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Bogging/ backfire

2K views 4 replies 3 participants last post by  Essa 123 
#1 · (Edited)
What up guys, in here today looking for some quality information. Due to production issues at work I have free time to work on old project buy also not a lot of cash flow

I'm trying to repair my ltr. Last year u was having fuel issues and while trying to work it out the starter clutch went out. Its sat untill now.

I put the starter clutch in and now in back to fueling issues.

06 ltr 450
Big gun full exhaust
Aftermarket filter lid off
PC3 with map from duno jet that matches the mods.

Person I bought it from said the engine was rebuilt from the guy he got it from but he only had it 2 weeks and switched to Yamaha. I dont know what was done in the engine but the quad had stickers for aftermarket parts that I dont know if are in it or someone just put the stickers on it.

So onto the current problem and what I have done so far. The quad will start up great and idle just fine. If you get on the throttle slowly it wonr big at first then will start to bog. If you stab the throttle it will bogg and backfire or die completely.

I deleted the swirl filter and went to an Earl's inline filter. The filter on the fuel pump was pretty buggered to I cleaned that out too. I pulled the injector and ran cleaner though that and it appears to be spraying alright running off the fuel pump on the quad. I opened up the FPR casing and took a peek in there and it was quite clean.

I have tried using the factory map and had no change so I put the map back in it that suite the mods I have.

So at this point the fuel system is clean. Has the pc3 tune that should be in there. Wiped out the little bit of gunk in the throttle body. And everything seems to be working as it should but the problem continues.

So then I loosen the TPS to move it to see if there is any change. When I move it the idle will change but the throttle response stays the same. I would assume since the idle changes and how easy or not easy it starts when moving it that it's working although I have not checked it with a meter nor set it back to where its supposed to be. I need to set up some probes so I can test that on my own.

I have little to no cash to spend at the moment so I cant just start throwing parts at it. I'm hoping I can get some input here that will lead me to finding the problem and only buying what I need.

Side note it does look like the fuel injector was replaced with a heap one it doesn't look OEM and the numbers on it came up with nothing in Google.

The quad ran great when I got it. Regular fluid changes. Then I let it sit all winter and half of a season. When I went to run it it was hard to start and would die on the throttle if I didn't let it warm up. Then it got worse which lead me to deleting the swirl filter last year. Qnd now I'm just getting back to work on it because I would like to get it up to par this season. Take it out once or twice. And next season I have a a couple out of state trips planned so I need to get it tip top.

Any info that points me In the right direction would be much appreciated. Thanks guys.

Also I did pull the spark plug doubled checked the gap, cleaned it and put it back in. I put a new one in it while I did the swirl filter last year.
 
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#3 ·
lash the valves correctly and move on to your fuel pressure problem. Usually the exhaust valves will tighten up before the intakes do.
 
#4 ·
I recently got an ltr 2006 ran it for a while at the track after a lap the bike wud start cutting and bogging sort of misfiring but once I switch the bike of and on it runs fine. I opened the engine and replaced the complete bottom and top end did the clearances on the cylinder heads and everything was perfect jst to be sure also changed the fuel pump, water pump, oil pump and injector as well as the fuel filers but the bike is still doing the same. It's almost as of when the bike warms up it starts misfiring but as soon as I switch the bike on and off it's runs well again for about half a lap before starting to misfire again any suggestions I would be really grateful. I've also checked the fans and the wiring to the stator checked the stator and the regulator everything is fine. Any other suggestions???
 
#5 ·
I recently got an ltr 2006 ran it for a while at the track after a lap the bike wud start cutting and bogging sort of misfiring but once I switch the bike of and on it runs fine. I opened the engine and replaced the complete bottom and top end did the clearances on the cylinder heads and everything was perfect jst to be sure also changed the fuel pump, water pump, oil pump and injector as well as the fuel filers but the bike is still doing the same. It's almost as of when the bike warms up it starts misfiring but as soon as I switch the bike on and off it's runs well again for about half a lap before starting to misfire again any suggestions I would be really grateful. I've also checked the fans and the wiring to the stator checked the stator and the regulator everything is fine. Any other suggestions???
 
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