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Discussion Starter #1
Well like everyone already knows, the awesome factory dual carbs that come with the 660R. Anyway. I live in an area that is approx 2700' and go quading up to 5500'. I ride a stock raptor with a K&N air filter and dyno jet put in. I had problems with it running rich on the top end. Adjusted carbs accordingly (Also adjusted the floats, person who put them in didn't adjust them) and now having a little trouble starting when cold. Warm, starts great, cold - pain in the....

So i have the idea of putting Barker duals on and one of those Edelbrock carbs on. The dual exhaust for that extra power and sound and the Edelbrock carb for easy adjustment (one adjustment knob) for change in altitude. Not to mention the headache of adjusting two carbs instead of one.

Now I'm pretty much a noob with this whole carb adjustment thing. Can anyone give me an idea what to check/ adjust to fix this cold start problem. Also your opinion on the exhaust and carb choice.

One more is air box. Ive read that there are alot of different options for airbox mods. I need a mod that will keep most debris out (as i ride on some occation trails) yet allows the engine to breathe alot better. Or would it be better to have two options and just exchange airboxes before riding that day?

OH, and one more thing lol. Rims? what type of rims do most of you run? Aluminum rims just don't stand up to the woops in third gear, but also the weight of steel doesn't appeal to me either. But then agian its already a heavy peice of ....

Your opinions would be awesome to know.
 

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Master of the Electron
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1st, Welcome to the forum!

Cold starting problems are often due to the intake valve adjustment being too tight -as they wear the clearance tightens up... when's the last time the valves were adjusted? Usually, if you can pull start the bike, but it won't start with the starter motor its tight valve clearance...

If the bike runs well once its been started, then the jetting is probably ok, and the valve clearance may well be the culprit.

Modifying the airbox requires a LARGE change in jetting - way more so then modding the exhaust. If you're going to change it, plan on jetting appropriately and leaving it that way. Many of us run without the lid, or without the box altogether without any dirt/debris issues - the filter does a good job.

The only time I suggest making on the run changes to the airbox is if you make large changes in elevation regularly. If you drill a bunch of holes in the lid, and jet lean to optimize performance for your highest elevation, then as you drop in elevation significantly, you can put duct tape over some of the holes to richen up the mixture (as necessary for the elevation change). THis is the easiest way I can think of to correctly modify mixture when you make a 3 or 4 thousand foot change in elevation.

AFAIK, the Edelbrock is no easier to change mixture than the Rappy carbs - the screws on both are just for idle speed mixture - if you need to change the overall mixture (due to large elevation change) they both still require jetting changes (or the trick I described above).
 

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Discussion Starter #3
Cold starting problems are often due to the intake valve adjustment being too tight -as they wear the clearance tightens up... when's the last time the valves were adjusted?

If the bike runs well once its been started, then the jetting is probably ok, and the valve clearance may well be the culprit.

Modifying the airbox requires a LARGE change in jetting - way more so then modding the exhaust. If you're going to change it, plan on jetting appropriately and leaving it that way. Many of us run without the lid, or without the box altogether without any dirt/debris issues - the filter does a good job.
I had the carb torn apart last year for a cleaning and adjustment (for the running rich on the top end). I thought I had it right, seemed to be working fine. But as time progressed, i noticed it was getting harder and harder to start when cold. --I'll have to try what you said and adjust the intake valve a bit. -- Maybe this might help as well, during cold start i would try a few times without choke. Then with choke. I am getting plenty of spark and the spark plug would be moist at this time. I find the best way to start it would be getting on it and rocking it back and forth while on the start switch *not good for the starter i know* ...

I plan on putting on dual exhaust, thats a given. Just don't know what is the best (as in performance wise and reliablility). Rejetting is a given. If i add more air (airbox mod and exhaust) i know that rejetting will be needed. With the Edelbrock carb, it comes with several jets and step by step instruction on adjustment (and there's always google). I'm more or less just asking how i can fix what i got now, for the time being until all my parts are here to tear apart. Riding season is upon me and im itching to ride, not too sure if my parts will be all here in time (needing further education on what to buy and the coin to buy it all).
 

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Master of the Electron
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I've added more to my original post (apparently after you answered), so make sure you go back and read the whole thing again.
 

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Discussion Starter #5
I've added more to my original post (apparently after you answered), so make sure you go back and read the whole thing again.
LOL Ya man thats weird, guess I'm just to fast and eager for this site lol.

Ok, for the carboration issue i have been having, I think i'll try what you said about the intake valve and see what i can find.

As for the airbox issue, its a good idea but kinda "farmerish" if you know what i mean. It might not be that reliable, don't you think? I was thinking if i switched to the Edlebrock carb i would only have one carb to deal with (with the change in elevation) vs two, and would be alot simpler to adjust, no? right now how i compensate for the elevation change is changing a knotch on my main. Seems to be working but is a complete hassle to do. What i have been hearing with the Edelbrock, is you can just reach down and adjust a couple screws (air fuel and idle)... am i reading wrong?

The airbox i have been looking around and there are a few made of aluminum without no lid. little bit more stable but just wondering how it is for airflow on trails. Does it allow alot more airflow without the hazard risk of building up with debris? Then i have also seen kits available with two K&N filters with no box. Are these just strickly for tracks and dune? my guess is if you get any moisture around it (Like going through a stream or puddle) she will suck it up pretty quick no?
 

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Master of the Electron
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If you object to the 'ghetto' use of tape, then get two lids, one with many holes, one with fewer... many holes for high elevations, fewer for lower elevations, or an aluminum or plastic plate that you can screw on the lid to cover some of the holes at lower elevation... sure beats changing jets.

And, again, as far as I know, the Edelbrock still needs to be rejetted for changes in mid range and WOT mixture, the screws only affect idle to 1/4 throttle... somebody with an Edelbrock want to chime in here?
 

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Discussion Starter #7
Ahh, i get ya. See that makes perfect sense for the function of the Edelbrock. Maybe i just misread the functionality of it. Ya I think i might do the two lid funtion. Seems the easiest and most reliable.

Do you know of anyone with aftermarket exhaust on their raptor? if so what kind do they use? and how well does it perform? I only want to go with full exhaust, no slip-ons. From what i can find on the web here is that most people rave about the dual exhaust. Lots of people use the LTE and the Barker exhaust. Theres also the Monster exhaust (never heard of them).

Also sport quad rims. Something strong yet fairly light weight. Know of any? or what people usually use? I'm not too sure of front tire brand yet, but Maxis Razer 2 are catching my eye for rear. Right now i have Bear Claws and they kick ass, but looking to try something new.

If no imput, thanks for your help with the carb and airbox concern. San Diego huh? Man would love to go riding down there lol.
 

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Master of the Electron
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Forgot to mention - progressively worse cold starting issues almost always point to tight intake valve clearance.

As to aftermarket exhausts, I prefer CT, obviously, but you'll get proponents for nearly every brand... I'd suggest you find a good brand that has features you like and go for it. The overall difference between one brand and another is small compared to the gains by doing it with any of them.
 
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