KFX450r hard starting - Kawasaki KFX450 Forum

beetle420 · 11-06-2010, 06:02 PM

I have a 2008 KFX 450r that has had a hard time starting cold ever since I got it. I had read that this was a common problem but would go away once the bike was broke in. Thinking I was just having bad luck with batteries I have been thru 3 of them. I now have three good batteries. The problem seems to be when I have it choked the starter drags really bad draining the battery almost instantly. Almost like the compression is too high for that little battery. If I push the choke in it turns over easier but wont start most of the time unless warmed up. Even with a new fully charged battery my quad wont start easliy when choked(or whatever you call it on an EFI quad). When I hit the start button it will start to turn the motor over but gets really bogged down before it can turn over a complete cycle. Another thing is that this happens about 90% of the time. Every once in awhile it will just fire right up. It seems to be the initial turn over that really kills the battery. If I hit the start button with no choke and get it turning over then pull the choke out it usally starts. This is very annoying and I can't seem to figure out the issue. Another thing worth mentioning is I was tired of this problem so I installed a kick starter. So far I haven't found anyone who is strong enough to kick start it. And ,of course, when you tell someone that they want to try it. My buddy that is 6'4" 230 pounds can't kick it. Many others have tried with no success. It will turn over but it would take a superman effort to acctually make it start with the kick starter. After trying the kick starter I know why the battery is having a hard time. The motor, for whatever reason, is extreamly hard to turn over. Once its running it runs like a dream. It's probably one of the funnest quads I've rode. No other problems except it just won't start easily. Please help... I want to keep this quad but it's annoying me to the point that I want to sell it.
Thanks for any help.

Current quads
08 KFX 450r
03 Drag Banshee
99 Banshee
03 Predator x2
Previous quads
06 Raptor
08 Brute Force

strubby · 11-07-2010, 04:51 PM

Did you just make the same post on HQ? It seems the Procom ECU eliminates the difficult starting that the OEM ECU does, and also allows to to start WOT. As soon as I get the coin, I'm doing the upgrade, as mine has been hard to start from day one as well.

For the kicker, I've never used a kickstart on a KFX, but like any other bike, if the decompression valve is set and working correctly, it should NOT be that difficult to start. I'm only 155lbs and my TRX was easy to start first kick. Pull off your valve cover and make sure that is in spec per manual. Also, compression should only read 90psi (I think) if the decomp is working.

beetle420 · 11-08-2010, 08:43 PM

I guess it the auto decompression spring that broke. Little yellow spring under the valve cover (shifter side). Thanks for the help

beetle420 · 11-08-2010, 08:45 PM

Spring was $4. Took about an hour for me to install. First time I have ever worked on a 4stroke top end. Super easy fix... just alot of nut and bolts :-)

Djr-xc-racer29 · 11-10-2010, 01:52 PM

I've got the kicker kit on mine and it starts fine within a couple of kicks even from cold, it does sound like the auto decompressor isnt working!!!!

11-06-2010, 06:02 PM	#1 (permalink)
beetle420 Junior Member Join Date: Nov 2010 Posts: 3	KFX450r hard starting I have a 2008 KFX 450r that has had a hard time starting cold ever since I got it. I had read that this was a common problem but would go away once the bike was broke in. Thinking I was just having bad luck with batteries I have been thru 3 of them. I now have three good batteries. The problem seems to be when I have it choked the starter drags really bad draining the battery almost instantly. Almost like the compression is too high for that little battery. If I push the choke in it turns over easier but wont start most of the time unless warmed up. Even with a new fully charged battery my quad wont start easliy when choked(or whatever you call it on an EFI quad). When I hit the start button it will start to turn the motor over but gets really bogged down before it can turn over a complete cycle. Another thing is that this happens about 90% of the time. Every once in awhile it will just fire right up. It seems to be the initial turn over that really kills the battery. If I hit the start button with no choke and get it turning over then pull the choke out it usally starts. This is very annoying and I can't seem to figure out the issue. Another thing worth mentioning is I was tired of this problem so I installed a kick starter. So far I haven't found anyone who is strong enough to kick start it. And ,of course, when you tell someone that they want to try it. My buddy that is 6'4" 230 pounds can't kick it. Many others have tried with no success. It will turn over but it would take a superman effort to acctually make it start with the kick starter. After trying the kick starter I know why the battery is having a hard time. The motor, for whatever reason, is extreamly hard to turn over. Once its running it runs like a dream. It's probably one of the funnest quads I've rode. No other problems except it just won't start easily. Please help... I want to keep this quad but it's annoying me to the point that I want to sell it. Thanks for any help. Current quads 08 KFX 450r 03 Drag Banshee 99 Banshee 03 Predator x2 Previous quads 06 Raptor 08 Brute Force

11-10-2010, 01:52 PM	#5 (permalink)
Djr-xc-racer29 Senior Member Join Date: Mar 2008 Posts: 120	I've got the kicker kit on mine and it starts fine within a couple of kicks even from cold, it does sound like the auto decompressor isnt working!!!! __________________ 08' KFX 450r - Pro Armour fat peg nerfs with heel gaurds, Pro Armour kill, Shockwears, Power madd handgaurds, 1" scar industries bar risers, BKT H-Ds tyres, DG x2 pipe, DG national front bumper, Denton adjustable steering damper, Quad tech seat, PRM rear skid plate, Lonestar axle, IMS big tank, Fluidyne big radiator, A-arm gaurds, Fasst flexx bars, Fuel intake, J'n'J industries chassis + a-arm skids, PCIII, TCS triple rate front shocks, kickstart kit, Douglas beadlocks on rear, custom Planet atv's grafix (thanx Rich), race no - 88 Long Travel front end on its way!! 08' KFX 450R - LRD head and cams, ims tank, AC nerfs with built in heel gaurds and big pegs, twist throttle, DG national bumper, full chassis skids, LRD full exhaust, PCIII, Monster energy grafix + shock covers, intake mod, road registered, douglas front wheels, fluidlyne big rad, ITP tyres, Renthal grips, 2004 Yamaha Warrior 350 97 KDX 200 87' Garelli 323 trial 86' tri-z trike

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11-07-2010, 04:51 PM	#2 (permalink)
strubby Junior Member Join Date: Jun 2010 Posts: 4	Did you just make the same post on HQ? It seems the Procom ECU eliminates the difficult starting that the OEM ECU does, and also allows to to start WOT. As soon as I get the coin, I'm doing the upgrade, as mine has been hard to start from day one as well. For the kicker, I've never used a kickstart on a KFX, but like any other bike, if the decompression valve is set and working correctly, it should NOT be that difficult to start. I'm only 155lbs and my TRX was easy to start first kick. Pull off your valve cover and make sure that is in spec per manual. Also, compression should only read 90psi (I think) if the decomp is working.

11-08-2010, 08:43 PM	#3 (permalink)
beetle420 Junior Member Join Date: Nov 2010 Posts: 3	I guess it the auto decompression spring that broke. Little yellow spring under the valve cover (shifter side). Thanks for the help

11-08-2010, 08:45 PM	#4 (permalink)
beetle420 Junior Member Join Date: Nov 2010 Posts: 3	Spring was $4. Took about an hour for me to install. First time I have ever worked on a 4stroke top end. Super easy fix... just alot of nut and bolts :-)

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