Spooph's 250 build thread

[Racer x]

the idea my builder had was to use aluminum discs with O rings or side shoulders and clearance for oil. He said the shaft was held still. Simple matter of removing the teeth from the gear and drilling a hole. Provided you know where the hole goes.

[spooph]

I don't have pics, and I'm very sorry. When I got it back I was in such a hurry to get it put back together I completely forgot to take picture, but you guys are right, the shaft it still in the engine, with material removed from the counter weights to provide clearance for the crank. The counter balancer drive gear which usually meshes with the one on the crank has simply been popped off. The last thing my crank guy did was to drill out 1 oil journal hole to fit on the bottom case to make room for a 3 or 4mm hex bolt. He tapped the bounter balancer shaft and bolted this bolt to the shaft. With the bolt in the shaft, and the bolt head in the bottom case journal, the shaft won't spin.

I tried my best to describe this as accurately as I could, being that I failed at taking pics...

[mgentz]

Originally Posted by spooph

I don't have pics, and I'm very sorry. When I got it back I was in such a hurry to get it put back together I completely forgot to take picture, but you guys are right, the shaft it still in the engine, with material removed from the counter weights to provide clearance for the crank. The counter balancer drive gear which usually meshes with the one on the crank has simply been popped off. The last thing my crank guy did was to drill out 1 oil journal hole to fit on the bottom case to make room for a 3 or 4mm hex bolt. He tapped the bounter balancer shaft and bolted this bolt to the shaft. With the bolt in the shaft, and the bolt head in the bottom case journal, the shaft won't spin.

I tried my best to describe this as accurately as I could, being that I failed at taking pics...

ok. I think I can mentally picture this.

Removing the gear will keep the crank from spinning it. Bolting it to the case keeps it from spinning. You used the oil galley hole for the bolt. I also imagine that when you say "The last thing my crank guy did was to drill out 1 oil journal hole to fit on the bottom case to make room for a 3 or 4mm hex bolt." you mean that he counter-bored the shaft so that the head was flush. Otherwise the bolt would crack the case.

The only theoretical question I have is about using the oil galley area for bolting, oil pressure and the clamped nature of the entire shaft. i.e. if you bolt it tight on one side, the other side clamps down as well. this would reduce clearance to 0 or very minimal and allow no oil to flow to the shaft. it would, however, keep pressure up.

[spooph]

Originally Posted by mgentz

ok. I think I can mentally picture this.

Removing the gear will keep the crank from spinning it. Bolting it to the case keeps it from spinning. You used the oil galley hole for the bolt. I also imagine that when you say "The last thing my crank guy did was to drill out 1 oil journal hole to fit on the bottom case to make room for a 3 or 4mm hex bolt." you mean that he counter-bored the shaft so that the head was flush. Otherwise the bolt would crack the case.

The only theoretical question I have is about using the oil galley area for bolting, oil pressure and the clamped nature of the entire shaft. i.e. if you bolt it tight on one side, the other side clamps down as well. this would reduce clearance to 0 or very minimal and allow no oil to flow to the shaft. it would, however, keep pressure up.

Maybe we're saying the same thing? He counter bored the crank case and bearing (since the counter balancer will no longer be turning) to provide a hole for the bolt to sit in, the bolt bolted into the counter balancer shaft. The counter balancer shaft isn't bolted to the crank case, the bolt is in the shaft, and the bolt simply sits in the hole, bored out, right in the bottom/middle of the bottom crank case oil journal to keep it from spinning. Then the crank cases are bolted together just like normal. Sorry for the repetition, just trying to give as many different ways as I can to explain it.

Concerning oil pressure, it is behaving a little bit weird the more I ride it... Sometimes oil pressure is quick, like a stock bike. Sometimes it take some time (20 seconds has happened) for the oil light to come off... Not quite sure why this is happening... I will keep you guys posted though.

Damn, really wish I took those pics now...

[Racer x]

My understanding is a zx12 oil reliefs valve is better than the 250 ninja one. But I have not investigated this yet

[mgentz]

Originally Posted by spooph

Maybe we're saying the same thing? He counter bored the crank case and bearing (since the counter balancer will no longer be turning) to provide a hole for the bolt to sit in, the bolt bolted into the counter balancer shaft. The counter balancer shaft isn't bolted to the crank case, the bolt is in the shaft, and the bolt simply sits in the hole, bored out, right in the bottom/middle of the bottom crank case oil journal to keep it from spinning. Then the crank cases are bolted together just like normal. Sorry for the repetition, just trying to give as many different ways as I can to explain it.

Concerning oil pressure, it is behaving a little bit weird the more I ride it... Sometimes oil pressure is quick, like a stock bike. Sometimes it take some time (20 seconds has happened) for the oil light to come off... Not quite sure why this is happening... I will keep you guys posted though.

Damn, really wish I took those pics now...

oh. got it. The bolt threads into the shaft. the head simply sits in the counter bore in the case to prevent rotation. Once the cases are closed up, the shaft cannot spin. This would also allow for you to plan where the oil holes point. Nice.

Is the bolt somewhat loose (top to bottom) in counter bore to allow for the oil to flow?

As for oil pressure, the first time I rebuilt the motor I sometimes had issues with oil pressure being slow to come up and turn off the oil light. I somewhat remedied the issue by filling the crankcase near the upper line level. This also helped to keep the oil light from coming on during hard stops. Once I put in synthetic oil, I no longer had this issue. However, you need to wait a while before you put in synthetic oil in order to allow for proper break in.

[cuong-nutz]

Just don't plug up the oil galley nearest the stator side. That hole feeds the valve train. I forgot if the other side does or not. I'll do some digging regarding the zx12 oil pressure relief valve.

