250R NA Build - Ultimate

[mgentz]

I'm at 112 mains 40 pilots and the fp needle 3rd clip. Its off but I'm leaving it for right now.

[tubarney]

news from the dyno isn't good.

It's making 20hp. The power curve is all over the place. What I thought was lean jetting was actually nearly perfect.

[choneofakind]

Waaaa? How's that even possible?

[cuong-nutz]

Originally Posted by choneofakind

Waaaa? How's that even possible?

word.

[mgentz]

So where does the tuner recommend you put the jetting? Mine is a bitch to start so I know that I have to go up on the pilot.

[mgentz]

Also what jetting WERE you using? How many miles did u ride like that? Top speed runs? Full throttle? Top rpm?

What on earth could be wrong man?

[tubarney]

Can anyone take a photo of their ignition coils showing the color of the wires that connect up to the coils. I'm thinking I might have the wires mixed up.

Either its that or the cam timing is out.

compression is at 165 for both. Jetting is perfect.

Its running 110 main, no washers, 40 pilot. The only thing he had to do was remove the washers to get the jetting correct.

This is the dyno graph. The bottom lines are the AFR.

[Racer x]

A bit confusing . To many runs . But the bulk of the A/f looks like 13 to 1 that is good. But the power is 25-32hp
You need to get above 35 deg of ignition timing. What pistons are using? Why only 165 psi of compression .

[tubarney]

The STD line is what is was before I modified the engine.

The engine makes 25 max now which is the bunch of other lines under the one on top.

The line at 20hp is with the exhaust baffle removed.

[tubarney]

I got J&E 12:5's in there.

I had the coil wires hooked up wrong. But for some reason it doesn't seem to be the problem.

[Racer x]

You should have 180-200 psi of compression.

[tubarney]

Originally Posted by Racer x

You should have 180-200 psi of compression.

It gets between 165-175. I'm pretty sure longer duration cams drop the compression, also my combustion chamber is slightly bigger than stock.

I figured it out. It has to do with the cams. Timing is out even though the marks line up. The lobes should be at 45 degrees facing up and away from each other when piston #2 at TDC regardless of whether you change the duration. Duration changes occur with changes in the lobe itself.

On the #2 pistons the lobes currently face about 22.5 degrees above horizontal axis. If I were to swap the cam sprockets and put the cams the other way around it would make the lobs face 22.5 degrees either side of the positive y axis.

I either have to swap the cams or move them closer together and ignore the timing marks on the sprocket.

[tubarney]

I have the cams in the wrong spot. I'll switch sprockets and their places and we should be good to go for Monday.

[Racer x]

I have a deg wheel and adjustable sprockets. But have not gotten to it. I first need to mount the deg wheel on the engine. Then atach a dial indicator to the head and measure the cam movement.

Problem 1 how do you attach the deg wheel?? A special bolt that will hold the wheel AND still allow you to turn the engine is needed.

Problem with that is the deg wheel must be mounted accurately. If the bolt turns while turning the engine then the deg wheel is not in the correct location.

Problem 2 how do you mount a dial indicator on the head to measure cam movement? The cams are covered. Maybe drill a hole to allow the dial indictor pin to go through a touch the cam.
I just line up the dots with stock cams. That is also why the engine makes 32.5 hp.

[tubarney]

Originally Posted by Racer x

I have a deg wheel and adjustable sprockets. But have not gotten to it. I first need to mount the deg wheel on the engine. Then atach a dial indicator to the head and measure the cam movement.

Problem 1 how do you attach the deg wheel?? A special bolt that will hold the wheel AND still allow you to turn the engine is needed.

Problem with that is the deg wheel must be mounted accurately. If the bolt turns while turning the engine then the deg wheel is not in the correct location.

Problem 2 how do you mount a dial indicator on the head to measure cam movement? The cams are covered. Maybe drill a hole to allow the dial indictor pin to go through a touch the cam.
I just line up the dots with stock cams. That is also why the engine makes 32.5 hp.

Degree wheel that is metal. A 9 inch is perfect. Flywheel is magnetic. Place a paint mark on the back of degree wheel and flywheel to ensure is has not moved when you take your measurements. You need a centre hole in degree wheel bigger than crank journal.

The dial indicator part is a bit more tricky.

I would do that with my Beet cams. I have already tried to get the details of when the valves open and close but they don't have them. Or at least they don't speak that good english.

[Racer x]

I think the deg wheel is not steel. I will check. I have an extra clutch basket. I could mount it on that side. I might make this a project.

[cuong-nutz]

From back in the days of Honda tuning, you could degree the cam by placing the dial indicator in the valve retainer. just make sure it's square. Could also degree the cam with it out and set it up on some roller bearings like that as if you were balancing a wheel.

[cuong-nutz]

Originally Posted by Racer x

I think the deg wheel is not steel. I will check. I have an extra clutch basket. I could mount it on that side. I might make this a project.

Even if it wasn't you could probably just attach it some some thin gauge sheet metal.

