Question. Is there a horizontal version of this motor?

No. Largest horizontal block they make is a liquid cooled 821 cc. Fd851d I believe. 31 hp, fuel injected. Different design than the fx100v

The largest air cooled is a 28, 736cc I think. I believe it's the same block as the fd750d (liquid cooled 745cc), but I'm not sure if the cylinders are the exact same without the water jackets cut, or if there is less size there which eliminates the ability to bore it out very much. It's something I intend to look at as soon as my Briggs starts leaking at the case gasket.

Somebody needs to get a 28 and take that bitch apart

Correct. But it is a hemi

I put the stock cam back in mine yesterday. Gonna see what it will do with .050 heads and Mikuni.

I'd like to see all this on a data sheet of some sort or a chart showing what boats are being pushed with what speeds at what rpms and which mods they have been tested with .

I went back and read this whole thing yesterday haha. Mostly a waste of time, I stopped scrolling when I saw the kawi pro icon then start reading again

Yall keep saying there is a P2V clearance issue...if that were really an issue it would be an issue at idle...It would be an issue turning the motor over by hand... The intake valves are barely open with the piston at TDC. They should be well inside the chamber in the head. The problem is in the geometry. The guys touching off are falling off the valve stem and pinning the valve open. They are only touching off when they float the valves, and with that much lift and that little bitty valve stem, if you float even a cunt hair, you fall off the valve stem and the adjustment screw gets pinned down in between the keeper and retainer..

Shorter push rods should correct the issue, but I don't really like the steep angle you start at when you do this.. We're gonna see how it works though. Hopefully better than what was being recommended before..

What happens when you fall off the valve..

Valve closed with shorter push rod to accomodate high lift cam and decking.

Valve open with corrected push rod.

Before right at about .400 total lift, you would fall off the stem. With the .310 cam and rocker ratio, total lift is about 387.5, which doesnt leave much room for error. Slightest over-rev can cause a serious issue. This is the reason so many have touched off on the pistons, and the reason some have bent valves...

Also made some locator/shims for the springs to build up pressure and keep the spring from walking around in the seats.

Lot of stuff that's not being made public here, and it's pretty misleading to those who are starting down this path..

When we bought our engines, this thread had been up for quite a while and it looked like some stuff was pretty well figured out. 310 cam is working well...heads decked this amount seems to be pretty safe...little bit of valve float...these springs fix the issue...We got some good deals on two engines, talked to a few people, and went with what was "working". First trip out broke a rocker boss...after a lot of head scratching, and trying to figure out why everyone else is not having any issues and why we were...we're using the same stuff....we figured out what the issue was, then it made absolutely no sense why nobody else was having problems....turns out they were...we're shimming the springs we said to use....i bent a valve...pretty much everyone running the 310 cam touched off on the piston....turns out, things are not quite as straight forward as they seemed. Lots of stuff happening that's not being talked about..

I'm not mad at anyone but myself, or pointing fingers at anyone else, but I don't want anyone else to run into the same problems we have. We should have taken measurements on our own. We did not do enough of our own research, but we were under the impression that something that "worked" was already out there. We should not have trusted everything we read. It's cost us a bunch of money. It is what it is, but to those starting down this path, do your own measurements, make sure you can get your rocker geometry the way it needs to be, make sure you aren't going to have issues, because about half the people who've used these have had issues that are not being made public. Nothing is really "figured out" yet.

I do think most have been lucky and not broken anything yet because the rocker bosses on the newer engines are much beefier. The ones that have touched off have been lucky enough to have the adjustment screw pop back on top of the valve stem rather than ripping the boss out when the collision happened. But if you keep smashing into the pistons, you're eventually going to break something. The valve stems and the adjustment screws on the intake are both extremely small. Big lift cams are going to cause some issues that need to be addressed. I'd really like to find a way to use lash caps, but there just isn't enough valve stem there for em. We will likely step back down to a stock cam or at least a smaller cam at some point...just hoping we make it through the weekend at caddo first.

