2 or 3 jet kit ( if they made one for this bike...)? I can't really say I gave in but they started the bike for me, there was a noticible lope at idle compared to how I remember it and about 2000ish rpm sounded very meaty.

[shpielers]

Well you had head work done, so that'll change the airflow. I'm not surprised rejetting is required. No idea how much you'd have to expect, but I'm sure you'll want some sort of jet kit.

[i3notsr]

I know that the carbs need to be jetted, and from what I understand that is what they have done. What I am unclear on is the level of jetting done, I guess is what I am getting at. I was thinking around a stage 3 jet kit for a J motor gsxr would be needed, and that's what I was thinking just based on the head work. Add in the cams and now i'm lost. I don't even know how much of a step up the cams are lol, because I don't know what the stock cams lift and duration are. All I know for sure is that the tech working on the bike made the step up in pilot size seem blinking crazy and severe.

*EDIT* Ha I just found the lift and duration...well not for the kat but for the 86-90 gsxr-750. From what it looks like I threw in cams with a tad more bite than the Yoshi stage 2 cams...at least I now have a base for the cams.

[shpielers]

I'm not an expert on this, but I believe since you changed a few things a whooooole bunch, there's not really going to be much in the way of baseline. Other members have built motors in the past, but so far as I know, Arsenic is the only regularly posting member anymore to have done so. I know with some of the jetkits stage 3 means running pods - you still have the stock CV Kat carbs. I'm under the impression that the normal back pressure issues with the Kat carbs/pods would still be there. Stage 1 might be more appropriate. But like I said, I'm no expert on this. So if this is wrong and someone who knows better reads it, please drop some knowledge!