[Racer x]

You need to have the engine assembled to do what I want.

http://www.enginelogics.com/degree-d...ead-camshafts/

[mgentz]

So the cams are your issue? Have others experienced this with the BEET cams?

[mgentz]

I do wonder why mine is such a pain to start....?

[tubarney]

I remembered it don't matter which cam is in the intake or exhaust.

I did find a problem but.

Any ideas how this happened? it is the exhaust cam.

[cuong-nutz]

Damn, Brad. Seems like the camshaft chipping at the lip is starting to become a common issue.

http://www.ninjette.org/forums/showthread.php?t=94695

[Racer x]

You need to rock the crank back and forth so the cam is not pushing on any valves before you unbolt the cap. I don't think that will hurt anything . But it sucks.

[tubarney]

Originally Posted by Racer x

You need to rock the crank back and forth so the cam is not pushing on any valves before you unbolt the cap. I don't think that will hurt anything . But it sucks.

Yep I unbolted it last night at TDC for piston #2. The exhaust valve on #1 is partially open. I bolted it back down to rotate it to before TDC so the exhaust valve was not open at all. A simple mistake that will cost me 200 bucks. I'll have to run a set of stock cams for now until I can get another beet cam.

So thats crap because the cam is stuffed and it is not my problem.

I pulled the head off and bores. Ill post some photos.

I'm taking the head to the guys that did porting to check for a bent valve or compression leak. The valves look good.

I'm still thinking it has something to do with the way I hooked up the ignition wires. The dyno graphs looks like it is losing a spark or something.

The peaks on the 25Hp runs show that it is trying to make the power, but something is cutting the power right back down again.

The dyno I use gives high numbers. The 30Hp is a stock engine with just a full exhaust. Its about 2 hp over. So 35hp would be about 38hp on this dyno. I'm getting 25 which is about 13hp under what I should have. I have 2/3 power.

[tubarney]

I'll get a photo of the rings.

[tubarney]

I'm thinking that because I had the left ignition coil wires hooked up the wrong way the cdi was being grounded and cutting the spark.

I'm going to take the coils down to auto electrician to test them. I will also take the wiring diagram down to see what he thinks.

[tubarney]

Here is the dyno graph close up in color. The top STD line is from 2 years ago.

You can see the peeks that are above the old engine where it should be.

The AFR lines are at the bottom, they show it goes from lean to rich around 8k revs.

Ignore the retarded lines on the left.

[subxero]

what changes in the way the engine runs after 8k rpms?

Your AFR's change with the power curve so i am thinking that this change is an effect of the engine issue and would not worry about that

[mgentz]

Originally Posted by tubarney

I'll get a photo of the rings.

There does not appear to be any contact

[mgentz]

Originally Posted by tubarney

Here is the dyno graph close up in color. The top STD line is from 2 years ago.

You can see the peeks that are above the old engine where it should be.

The AFR lines are at the bottom, they show it goes from lean to rich around 8k revs.

Ignore the retarded lines on the left.

You go above your std line multiple times around 7k. Then she starts falling off. I believe you said your cams were off so that could be a major contributor. The ignition could also be a source. Your compression is within spec but does seem low. I have a set of stock coils if you need them.

[mgentz]

I still have issues with starting. I'm going to retard the timing and go from there. Fuel seems to be an issue for me as well...going to need to play around.

[Racer x]

For testing the valves I use a minivac hand operated vacuum pump. It has an adapter that fits the ports and vacuum tests the valves ability to seal.

You can still use the cracked cam.

The stock ignition system is inadequate for any real performance work. The coils are 13 dollars on e bay.
The 35 deg ignition timing is nine deg less advance than you could have. And the rev limiter hits to hard.

[tubarney]

If I take the bores off can I still use the same rings?

How do my pistons look?

Considering the power curve is not smooth something is wrong somewhere.

[mgentz]

I use a leakdown tester... how do you use the vacuum pump? Wouldn't the rings still leak?

[Racer x]

If you go half way down I show how to use the vac. And at the beginning you can see how I learned about camshaft removal on a 250 ninja . Haha

http://www.ninjette.org/forums/showthread.php?t=89190

[mgentz]

@tubarney @Racer x

if it isn't one thing it's the other isn't it? Now my bike starts really well, however cylinder number one is cold. I checked spark and it's there. I checked leak down and I'm doing really well. I check compression and I'm doing well there. Do you think it could be carbueration? Mind you, i did rebuild the carbs 3 times already but I suppose I can go in for a fourth, I just wonder if that's really the issue.

[mgentz]

I'm actually surprised at how well it starts with one cylinder....?

[tubarney]

^^Thats confusing.

I'm pretty sure I figured out what happened to mine. Because I hooked the wires up the wrong way I have reversed the polarity of the coil. It will work but put out a less powerful spark.

I may have also damaged the coil. I will have to get them tested.

http://mgaguru.com/mgtech/ignition/ig104.htm

http://board.moparts.org/ubbthreads/...Number=7142908

[mgentz]

I have the stock ones if you need.

Ill let you know if a carb rebuild fixes my issue.