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KLX450R FAQ (new jetting, AIS, battery, etc.)

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Here's some pointers to some of the most common questions concerning the KLX450R:

Jetting: From the factory the bikes a jetted very lean. This causes the bikes to run hot and hard to start. Install a carb jetting kit from either JD Jetting or F2 Racing. Both kits come with detailed instructions and altitude charts (sea-level to 9000'+). An airbox mod (easy) is also included in the instructions. To access the carb you'll need to remove the rad shrouds (4 bolts), seat (2 bolts), fuel tank and petcock (2 bolts, 1 strap), remove the muffler (2 bolts), remove the lower rear sub frame bolts (2 bolts), remove the upper rear shock bolt, and loosen the airbox band clamp on the rear of the carb. Sounds like a lot of work but it should only take about 15 minutes. While you're accessing the carb, it's recommended to install an aftermarket fuel screw. F2 Racing makes a nice brass one, but they can be purchased many places.

AIS: This system pumps air into the intake between the carb and the cylinder head. When you back off the throttle you'll hear some popping caused by this system. It's easy to remove, and blockoff kits are made by F2 Racing and White Bros. (WB - use the CRF250/450X kit, it fits). The air pump sits under the right rad shroud. Remove the pump and bracket, remove the silver tube from the pump to the left side of the cylinder head and plug hole with plug from kit, remove black hose from pump to airbox and plug hole with plug from kit, and then remove air nozzle from intake and plug with a loctited screw (if using WB kit, use a bolt from the air pump mount bracket).

Battery: This is pretty straight forward. Make sure the battery has a FULL charge (not a charge from the dealer) before you go for the first ride. When not riding, put the battery on a Battery Tender.

Over-size fuel tanks: IMS (3.2g) and Acerbis (3.3g) make big tanks for the bikes. The IMS tank requires you to use KX450F rad shrouds (about $40/pair) and the Acerbis tank uses OEM shrouds.

Chain noise: Once you get a little slack on the chain they tend to get really noisy. I have found that checking the slack before each ride (per the manual) and making sure it's no more than 2" keeps it quiet. Once you get over 2.5" it clatters a lot! It's also a really good idea to replace the rear chain guide. They tend to wear quickly. TM Designworks makes an excellent replacement.

Exhaust: The stock exhaust is obviously very quiet and fairly restrictive. There are MANY companies that make exhausts for the bike and suggesting any one of those would just be by personal preference. If you're looking to uncork the OEM exhaust without replacing it with an aftermarket system here's two suggestions. The KX450F muffler will fit and used ones can be found easily. Another option, Pro Moto Billit makes a tip insert that fits the OEM muffler. The OEM header does have to be moved out of the way to be able to change the oil filter, most aftermarket exhausts clear the oil filter cover.

KLX450R owners: Please add whatever you feel relevant to help those trying to figure out what we've already gone through! :thumbsup:

Happy motoring! :thumbsup:

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Here is one more tid bit that made the world of difference for me (I'm 200lbs loaded):

Suspension: From the factory the bike is setup for someone that is 140lbs. Depending on your weight, new springs for the front and rear might be in order. There are many quality choices on the market (I found RaceTech the best choice in my area) - talk to your local shop to see who does the most suspension work in your area.

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Ron Ayers, besides having the KLX online fiche available, has a great reverse lookup tool. Punch in the OEM number for the KLX part and it will give you the other Kawi bikes that part went on.

I need a shifter. The KLX # is 13156-0067. Reverse lookup says the same part # is on an 06 KX450F.

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Very good write up and phlipper is there a website address? Is it just add dot com? It takes me forever on the Kaw. website to cross reference. Thanks guys.

I want to add there are flexible fuel screws now from R&D racing and I think XR's only. Helps to be able to get at it.

:thumbsup:

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As a new owner of a KLX 450 I can already tell that my bike runs way too hot, I am riding at about 3000 ft - 7000 ft most of the time and had a few questions?

1) any preferrence on the jetting kit? (F2 vs. JD)

2) what does the airbox modification for these kits entail? Anyone have pics on what you have done?

3) have you changed your coolant as well (engine ice, redline)? Or is this not necessary ofter making the jetting changes?

4) AIS Block off - will this modification actually help the bike run cooler or just give more power? Anyone have pics on how this is done?

Lastly - I have had one issue with this bike and it had to do with oil leaking from behind the front sprocket. Anyone else had this issue?

Thansk for your help.

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1) any preferrence on the jetting kit? (F2 vs. JD)

I have the JD kit. VERY detailed instructions and works great. I'm sure the F2 kit is the same.

2) what does the airbox modification for these kits entail? Anyone have pics on what you have done?

