[floger70]

hey guys. new to this forum. ive tried a bunch of other forums and havnt found the issue yet so im trying here to.

2007 honda trx450er
aftermarket parts:
slip on pipe
big bore kit
stage 2 hot cam
r&d quick jet kit
air box lid cut open and put lizard skin top on it
k&n filter


heres the problem
when i start the bike, it idles fine no problems at all running smooth. i can give it quick shots of the throttle and it revs up and down like a normal bike no problems. when i try to ease into the throttle to slowly accelorate at all the bike bogs and shuts off. if i push the throttle wide open and hold it it revs up then bogs and shuts off.

i have tried the following to fix this.
tried these main jets, 130,135,155,162,188. the slow jet is a 45 and leak jet is stock.

tried moving the clip on the float needle to every spot on it.

i have tried every setting i can set it to on the fuel screw. from all the way in to all the way out and everything in between. tried moving the accelorator pump screw in and out and everything in between. still nothing. does the same thing for any of these settings.

also i bought a dyno jet kit and tried that with the new needle and jets and set those accordingly and still the same thing.. im running out of options and cannot figure it out. below i will post a pic of the carb with the quickjet and a video of it running and what its doing.

thanks
brett

 

[90vfradam]

When did it start doing this?? before or after a mod??

 

[floger70]

sorry i should have mentioned that. i bought the bike about a month ago with all the mods done to it as is. it came with the 155 jet in it and then i tried everything else on it.

 

[Here 2 help]

Your problem appears to be in the throttle position switch in the throttle housing. I am guessing that when you ease into the throttle the ignition loses spark. This can be verified with a timing light. If you lose spark as you ease into the throttle, try adjusting the free play in the throttle cable. If adjustment fails to solve the problem, try unplugging the switch from the wiring harness (it will solve the problem or it will not start and run at all). Last try, the throttle position sensor on the carb. It can be tested with an ohm meter. I don't recall ever seeing one fail, but inexperienced mechanics can damage the unit or set it improperly.

Let me know if this helps.

 

[floger70]

when i unplug that the bike shuts off. there is no free play in the throttle cable at all. im going to check the ohms on the tps tonight and see what it is

 

[Here 2 help]

Honda specifies about 1/4 inch of free play on the thumb lever. no freeplay might be the cause of the problem?

 

[floger70]

hmm. ill have to see and try that. i checked the tps sensor. bike off between pink wire and yellow and green wire it was 5 ohms on the 20k setting. i belive this is right where i want to be. ill try that adjustment on the throttle cable though

 

[trx2fiveO]

measure the resistance between the pink and green/yellow wire on the sensor side of the connector. (unplug it)

Standard : 4-6 ohm at 68'F

Calculate the throttle position resistance at idle speed.
A x (0.13 - .015)= B
A= pink and green/yellow wire resistance
B= Throttle position (light green - Green/yellow) resistance at idle

EXAMPLE: if the pink and green/yellow terminal resistance is 5 kohms then throttle positionsensor light green- green/yellow resistance at idle speed is: 5kohm X (0.13 -0.15) = 650 - 750 ohms

Adjust the TPS so the resistance between the terminals (light green and green/yellow) is at what you calculated from the above equasion.

If this don't solve your issue then there is an issue with your Closed throttle position detection system. Which that is an ignition cut-off system that will prevent the engine from running at any speed beyond Idle while the throttle lever is closed, just incase the throttle drum sticks so to speak. I think your TPS is bad personally but it could be that also. Check for a bad micro switch at the throttle. Good luck

 

[floger70]

okay great thanks. ill have to try reading it at idle and see if its right in that area. how do you go about adjusting it if it isnt?

 

[trx2fiveO]

IF you have to adjust the TPS you simply loosen it and turn it leave your meter connected so you can get the proper reading.

 

[floger70]

okay great. thanks. ill give that a try

 

[floger70]

so i just tested it and all the numbers are bang on its still doing the same thing. anthing else i can try/ test??

 

[trx2fiveO]

CHeck your accelorator pump on the bottom of the carb. after listening to your video again it sounds like a quad I just replaced the accellerator pump on for the same issue. it's quite possible you have trash in one of the orfices too.

 

[floger70]

it has been checked and is working fine. adjusted it in every possible setting and still no change. also adjusted the free play in the throttle lever to 5mm and still no difference

 

[trx2fiveO]

Ok Working properly and having a bad spot on the diaphram are not the same, I'm not trying to be difficult just trying to help out.
Have you bypassed the carb switch? the green wire and the Pink/blue wire?
Does the engine do the same cold as it does hot?
Have you bypassed the throttle lever switch? Gray/red and Green

 

[floger70]

i dont find you to be difficult haha any help is great.

engine does the same when hot or cold. doesnt matter.
havnt bypassed with switch. and i dont think there is anything wrong with the diaphragm. its been looked at quite thoroughly.

should i try bypassing one or the other switches and how would you recommend going about that.

thanks
brett

 

[trx2fiveO]

you can take a wire with alligator clips on each end and jump between the two wires on each of the two switches I mentioned that should do the trick. keep me posted.

 

[floger70]

okay ill give that a try and see if it makes any difference. i know when i unplug the carb one the big dies but thats it. ill give it a try this week when i can

 

[trx2fiveO]

don't mistake the carb switch for the TPS on the carb , I'm not 100% sure where it's located but it may be like on the base???

 

[floger70]

yea. the tps sensor is the black sensor on the left side of the carb. it bolts on and is adjustable. the carb switch is located on the right side under the black cover. its right where the idle control and the throttle cable mechanism is. i have a service manual of where everything is just cant seem to get the stupid thing to work right. i never had a chance to try jumping the carb switch and the throttle lever switch yet. probably gonna be Wednesday before i can. ill post on here when i do and see how it goes.

thanks
brett