Noob Questions: Gutted Exhast? Fuel Octane?

[mzeblu]

First: I would like to say that I am very thankful for finding such a cool forum.
I have run an online phpbb and vBulletin with 30,000+ members until recently and want to commend all of your staff and your membership for really making this place feel like a community. The way you share information and not roast noobs like myself is really refreshing. I appreciate all of the helpful insight that I have gained thus far.

Questions:
I've used the search feature without really finding what is involved in gutting an exhaust.

I picked up a used Helix that runs ok but I must mod for more!

I've read threads that talked about more air (uni) + more fuel (rejet) gutting the exhaust and everything makes sense but I don't see what is involved.

My plans are to replace the CDI with a performance CDI, high output coil and iridium spark plug, do the 6" stainless drain pipe w/uni mod, rejet to #130 and it only seems natural to gut the exhaust as others have said.

While we are on the subject, is it better to run a higher octane fuel after you rejet? Is there any mod that would take advantage of a higher octane fuel?

Thanks,
Greg

[bam41]

Hello mzeblu. Glad to have you aboard! The basic beginning mods are as you have mentioned. 1.UNI 2.rejet 3.Gut exaust.
performance CDI and coil are also good mods. The Iridium plug is, in my opinion, only used when your engine is running at its optium capacity, that you might notice a difference. With that said, back to your question..

1. UNI mod. the standard is 6" drain pipe. I have actually went shorter to a 4". You can vary this depending on ease of installation. I figured closer to the carb, less time traveled through a tube = better response. That was 4" for my HH150.

2.your jetting will vary depending on the intake and exaust setups. this will be done as a 'step three' actually and not a 'step two'. But depending on what your jet is now, I would think 124~127.5 would be a good place to start. you will need more than one just one jet...trust me. you will have to tune your carb to your new intake and exaust.

3. Gutting your exaust is simply removing the canister and taking it apart. remove any restrictions inside. most have baffles and whatnot inside to create back pressure and reduce noise. We just remove all that stuff. That lets the engine get rid of the now more air you created with the UNI mod. It will alos let it get rid of the more fuel exaust you will creat during you rejetting mod.

This was just a general 'info help out'. If you have any questions on the specifics of each. Please ask. We will help you through the process.

FYI...higher octane should only be used on a high performance engine with lower compression ratios. Just use you regular unleaded fuel, perfered with no ethonol if you can find! lol

[BuggyMaster]

UNI is fantastic for best bang for the buck. In our testing, that without a doubt was consistent improvement under all conditions. For the exhaust, we actually used an FMF universale silencer and it was a pretty easy install and provided great sound and a little more umph.

Other areas for bang for the buck are in the clutch/variator assmbley. Just be sure which direction you want to go. For our particular riding environment, we run at top speed as much as regular running. That being the case, we found that a set of 13g sliders and a yellow main spring in the back worked best for us. Gave us a little better take off while we were still able to maintain a great top end. Some people opt for even lighter sliders and or rollers which will give you fantastic take off but you will likely lose some on the top end. Again, consider your goals when modifying the clutch area.

For the octane fuel, all of our toys get premium. Reason being is that consider the cost difference for a tank of regular vs a tank of premium. Maybe .30 cents? If you could drop .30 cents into a tank of gas and get all of the benefits of premium fuel...wouldn't you? We do.

Helix is a fantastic machine and his been our keeper for a few years now without regret. You'll enjoy it for sure!