Just drill out the plastic rivets that hold the scoop on the top of the box under the seat. Easy....

3) have you changed your coolant as well (engine ice, redline)? Or is this not necessary ofter making the jetting changes?

Stock coolant, has never overheated since I rejetted..

4) AIS Block off - will this modification actually help the bike run cooler or just give more power? Anyone have pics on how this is done?

Not sure about the temp thing, but follow directions above and removal is easy.

Lastly - I have had one issue with this bike and it had to do with oil leaking from behind the front sprocket. Anyone else had this issue?

Hhmmm, not me...

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I tested out the jetting this week, running much cooler now, spent 4 hours in the tight tight single track Monday, normally the gas would boil after 30 mins requiring my to wind it out down the straight away to cool down, but now it runs much cooler, the bike even feels cooler between my legs.

JD Jetting kit.

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Skid Plates, Works Connection is what I have along with the radiator cages. Others have Flatland. Hyde Racing makes a polymer one that Johnny Airtime had on the Baja bike. Whatever happened to his posting about that bike here?

Also Destry Abbotts webpage has a write up in the message section about his Ebattery setup for his 08 KLX race bike. Saves a couple of pounds at least.

If anyone gets a Wild Hair ProMotoBillet makes a really trick kick stand for the KLX. It tucks in better than the stocker. If I destroy mine somehow that is the one to get in my opinion.

Exhaust pipes. I have a Bills with a SA/ full system. Some have WB's full systems and some people have FMF with the Mega bomb header that they really like. Mine lost some lowend with the non Lowboy header and seems to have gained mid and up.

I just wanted to add some things that have been asked about a few times.:thumbsup:

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Just a quick note Applied Racing Products (951-694-3267) makes a AIS block off kit for KLX450R as well as a crankcase vent kit just installed both on my bike,plus a jd jetting kit and R&D flex jet fuel screw, bike runs great!

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IMS install. I used KX shrouds, petcock and gas drain. It eliminates the 9 o'clock position which the radiator then becomes vulnerable in a crash with the stock on full reserve.

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where is the AIS located??? does anybody has any pics??? what r u guys using to recharge the battery??? my battery always dies when I go riding:mad:

:lame:

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AIS is located near the right lower radiator. Runs from the right side of the intake casting to a bracket near the radiator then a metal tube to the left side of the exhaust. I used the CRF250X kit from XR only as it was less expensive than the KLX kit from Applied Racing Products.

If you don't need the headlight, disconnect it and your battery will be fine.. OR stop taking so many breaks during the ride! LOL

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or in between rides. i ride hard the whole time im on the bike, just like everything else i do.. :lol: the battery still seams to go dead over the weekdays when i dont ride

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or in between rides. i ride hard the whole time im on the bike, just like everything else i do.. :lol: the battery still seams to go dead over the weekdays when i dont ride

Have you had the battery checked at the dealer. I carried my battery to the shop and it checked out ok with the hand tester that they used. It still wouldn't keep a charge, so I took in the whole bike. Electrical system checked out ok, so they went ahead and replaced the battery. Never a problem since! I have a tender wired in but I don't have to hook it up anymore. The bike will start even if I don't get to ride it for a couple of weeks. No stator rewire no switch for my light, no nothing.

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Have you had the battery checked at the dealer. I carried my battery to the shop and it checked out ok with the hand tester that they used. It still wouldn't keep a charge, so I took in the whole bike. Electrical system checked out ok, so they went ahead and replaced the battery. Never a problem since! I have a tender wired in but I don't have to hook it up anymore. The bike will start even if I don't get to ride it for a couple of weeks. No stator rewire no switch for my light, no nothing.

same here. Batt was always going dead while I was riding. dealer replaced the batt under warranty and checked my charging system. charging system was good. I have not touched the kickstart since my new batt:thumbsup: . also the starter spins the motor like twice as fast since new batt.

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How does 148 on the Main and 48 on the pilot sound air box has snorkel removed and the exhaust has the pea shooter removed altitude about 100 metres to about 600 metres

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One solution to the overheating problem is to install a new radiator cap. You can buy one from the Kawi shop that is stamped with a 1.6 on the top ($25). This won't keep the bike from overheating, but it will keep the fluid in the radiator. I also have the FMF Q4 ehaust (supposed to be the quietest on the market) and a Dynojet Stage1 jet kit, which I recommend to stop the bike from overheating.

Unibiker makes a good radiator guard with support brackets to keep the radiator from folding back during a crash ($99).

Devol also makes a good skid plate ($99). All of these mods are easy to do at home with ordinary mechanic's tools.

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