Hello
Wondering what to expect when I bolt on this pipe with no carb work done.
Do I really need to rejet ?. Will I need to move the slide on the carb ?
It will also have the stock air cleaner .The pipe will have the quite core and spark arrestor.

thanks
gswarrior2002[img]i/expressions/face-icon-small-happy.gif[/img]

 

You will need to go up to a 152 main jet, and turn the fuel screw out a little, but that's all you should have to mess with. When I got my hmf my engine was stock except for the uni filter, and I was running borderline lean in the summer, and very lean in the winter. Rejetting isn't hard, the jet will only cost a couple bucks, and that's the only way you're going to gain any power from it. Without rejetting, your power will stay the same, or possibly decrease from the a/f ratio being off too much.

Here's a sound clip of mine doing a wide open throttle run up the road.
I don't have the quiet core, and some of the noise you hear in the clip is from my modified airbox lid, but it can give you an idea of what it's going to sound like.

 

152 are you smoking crack?

i kept STOCK jetting... and my quad ran PERFECT!!!

i have a cut lid, hmf, and some other misc stuff and i am only running a 147.5 main...

 

Check HMF's web site! They recommend a 152 mikuni with everything else completely stock. I was running a 148 dynojet, 1 size from the biggest in my jet kit before I swapped it for the edelbrock.

 

i don't think so...

also.. a 148 dynojet is SUPER lean.. that's lower than 140 mikuni

 

that pipe doesnt sound like anything special...in fact it sounded almost stock...maybe its just for the power then

 

it sounds kind of like stock.. but way better.. and the power it opens up makes such a BIG difference.. if i was in a gear any higher than 2nd and i got on the throttle it would usually bog.. or if i got in trouble i would have to downshift usually.. or in steep hillclimbs it was a FINE line between loosing power and just spinning tires...

with the HMF slipon i was able to pretty much accelerate UP the same hills i was having troubles with before... plus idk if anyone else thinks so... but my warrior just seems to have the PERFECT powerband at about 1/2 throttle in 3rd gear it just seems to get this power out of nowhere.. but anyways

http://www.zippyvideos.com/434949626...bl/*speedy2222

 

http://hmfengineering.com/jetting/index.php

Originally HMF claimed that there was no jetting require, but that was a load of crap. Why would they give the jetting specs on their website if it didn't need a rejet? Just open up the link and look! And even if no jetting was REQUIRED, you still need to rejet to get the a/f ratio right, and to get any power gains.

The biggest jet in my stage 2 dynojet kit was a 150! You have it backwards, a 148 dynojet is a larger number on the mikuni scale.

It doesn't sound even close to stock in person. It's much louder, over 100 db, and has a very deep tone that carries on forever. In that sound clip the recorder was sitting 40 feet away from my warrior when the engine started, maybe that's why it doesn't sound that loud in the clip.

 

CLICK IT

 

When I bought my warrior it had a 147.5 mikuni in it, and when I put the hmf on it was running hotter than normal, the headpipe was glowing like someone held a torch to it, and it was shooting 6 inch blue flames out the exhuast and popping during deceleration. If that's not a sign of lean, I don't know what is. When I rejetted it had more power, and there were no more lean warning signs.

Now, if a 147.5 is too lean, the stock 142.5 would be like 'burn a hole in your piston' lean.

And still, you have to pay attention to the whole theory behind rejetting. Your machine needs a specific air/fuel ratio to make maximum horsepower. It comes jetted from the factory to make maximum horsepower with the airflow the stock exhaust allows. If you add an exhuast system that allows more air to flow, you also have to add more fuel to the mixture to keep the ratio where it belongs if you want maximum power gains.

Now tell me, why spend hundreds of dollars on an exhaust, but not spend another 5 bucks on some jets to maximize your gains? It just doesn't make sense to me why people do this.