And for the record, I agree some have "thrown" stuff together and ran and said it ran good, BUT the one that has the most hours has not had any issue because they took the time to measure and check and did not try to put in a radical cam. We knew it was tight and there wasn't much room for error in any direction, however, you can't control what decisions someone else makes to do to their own and unless you literally walk the same path they did, what choice do you have other than to trust them... I hope you get it working like you want it to. Bottom line is this engine is still better than the others anyday of the week. The vast majority would be happy with it in its stock form.

This is what I was responding to, but "Now venturing more towards a lower lift and more decking due to piston to valve clearance. " And that wasn't the first mention of the valve clearance. I was just responding that I don't really think there is a clearance issue. If the cam alone was causing the valves to hit the pistons, they would run into each other at idle, or turning the motor over by hand. They don't hit at idle, they don't hit turning the motor over by hand. They hit when the valve is stuck open... When I get a chance, I will try to measure the actual clearance.

I'm not trying to shit on the parade. I'm not singling you or anyone else out. I just want the info to be out there, so that others venturing down this path don't make the same mistakes we did, or several others who aren't talking about it. Luckily it looks like we are the only one's out a bunch of money due to a failure, but it's only a matter of time if the issue doesn't get addressed.

I've always known the valves didn't hit because of the lift or timing and never mentioned they did, sorry if I misled. The original cam was selected from degreeing the stock one in Bugs engine (the first one and only one that's been accurately measured that "I" know of) and only decked .025" due to how much clearance there is. With a 310 there is only .021" of clearance at .050" with the heads decked .025", what happens if you deck .025" more? That's all I was talking about at the time... Yall have fun with it, I'm out for now.

Ok. I was talking about issues that had already happened without the heads being decked that much. Most of the guys that touched off were decked .020-.030. We were decked .025. We didn't touch off because of clearance. The several times recently I've seen clearance mentioned, I assumed we were talking about the guys who have actually banged into the pistons, and I just really don't think that's due to a simple clearance issue. I guess we're talking about different things.

Yup

Like I said, not singling anyone out, and don't have anyone to be mad at but myself. Just thought the info I posted could prove to be very useful to someone else and I wish I would have had it before we broke something.

I saw the valve clearance thing come up a few times in the last couple pages and that triggered a response from me. Maybe for the wrong reasons, but still needed to be said, IMO.

Yup

I ran the 310+6 with .025 heads. I touched off on the #1 cylinder at some point. I have prolly 125 hours with that combo. Probably happened on one of the occasions of banging away in the grass and looking down and seeing 6k+ rpms.

Yup

This game is rigged.

You shut your stupid face!

I ran mine for longer than anyone at high rpms. But I was also taking a,chance. We actually took p2v measurements and they were close on the intake. The exhaust had more. So I have a feeling that I also floated mine and banged 6000 when I hit a,sandbar. But because the top of valve stem is,very close to the keepers, sure if they floated and touched off it could have done some,damage. Now cb's heads that broke,are,the old recall heads. There different from what,we're running.

On another note, all we can do is provide assistance to those looking to make a swap. This motor has no limiter nor does it have Coils that,regulate the rpms. You fuck up, then you do damage. I actually had decent rocker geometry at .025" but I have recently decked more to a total of .050" and the geometry "on my motor" was still ok but I wanted it better. So I cut down my intake pushrods only .100". .050" off each side. Polished them back and the geometry is better. But at .025, with a .310 cam, I held 4950 rpms for 16 miles or about 35 min straight with no issues holding 33.9. So I believe I could have been his old style heads. MitchV touched off because he hit a float and banged almost 6000. Me too, mike (buddy of mine did as well with 6000+) so it's all relative I believe. Did I make mine better, sure, I centered the geometry after all the mods, but mine wasn't bad at .025 to start off with.

Only difference on the heads is the rocker bosses are bigger on the new ones. My motor already has the new heads. Would having the beefier boss have fixed the issue? No... Maybe it would have prevented the total failure at that point in time, but it would not have prevented it forever. It also doesn't change the fact that pretty much everyone running this recipe has smashed their valves into the pistons at some point in time, and nobody is talking about it, and others are still buying the same parts with no knowledge of these occurrences. Ours didn't smash together because we hit something. We were tuning the carb in open water. Touch over 4500, the above pictures are the results. We used the recommended springs...which it turns out were still being shimmed by those recommending them. We used the recommended cam, even though everyone running it has had problems. Just saying man...there's a lot of stuff being tossed around out there, and it's very misleading.

