2007 trx 400 fga valves, timing, and idle issues

731 Views 9 Replies 2 Participants Last post by Matches, Aug 29, 2018

Matches

Discussion Starter · Aug 18, 2018

Hey guys, new here! You all have helped me lots in the past, I’ve done the clutch multiple times and just did the top end this spring on the advice I seen on this forum! Thanks for that!

Now my issue, I had it running really nicely. Until one day it was sitting idle, and my valves all of a sudden starting tapping like crazy! So I brought it in, tore it down again to adjust the valves. Now, I had adjusted the valves properly with the piston on TDC and the flywheel directly on the timing mark, and they are still overly noisey. Never mind the fact that it won’t idle worth a damn and sputters when givin throttle. Any help will be appreciated! I’m at my wits end! Thanks guys!

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shadetree

· #2 · Aug 18, 2018

I moved your thread here to the repair section, the new member section is..well..for introductions , not repair cases

. sounds like you need to pull the rocker box back off, have a look. make sure the lock nuts for the valves are still tight ?. do another valve adjust, AND MAKE SURE YOUR ON THE COMPRESSION STROKE AND NOT THE EXHAUST STROKE !.

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shadetree

· #4 · Aug 21, 2018

Matches said:
shadetree said:

I moved your thread here to the repair section, the new member section is..well..for introductions , not repair cases ?. sounds like you need to pull the rocker box back off, have a look. make sure the lock nuts for the valves are still tight ?. do another valve adjust, AND MAKE SURE YOUR ON THE COMPRESSION STROKE AND NOT THE EXHAUST STROKE !.

Click to expand...

A damn I must’ve missed that! Thanks! And okay I’ll give that a try!

yw, keep us updated plz

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shadetree

· #6 · Aug 28, 2018

Matches said:
So my valves are properly timed, everything there looks good. But it wouldn’t run properly now. Choke hardly starts it, I have to put my hand partly over carb to get it running, once it’s running I have to keep the choke on. I could give it gas with choke but it sputters and almost sounds like it misses every so often. As soon as choke is off, she dies. Do you think I need a carb kit? I’m gonna try to clean the carb. See if that helps it.

my money says the timing is off. run a compression test, this will tell us a lot !.

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shadetree

· #8 · Aug 28, 2018

Matches said:
So I talked to a near by small engine mechanic and he said to “bump my timing up to .008 instead of .006.” Figured maybe valves to tight. ”If that doesnt work, pull the head off and check the valve seat. You flip it up side down and pour water on the valves with spark plug in. If water leaks out, you have a bad seat.”

So I tried the timing difference. No change. So I pulled the head off and did the experiment. And well, I guess I need new valve seats as water leaks out of my exhaust seat.

So thank you very much for your help and information! I’m really hoping to get this thing running at least before winter! ?

your suppose to use gas..NOT WATER !!..LOL. that person doesn't know what they are talking about !. NEVER..EVER..USE WATER..THIS CAUSES RUST !.

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shadetree

· #9 · Aug 28, 2018

instead of a valve seat, try lapping the seat before you go through a lot of extra work for nothing. just a FYI= you can't replace the valve seat !, it's pressed into the head. only thing you can replace is the valve guides...THATS IT !.

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