Honda ATV Forum banner

81 - 99 of 99 Posts

·
Registered
Joined
·
110 Posts
Discussion Starter #81
Major Update!

@shadetree @Goober

Good News:
Used FCU from Fleabay arrived and was cleaned-up and installed. BOOM => Oil Temp Light working again!!!! :grin

Not-so Good news:
New OEM CDI arrived from RockeyMountainATV - did not impact "throttle issue" / "misfire issue". Issue persists.

Now waiting for the fuel pump to arrive tomorrow or Friday and will provide an update then!

Thanks for the troubleshooting help @shadetree regarding the FCU!
 

·
Super Moderator
Joined
·
36,410 Posts
if you can some how fill the carb up manually , get it cranked, see if it will top out then without any issues ?, if so ?, then I think it is a fuel delivery issue ?. either fuel pump ?, or fuel cut-off relay ?. you did buy and install the CORRECT year c.d.i right ?.
 

·
Registered
Joined
·
110 Posts
Discussion Starter #83
if you can some how fill the carb up manually , get it cranked, see if it will top out then without any issues ?, if so ?, then I think it is a fuel delivery issue ?. either fuel pump ?, or fuel cut-off relay ?. you did buy and install the CORRECT year c.d.i right ?.
I definitely did buy the right OEM CDI for that exact year. Performance was the same from the new one to the original, so CDI isn't the issue.

Fuel pump arrives today at some point (allegedly) so I'll swap it and inform the results. Fingers crossed. If that fails, it's the Carb!
 

·
Super Moderator
Joined
·
36,410 Posts
if you can some how fill the carb up manually , get it cranked, see if it will top out then without any issues ?, if so ?, then I think it is a fuel delivery issue ?. either fuel pump ?, or fuel cut-off relay ?. you did buy and install the CORRECT year c.d.i right ?.
I definitely did buy the right OEM CDI for that exact year. Performance was the same from the new one to the original, so CDI isn't the issue.

Fuel pump arrives today at some point (allegedly) so I'll swap it and inform the results. Fingers crossed. If that fails, it's the Carb!
while your waiting on the pump, get a old oil can that has a pump lever ( very handy for testing engines and carbs ! ), fill the carb up, crank it, see if it will top out in rev's ?. if it does this way ?, then yeah, its a fuel issue ?, or carb issue ?. just so you know ?, these atvs have metal gas tanks , which means...RUST !!. it only takes a very tiny piece of trash to mess a carb up !.
 

·
Registered
Joined
·
110 Posts
Discussion Starter #85
while your waiting on the pump, get a old oil can that has a pump lever ( very handy for testing engines and carbs ! ), fill the carb up, crank it, see if it will top out in rev's ?. if it does this way ?, then yeah, its a fuel issue ?, or carb issue ?. just so you know ?, these atvs have metal gas tanks , which means...RUST !!. it only takes a very tiny piece of trash to mess a carb up !.
I don't have one of those unfortunately, but I will do the swap ASAP and we should know regardless.

You put in a plastic fuel tank, right? That's not Honda OEM @shadetree lol I'm surprised! I can order a new factory fuel tank I believe still from Rocky Mountain ATV but it's super expensive.
 

·
Super Moderator
Joined
·
36,410 Posts
while your waiting on the pump, get a old oil can that has a pump lever ( very handy for testing engines and carbs ! ), fill the carb up, crank it, see if it will top out in rev's ?. if it does this way ?, then yeah, its a fuel issue ?, or carb issue ?. just so you know ?, these atvs have metal gas tanks , which means...RUST !!. it only takes a very tiny piece of trash to mess a carb up !.
I don't have one of those unfortunately, but I will do the swap ASAP and we should know regardless.

You put in a plastic fuel tank, right? That's not Honda OEM @shadetree lol I'm surprised! I can order a new factory fuel tank I believe still from Rocky Mountain ATV but it's super expensive.
no you can't buy a new oem tank from honda...they are discontinued !!!. I went with a plastic tank, thats about as close to oem as you will ever get !.
 

·
Super Moderator
Joined
·
36,410 Posts
wellllllllll..i stand corrected !.. rmatv does show a oem tank ?..welp..they did not show them 10 years ago !..lol. they were discontinued back then. anywayyyyyyyy..plastic does not rust..ever !!..and I got it cheaper than oem metal tank.
 

·
Super Moderator
Joined
·
36,410 Posts
before you place an order for a oem fuel tank ?, I WOULD CALL THEM TO MAKE SURE THEY CAN SELL YOU ONE ?!!..cuz I know for a fact..( years ago ) they were discontinued back then !!.
 

·
Registered
Joined
·
110 Posts
Discussion Starter #89
Crap!

Update:
  • Fuel cut-off relay swapped - no change
  • Fuel pump swapped - no change
  • Fuel tank drained and replaced with 93 Octane from BP + Seafoam as recommended (1oz / gal)
  • Carburetor cleaned and pilot screw set to 1 1/2 turns as instructed. Noticed that pilot screw o-ring was a little worn but probably still fine.
  • Started it and she was dying right away (as the manual alluded that it would) so I increased throttle at the handlebar adjuster until she idled
  • Tried like hell to find a way to follow the guide and slowly turn the pilot-screw in until it died, but without a special tool - not possible
  • Ended up taking the carb out and making various turns, putting it back in and seeing what happened. This apparently doesn't work, as all it does it make the engine run lean as hell, but she kept on running even when I put her in a full turn and it was only at 0.5 turns (approximately). When I pulled the carb after that (in order to adjust it the next time), white smoke came out of the engine inlet.
  • After talking to @shadetree, I turned it back in completely so it lightly seated and then turned it out 2.5 turns. Started it up (it was idling way too high), idled her down at the handle bars - and boom, still has the same issues
  • From 0-WOT in a quick impulse (gunning it), she dies right away. Gradually, she eats it up, no problem. After she died this time, I did find it interesting that I heard the fuel pump buzzing away for a few seconds
What gives folks? @shadetree @Goober ?

the only thing I see I could have done differently is take the throttle out at the handlebars and use the throttle screw so I could be sure that it's 100% consistent ... but that's about it. Not sure that's going to make the difference.
 