Everyone is acting like everything is good...when almost everyone using the most popular info in this thread has had problems...and nobody is talking about the problems or warning anyone. This thread is supposed to be informational and it's missing some of the most important information available....THE PROBLEMS.

No one has said in stone "this is what you need to use". Everyone is still " testing" and once again, the very first one has not had an issue at all. Like said above the ones we know about that did busted rpms way above anything under normal circumstances which create unpredictable valve spring harmonics. If you can't handle the repercussions of trying something different, go cry a fucking river somewhere else.

Damn.

To be more clear..

Problems are fine. In fact they are to be expected.

No one is crying by openly talking about issues that have come up. In addition, I don't think you can speak for everyone when you say "no one has said". You don't know what other conversations have been had or who has said what.

Also, not to be lost is how much all of us following the "pioneers" appreciate what they have done and brought to the table.

The point is to let's everyone make sure that as much of the info as possible get's put out there so others aren't following paths that have already proven to have problems. Or at the very least can be conscious of the problem to try and work around it.

Let me say again to be sure everyone catches it, I (and I think everyone) really appreciate the work, effort, and money everyone that started this whole process has put in.

Let's just keep the info flowing, and not limit it to only success. Let's share the failures as well so everyone can learn from them. If you don't want to do that then fine, but it is misleading to only talk about the successes , and talking about things that ultimately turned out to not work then not coming back to note that. Just don't say anything if you don't want to share it all.

Yes my first engine had that problem cb5331 but it happened to the boat in Alabama I didn't have it here to see for myself but after seeing your problem I called the guy and he is fixing it by simply shortening pushrods . We just started pulling heads to deck .050 and yes do to floating valves there have been 2 engines that had valves touch off on piston . Not one of these engines we are running is totally finished yet improvements are being made little at a time I am personally between two Kawasaki engines cams carbs and other shit 6000$ invested in this project and some change . I don't post much cause this site often has to much bullshit on it and I am very busy if someone wants help fine my number call or text I'm not hard to get in touch with neither is bugs Todd or banded and remember this is a project and in stock form it is easy for almost anyone on this site to install one but unless you have experience with building performance engines you may in counter problems this motor is all custom mods no one has a kit for it and know one yet has the hours on anything to prove that it won't fail .So I repeat if you are not a person like the rest of us that likes to spend money trying to make a motor a lil faster and have countless hours to waste you may want to just call Calen or aka or jamie to build you a Briggs that has everything available I'm sure we will eventually figure out what the best mods for the Kawasaki are but at the moment there are no perfect mod combinations yet but we are getting closer and are always willing to share if anyone ask.

The closest the intake valve gets to the piston with the 310 cam, plus four on timing, and heads decked .025 is over .130....I just went and measured...there is not a p2v clearance issue there because of the cam. With heads decked .050, that's still over .100 which is perfectly fine.

Nobody said anything is set in stone and we fully understand things are being "tested". The problem is when we're only telling the "good" and completely ignoring the "bad". Not only ignoring it, but continuing to send people down the same path because we refuse to acknowledge there is an issue. There is a guy just a few posts up that is in the process of assembling a motor with these same parts and had no clue any of this was going on.

I'm not crying a river, nor am I even pointing fingers. I'm saying if you're going to do shit like this, share ALL the info. Not just the good. This is not just one person having the issue. Almost everyone who's run this recipe has had an issue. People are banging pistons into valves and bending valves running this recipe... Why not make that shit public so others can take that into consideration? We had no idea there were problems or that other stuff was being done to make the parts suggested numerous times in this thread work properly, and neither does the guy just a few posts up.

Thanks. Ironically the valve touching cases all happened not long ago. Pushing them further I suppose. Most were revved way up. Not sure about CBs but something was different because it has not happened during normal rpms that "I" am aware of. That said, there is a possible rev limiter application that's been on the back burner that may eliminate that, but the guys "want" to find the limits.