Endrigo Monster Power head and A11 cam is now installed!
 

It was my first time doing something like this. It was very very very easy.

Seats out and head cover off
http://i34.photobucket.com/albums/d1...t6000003-1.jpg

I set TDC before doing anything else
http://i34.photobucket.com/albums/d1...t6000009-3.jpg

Stock head off
http://i34.photobucket.com/albums/d1...t6000011-3.jpg

Stock head and Endrigo
http://i34.photobucket.com/albums/d1...t6000014-2.jpg

24mm intake compared to the 30mm intake
http://i34.photobucket.com/albums/d1...t6000005-2.jpg

Love how it is signed
http://i34.photobucket.com/albums/d1.../gt6000015.jpg

installed sorta
http://i34.photobucket.com/albums/d1.../gt6000017.jpg

I ended up not being able to use the 30mm intake without having a riser. There is just no way for it to work without it. I tried but it ended up causing the carb to be sideways and it really put a ton of stress on the couplings on both sides. I wasnt comfortable with it so i used the stock intake until i can order the riser.

http://i34.photobucket.com/albums/d1.../gt6000020.jpg

http://i34.photobucket.com/albums/d1.../gt6000022.jpg

More to come

My previous top speed was 35.5 and now it is 36.3. So i didnt gain much for top end like i was hoping for. As far as low end its very hard to tell since im riding in snow, tires just spin like they always have.

With a 38 pilot and a 130 main jet the plug electrode was super white
http://i34.photobucket.com/albums/d1.../gt6000025.jpg

Then i put in a 40 pilot and a 140 main, its a ton better but i think still too lean.
http://i34.photobucket.com/albums/d1.../gt6000030.jpg

Why is half the plug have color? Weird.

Both my carbides do that, dunno why, never put much thought into it.

Okay, just curious. Mine does not do that. I am still trying to get jetting correct on mine.
At first i was too rich at 134 main and still too rich at 126. Then figured out it was a bad fuel enrichment. So I had it a manual enrichment valve with nut and bolt. Now I am too lean at 126. Gonna try 134 today or tomorrow and hope to get it dialed in soon.

Ya i think tuning is going to be a pain.

This morning i checked the plug after letting it idle and reving it up to half throttle. Did that for like 20 minutes. Now its running rich at idle.

Did the same thing last night and i was to lean.

poor a/f mixture distribution inside the combustion chamber. you'll notice the side of the plug facing the intake valve will have more color. that's where the mixture is heaviest.
Poor Flame travel- ignition occurs on the intake side and the flame travels around the plug rather than having the whole chamber burn at once.
lack of intake velocity, not completely filling the chamber. and a little too much advance, plug fires before chamber is full and total compression is reached.
Lots of thinking and some crazy ideas went into this issue. Reshaping chambers to promote improved distribution of the fuel charge and flame travel. Some have tried cutting grooves in the ceiling of the chamber to direct flow. Indexing the plug- using shims so the electrode faces the intake valve when tightened into the head. A real pain to do. The old "splitfire" plugs with the split electrodes made claims of better mileage and performance by creating a wider spark to compensate for poor distribution.
The top of your piston tells the real story. the carbon build up areas are the cold spots, less flame.

Very interesting. Could a aftermaket cdi cause that misfire issue? I notice he has aftermarket and I have stock cdi.

get ur jetting correct u should have a much bigger increase in gains. I gained like 3mph on top end with just the a11. any more pics of the head with the intake and exhaust ports?

it's not so much an misfire condition but rather a compromise in intake, combustion chamber and piston design. The present shape of things works well enough on the average and can be mass produced. The actual spark duration between two coils could make a difference. A longer and/or stronger spark time equal a longer and more complete burn. It all happens in less than a blink of an eye so a coil that holds power a millisecond longer than another brand would be more efficient.

So after putting in the 40 pilot and 140 main jet and 1000rpm spring im now at 36.7mph.

I need to post a pic of the spark plug, see what you guys think.

In all honesty, I think you might be choking off the engine with the smaller intake riser. you have velocity in the intake but it gets disrupted once it hits the larger port and valve. You might have some trouble getting the carb tuned correctly.

Any suggestions on a riser?

https://www.buggypartsnw.com/index.p...ake-riser.html

This riser is also part of the intake/riser kit, and made just for your issue. There others out there, but this seller I trust.

Thats the one ive been looking at, most my aftermarket parts i get from Mike, its where i got the head and cam.

I was hoping for a cheaper option.

Honestly, you pay for quality and stores that speak english nowadays. I have seen some other risers, but I can't seem to find them right now. Good thing is, you only need one. Here are few others.

http://speccycles.ecrater.com/p/1723...6-intake-riser

http://www.composimo.com/GY6-Intake-...iser_p_16.html

http://enviromoto.ecrater.com/p/1675...manifold-riser

I was looking at those too, problem is they dont give any measurements. They dont even tell you if its 24mm or 30mm.

You could drill it out if you have a decent drill press, personally, I like the dual flange design of B/P/N/W over the hunk of aluminum and long bolts. The longer the bolt is, the more likely it is going to fatigue or stretch.

I am kind of questioning whether or not the intake is limiting me all that much. I mean if the intake is 30mm the carb is still only 24mm. The carb itself would be the restriction if i used the 30mm riser and 30mm intake leaving me right back where i started.

yes it (smaller intake) will restrict flow to the head even with the 24mm carb compared to using the ported one. think of the intake connection as a window between the head and the carb. You'll only be able to move so much mix at a certain rate through the opening. it's a mathematical situation with a pretty much fixed number. Open the window more (bigger intake cross section) and you can move more through. the carburetor can be adjusted, via jetting, and it responds to the air demand based on the vacuum pulse. The window can't be adjusted. of course there's a balance point between volume and velocity going in through the system.

Overall, these 150s are treated very simplistically for the average user. to really dial in any engine takes a good knowledge of intake to exhaust flow ratio and a means to make changes based on that knowledge and clear picture of where you want the power band and how to get it there. That's why Tom and others makes some $s doing what they do with the heads etc. They've spent the time to science it out and create proven combos. when the end user puts it all together, they still need a clear picture mentally of what they're assembling and how it all works as a whole.

Port match your intake to the head. You won't be able to use the O-ring though you will have to make a gasket from gasket material.

I am going to order the intake riser from mike, might be a few weeks before i can do that.

What you guys are saying makes sense and its obvious just looking at the pics of the stock intake and the 30mm intake that its restricted.

Im just suprised that it is restricting it so much that it is killing any gains. I mean the performance increase is minimal to non existent at this point. Again truly testing it is impossible atm.

Any updates on this

The project is on hold until spring. We have so much snow that i cant test it.

same here I cant work on either buggy because its been below freezing basically the entire month and snow also :(

ive haf snow on the groumd here for a week and half here in southern illinois with a couple ice storms to add to it. my buggy is frozen the the ground. it sucks. i usually keep her in the garage but had to do some work to my 78 blazer before it all hit.

I will update this thread as soon as the glacier recedes