·
Super Moderator
Joined
·
36,410 Posts
you don't adjust the idle at the handle bars !. you set the idle at the carb with the black knob bro.
 

·
Super Moderator
Joined
·
36,410 Posts
pump buzzing like crazy for a few sec's ?..this tells me its not getting constant fuel from the tank for some reason ?. maybe clogged pick up lines in tank ?.
 

·
Super Moderator
Joined
·
36,410 Posts
think of it this way. at a slow increase with throttle to high rev, it does good...right ?, but from a dead idle to straight to high rev's, it wants to die ?. this tells me its not drawing enough fuel at wide open, and shutting down when it cant pick up enough fuel from the carb.. why ?..I don't know ?. but I know this..something is wrong here for sure.
 

·
Super Moderator
Joined
·
36,410 Posts
just in case you dont know ?, the adjustment on the bars at the throttle are only for one thing ?, its to adjust the throttle cable slack, for response time in other words, its not for idle !.
 

·
Registered
Joined
·
110 Posts
Discussion Starter #94
Tomorrow I can repeat the process with the idle using the idle screw (which I should have done to begin with but wasn't thinking, probably due to the fuel fumes lol)....

But still, with the hoses blown out, tank drained, Carb cleaned, new pump, cut off relay, and CDI ... same issue? Seems insane @shadetree.

I'm starting to think the pilot screw has nothing to do with it. I did order a new gasket set though to replace that O-Ring that's wearing .
 

·
Super Moderator
Joined
·
36,410 Posts
Tomorrow I can repeat the process with the idle using the idle screw (which I should have done to begin with but wasn't thinking, probably due to the fuel fumes lol)....

But still, with the hoses blown out, tank drained, Carb cleaned, new pump, cut off relay, and CDI ... same issue? Seems insane @shadetree.

I'm starting to think the pilot screw has nothing to do with it. I did order a new gasket set though to replace that O-Ring that's wearing .
if all else fails ?, my money says the timing is off !!!!.
 

·
Registered
Joined
·
110 Posts
Discussion Starter #96
if all else fails ?, my money says the timing is off !!!!.
Timing is fine per the manual. As a proof positive, if it wasn't, it wouldn't run at WOT when gradually gassed up there.

Keep in mind before I cleaned the Carb and changed fuel, I could get it OCCASIONALLY to take an impulse from 0-WOT. When it worked, it spit out black smoke (probably running too rich), but then it would die all of a sudden on the next impulse.

It honestly might be the pilot setting and getting it to run the right air/fuel mixture. Perhaps if it's running too rich, it actually may be flooding the engine which causes it to die.
 

·
Super Moderator
Joined
·
36,410 Posts
if all else fails ?, my money says the timing is off !!!!.
Timing is fine per the manual. As a proof positive, if it wasn't, it wouldn't run at WOT when gradually gassed up there.

Keep in mind before I cleaned the Carb and changed fuel, I could get it OCCASIONALLY to take an impulse from 0-WOT. When it worked, it spit out black smoke (probably running too rich), but then it would die all of a sudden on the next impulse.

It honestly might be the pilot setting and getting it to run the right air/fuel mixture. Perhaps if it's running too rich, it actually may be flooding the engine which causes it to die.
not really. i'd really like to know what all is going on with all the timing marks ?. the dashes/lines on cam sprocket, as well as T mark on flywheel, then I will agree..lol. these models will run even with the timing off !. if the cam is off by say..1/2 tooth ?, this will effect the compression..or in other words, the timing. its an '87 model..soooooooooo..unless you replaced the cam chain lately ?, and set the timing right ?, then I say the timing is off.
 

·
Premium Member
Joined
·
3,311 Posts
@TRX350D i know we discussed your throttle cable positioning method. But you seem to think you have it right. The results are suspicious, you know.

The pump ticking afterward suggests lack of fuel flow or air in the lines. I replaced my fuel lines because the ends were all cracked–i found good used OEM fuel lines. Pull your petcock and look into the back–has the seal become dislodged?
https://www.hondaatvforums.net/forums/honda-fourtrax/123858-petcock-rebuild-iii-86-89-trx350.html

Take and old brake choke throttle cable and cut off the end—run it into the fuel tank pickup lines just to make sure they’re clear—only about 12-14 inches—careful there are fine mesh screens at the end of those tubes.

You can check the timing chain slack–I wouldn’t do it yet. Until you get the carb replaced and set properly.
 

·
Registered
Joined
·
355 Posts
Sounds to me like the carb may need to be cleaned again. I know Shade fixed it up for you but if you connected it to an older fuel pump it easily could have put trash back into the carb. I had to repeatedly clean one of my carbs before I realized what was going on. Fuel filter is inline before the pump, so if there's trash in the pump it can't help.
 
81 - 99 of 99 Posts
About this Discussion
98 Replies
5 Participants
Duck0fDeath
Honda ATV Forum
We’re a forum community dedicated to Honda ATV owners & enthusiasts. Come join the discussion about upgrades and reliability for your Rancher, Foreman, Recon, FourTrax, Pioneer, and more!
Full Forum Listing
Top