Mike, the oil will flow regardless since the bearings are grooved for it. The reason I mentioned about the oiling holes in the counter balancer is if they pointed directly at the oil galley holes in the case pressure would drop. By design, the shaft is suppose to spin and the holes help bring new oil in and out of the bearing as well as act like a pump and squiring oil through the galleys.

[mgentz]

Originally Posted by cuong-nutz

Mike, the oil will flow regardless since the bearings are grooved for it. The reason I mentioned about the oiling holes in the counter balancer is if they pointed directly at the oil galley holes in the case pressure would drop. By design, the shaft is suppose to spin and the holes help bring new oil in and out of the bearing as well as act like a pump and squiring oil through the galleys.

I know. I used to work for a company that made hydro-dynamic bearings for shaft sizes ranges from .5" to 36" and rpm levels of 10 - 26,000. I did, however, forget that the bearings were both grooved because I was thinking of the crank bearings mistakenly.

[Racer x]

Mike , you did use grooved center bearings on your crank didn't you?

[mgentz]

Originally Posted by Racer x

Mike , you did use grooved center bearings on your crank didn't you?

yes sir. As per the manual and required parts list.

I was confusing the crank v. balancer bearings there for a minute as the crank has a grooved center bearing and plain outer bearings. Most of the time these are yellow bearings. The balancer shaft has 2 sets of bearings and they are both grooved, and the same part number as each other. Most of the time, these are blue in color. Brain fart no longer.

[spooph]

Originally Posted by mgentz

oh. got it. The bolt threads into the shaft. the head simply sits in the counter bore in the case to prevent rotation. Once the cases are closed up, the shaft cannot spin. This would also allow for you to plan where the oil holes point. Nice.

Is the bolt somewhat loose (top to bottom) in counter bore to allow for the oil to flow?

As for oil pressure, the first time I rebuilt the motor I sometimes had issues with oil pressure being slow to come up and turn off the oil light. I somewhat remedied the issue by filling the crankcase near the upper line level. This also helped to keep the oil light from coming on during hard stops. Once I put in synthetic oil, I no longer had this issue. However, you need to wait a while before you put in synthetic oil in order to allow for proper break in.

That's it! Glad we got that figured out. Thanks for working with me to get that straightened out!

The shaft/bolt can wiggle a little bit, but not much. The guy who did it said he traced the passageways and that everything would be fine, if maybe a little low on pressure at idle. I trust him as he's been supporting himself building SBK engines for the larger part of his life...

Thanks for the tips on the pressure, I'll gives those a go!

[quarterliter]

When your oil light takes forever to turn off, is the bike warm or cold?

[spooph]

Originally Posted by quarterliter

When your oil light takes forever to turn off, is the bike warm or cold?

Cold, it achieves pressure within a second or two when it's hot...

[jkv45]

Originally Posted by spooph

Cold, it achieves pressure within a second or two when it's hot...

What oil are you using?

[spooph]

Originally Posted by jkv45

What oil are you using?

Kawi 10w40 dyno juice. With 2K oil changes, it's all I ever use...

[jkv45]

Originally Posted by spooph

Kawi 10w40 dyno juice. With 2K oil changes, it's all I ever use...

If you like conventional oils, use Shell Rotella T 15W-40 (warm weather only) or Rotella T5 semi-synthetic 10W-40.

I'd try the 15W-40 if you feel you aren't getting good pressure at start-up - it should increase it. I wouldn't recommend it for cold starts below 50 degrees or so though.

Rotella T 15W-40 is an excellent oil, and is inexpensive and easy to find.

[quarterliter]

Originally Posted by spooph

Kawi 10w40 dyno juice. With 2K oil changes, it's all I ever use...

I wouldn't recommend the kawi oil. How much is it per wuart?

[spooph]

Originally Posted by jkv45

If you like conventional oils, use Shell Rotella T 15W-40 (warm weather only) or Rotella T5 semi-synthetic 10W-40.

I'd try the 15W-40 if you feel you aren't getting good pressure at start-up - it should increase it. I wouldn't recommend it for cold starts below 50 degrees or so though.

Rotella T 15W-40 is an excellent oil, and is inexpensive and easy to find.

Thanks for the recommendation - I'm familiar with Rotella, but it gets a bit colder here for that, but worth a shot for sure! I think the pressure has more to with the passages, and that there is no less restriction in the system. Might have to get back in there and stopper some things up.

Originally Posted by quarterliter

I wouldn't recommend the kawi oil. How much is it per wuart?

I think I usually pay around $20/gal? or $5/quart? And I don't want to turn this into an oil battle, we don't need another of those, but Scott, the guy who did my crank said the engine looked practically new and wouldn't believe me when I told him I'd put 60K miles on it, so, the Kawi oil can't be that bad?!

[Racer x]

I use Repsol 10w40. but for everyday reality. Clean oil trumps any brand or weight.
I make 100% more power than the stock engine. Never had an oil related failure.

[quarterliter]

T6 5w40 is approx 20 bucks a gallon. But change interval is more important than what oil you use

[spooph]

Found oil problem - leak at the crankcase send to the head. Replaced the 2 little squish washers and oil pressure is as quick as stock. This would indicate, no problems from the counter balancer no longer turning.

[mgentz]

Originally Posted by spooph

Found oil problem - leak at the crankcase send to the head. Replaced the 2 little squish washers and oil pressure is as quick as stock. This would indicate, no problems from the counter balancer no longer turning.

good find! glad to hear the balancer is a viable deletion option.

[mgentz]

@spooph

How has your bike been performing after 1+ years?

[spooph]

She's just fine! Vibrates a bit more - I've had to tighten up a few things that have rattled loose here and there, and I'm using a lot more loc-tite, but the increase in mid-range is thoroughly enjoyable!