Could an EVO get so hot that it smoke out the pipe. And also the carb when shut off. And let off an odd smell that lingers for hours...even sitting outside?

I think I'm super lean. During a ride today the rocker covers were so hot that I think you'd blister a finger if kept on the head for a second. Is that too hot?

 

Yes thats a bit hot to say the least. It sounds as if your timing is retarded a little and I'd say your ring seal is poor from thesmoke out the exhaust and carb

 

I'll have to check the timing tonight. How's that go...1100 RPMs you should see the timing mark (2 dots on mine I believe)? I forget...I'll have to check the manual.

I hope it's not the rings...I just got the engine back together. Leakdown test time or what?

 

I'd check it at 2000 rmp...this is full advance and you should see the LINE in the hole.(what ign. systemare you running)Yes a leak down test is a good idea.

 

It's the original timing plate / cam sensor with a SE ingintion module and SE coil.

Only 140 miles since the top end build.

 

Are you running a V.O.E.S. ?

 

Yes.

 

Rear Cylinder Front Cylinder
Compression:
1st compression stroke spike: 150 150
1st compression stroke settled: 110 120
Next 5 compression strokes: 185 185

Leakdown: 6% 6-7%
Both cylinder had all leakage through rings, none through valves.

Plugs:
Left in picture is the rear, right is the front.



[IMG]local://upfiles/23327/4B3E22FF1611422EB79653B8D231CA43.jpg[/IMG]

 

The compression looks more than good but.....you sure are getting a lot of oil in the combustion chamber. The rear cylinder will have to come back apart, sorry, but that isn't going to get better. Make sure you look at the front cylinder intake valve seal because a bad seal or seal that came off the guide will feed the rear cylinder with oil....how you ask....good question, as the rear cylinder is on the intake stroke the front intake valve is closed so the vacuum created by the rear cylinder intakewill pull the oil out of the front valve guide andthrough the manifold into the rear. (This is something that is over looked at times)

Second thing is the rear cylinder oil control ring is damaged or the second compression ring is in upside down.

The front spark plug is showing oil too but it's not out of the ordinary during break in.

 

That's a very interesting concept on the "scavenging" through the intake manifold. I did not take a very close look at the seals buried within the springs before installing the heads.

Recap / babble:

It's a rather odd situation as the smoke started like 300 miles or so after the first build...cam, cam bearing, adjustable pushrods, carb, exhaust, ignition module, coil and a couple other misc parts.

The first thing I did was check the plugs, they were looking rather good....clean with an oil ring around the first thread.

I then suspected excessive oil from the breathers, so I re-routed the breathers away from the air cleaner with some clear silicone tubing to get idea of how much oil was coming out the heads. Nothing significant and I still had smoke. However, I did encounter some odd debris in the which came out of the breather setup.

Next came a compression and leakdown test. I lost those numbers, but both cylinders were close to 110 or 120 PSI or so (slow to build up) and leaking more than 10%, one was near 15%. (Shortly before I did the cam upgrade, the compression was 155 front / 160 rear on a relatively cold engine.)

I pulled the exhaust and saw oil on the exhaust valves. Here's the rear valve. Here's the front.

Ah ha! Leaking exhaust valve seals. Strip the engine. Deliver parts to shop.

The shop said the heads looked good, the guides not far from new...no cracks, the valve stems good, seals dried a bit and could be suspect....nothing out of the ordinary for a 98 EVO with 30K miles.

OK...along comes the second build; a street port with a 5 angle radius valve job, new (slightly stiffer) springs, new seals, shave .060 off heads, bore cylinders .010, new pistons/rings, and .030" head gaskets.

Once I got all the parts, I spent an afternoon measuring and documenting fits including piston to valve clearance. To the best of my ability, everything in the top end came out within spec.

Got 'er back together this past Sunday night. Moday after work I washed the bike. After she dried, I went through a heat-cycle process starting with a 1 minute run and cooldown. First minute yielded a loud exhaust leak. Thought it was the head gaskets. I found that I had forgotten to replace the O2 sensor bung plug in the front head pipe. Oops. After viewing the video of the first start-up, I was shocked to see a puff of smoke at startup. Also note the light stutter or miss which seemed to disappear on the subsequent 2, 3 and 4 minute cycles when the choke was deactivated.

Tuesday after work I went for the first ride. Warmed up the bike for several minutes, and then rode pretty lightly a couple miles to the edge of town where I started the 30/60/30mph tenfold routine. Then rode between 40 and 50 mph for the next 10 miles to the shop that did the machining work where I was told to put a few hundred miles on it before worrying about it. First ride I put on 70 miles.

Now at 150 miles, I've still got smoke. The same smoke that I had after the fi