Thanks Raptorraz... that's what I thought I was hearing before.

Now , with the power increases in KPX and other carts like them, I wonder where they stand??

-Steve

 

uh ohhh, do you still think the yerf head is worth it?

My valves are backordered, so I can still cancel the order if I want,
However, if the power increase is likened to adding the pipe and intake it will still be worth it to me. There are very few hills it will not climb now, it just climbs them too slowly. I have always thought (since adding the pipe) that mine accellerated really good, in fact most people remarked that they were suprised how well the 150 ran. Its just that it runs out of steam and ends really flat on the top end.

I would like to save my money but I think I am too curious to not try it now, I just gotta be tinkering on something. I will probably put the head on when I get it and then give a report. Shortly after I will shave some material off to raise compression and see how that goes (assuming it actually fits with my cam and rockers)

 

The ported Yerf head was a MUCH bigger improvement than when I just added the pipe and filter.

 

OK, yerf dog customer service rocks. (even though they are extremely expensive)

They next day air'd my parts in and I got them friday. I spent a little time porting, mostly around where they machined the vavlve seats, it was very sharp there. Valves are much larger than the other head, I didn't feel a whole lot of porting was necessary, the casting was better than the other one, not too much even needed to be done to get the gasket to match. I put the head and valves in and the only problem I noticed was that I had to back the valve adjustment screws out quite a bit from there previous settings on the old head. Hopefully this doesn't mean my springs are going to be too weak. I didn't bother to measure the valve length before putting the head on so I don't know if they are a little longer or not, I was not about to take the head off and back apart to measure.

Started up immediately, my twister still is not jetted perfectly more on that later. Anyway, I drove it and didn't "feel" any large improvement in power. Low end seemed exactly the same, however driving it down the road wide open I did notice that it revved higher and pulled a little harder at the higher rpm. Driving around the cul-de-sac I also noticed that it went faster, fast enough to slide the back tires all the way around the circle instead of having to whip the steering wheel to get it to slide (pavement). So it was definetly faster, just not the kind of seat of the pants change I got with the pipe/intake. (Also, I am not sure but I think it may have hit the rev limiter down hill, never even got close before)

I don't think I am going to get the full advantage until I mill the head to raise compression, thereby giving it improved top and bottom end hopefully. Although it pulls good at low rpm, I think doing this will improve it. This is similar to my experiences with putting a cam in a harley. The cam kept the valves open longer making it breath better but also lowered the compression of the engine. It ran great at high rpm but actually took torque away from the bottom (very dissappointing). I later learned that you have to mill the head to kick the compression ratio back.

My conclusion so far is that the pipe made a better cost to power ratio than the head. I will definetly be milling the head soon though, so if anyone cares or is even still following this thread I will report back then.

Here is a little jetting info, I have been running a 140 (they sent me a 145) main in the cart, it seemed to be ok, but lately it seemed to be almost popping, not accepting full throttle well. I took the uni filter off and it ran the same, no change whatsoever. I then took the intake tube off, now runs GREAT, I would not have thought a simple short piece of pipe would make any difference in jetting. I am now going to try a 130 or 135. I was never able to really read the plug because of the large amount of oil getting by the valves. The valves and combustion chamber had a lot of carbon buildup on them.

One more thing, the exhaust gasket carter sent me was horrible, my old one was leaking pretty bad, the carter one was even smaller. I went to the local honda shop and got some copper ring thing that was just a little too big. I lightly hammered it spinning it around a broomstick to get it to fit. So far this is working great, the inside diameter is almost exactly the same as my pipe and exhaust port.

 

I also wanted to add, if someone is preparing to buy one of these:

I went to gander (again) and saw the new 2005 Carter Talon 150 which had several updates including totally new reverse gearbox, snorkel, hubs, dash I think, maybe a few other things. But the thing that got my attention most was the exhaust. I looked underneath (I'm a tire kicker) and the head pipe coming off the head is now MUCH larger, I would say it might even be as large as my aftermarket pipe. If I were to buy one I am not sure I would even bother putting a new one on. At the very least you could cut the muffler off and use the headpipe for your own in-expensive performance exhaust conversion.

I would say this is one of the reasons the manufacturers are claiming more hp. I doubt this exhaust would need to be upgraded, the snorkel however looks like a bad idea (to me). looks like you could get away with just upgrading the intake (keep in mind, I haven't actually driven one)

just my 2 cents for anyone in the market for a buggy

 

What aftermarket pipe are you using? My Toy Junkies pipe is the same diameter as the stock pipe.

 

The eastside pipe, the INSIDE diameter is just under 1", I think 15/16 which was the same dia as the exhaust port. The exhaust canister itself is 2.25" I think. The pipe steps up quickly, again "I think I remember" 3 times before it gets to the canister.

If this is larger than yours it may explain the larger increase in power from the pipe versus the yerf head that I experienced.

 

Thank's. I'll make a trip down to Eastside and check it out.

 

I HAVE A 2005 TALON 150 THAT I BOUGHT A WEEK AN A HALF, AN D I DROVE IT IN THE DESERT WHITH MY DAUGHTER AND IT LOST POWER ON THE SAND, BUT RODE GREAT ON HARD DIRT ROADS.
I WOULD LOVE TO FIND OUT WHERE YOU GOT YOUR PIPE AND INTAKE, WHAT BRAND ARE THEY. THNK YOU

 

Allright, I actually measured the OUTSIDE diameter of my eastside pipe and the stock one. not as much difference as I thought. I did not want to take my eastside pipe off to re-measure the id but I know at the head it was 15/16, it must bottleneck down a bit right after. I think the id of the stock was .75"

Stock .865" Aftermarket 1.05", not as much difference as I thought, it just looks a whole lot bigger.

the stock pipe was actually sticking into the head past a squished gasket when I took it off. Not welded very well at all, ended at an angle also instead of flat.

Also, I put a new 125 main jet in and it runs great, sounds different even, kind of a braaaaapppp instead of a flat burrrrrrrrrrr

going to be test milling my original head soon to see if I can do it my self.