TRX250R.ORG
Workshop => Carburetor, Intake, and Exhaust => Topic started by: Bowtie316 on October 10, 2013, 09:53:08 PM
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This is cross posted, I just wanted to get some more opinions on it.
So I put this new motor on my bike and it just doesn't want to clean out and run. Plug chop still looks good but just seems like too small of a jet. My combination is below and today I started at 190 and tried 188, 185, 182, 180, 178, 175, 172, 170 and then back and tried 190 again, it was definitely too rich, tried running 180 again with the air filter off, no change. It runs great on the midrange with a DGH needle on 3rd clip, but once on the Main it just won't clean out. Do I need to go leaner than 170? It feels like it pulls better in 5th and 6th gear than the first 4.
It was low-mid 80s today, I'm at about 900ft of elevation, running Sonoco 110 with 927 at 32:1.
ESR 330 ported by K&T
4 mil stroke hot rods crank
Trx5 pipe and silencer
38 A/S carb, K&N filter, no airbox lid
Boyesen rad valve, carbon reeds
Here are the plugs from the 170 and 180 runs, the 170 had more run time on it than the 180.
(http://[URL=http://s851.photobucket.com/user/bowtie316/media/20131010_173507_zpse730442f.jpg.html][IMG]http://i851.photobucket.com/albums/ab73/bowtie316/20131010_173507_zpse730442f.jpg)[/URL][/IMG]
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What ignition? Sounds like a stock ignition with to much gap. If stock gap down to .018.
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How's the power? Maybe try the plug gap next..
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You also mention ride time....are these plug chops or were you riding around on them?
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What ignition? Sounds like a stock ignition with to much gap. If stock gap down to .018.
Stock ignition and Plugs are gapped at .020, I can tighten it up a little more and see. Also, this is on BR8ES, I will give a B8ES a try.
How's the power? Maybe try the plug gap next..
Runs pretty much like my 88 when it's not on the pipe, when it comes on the pipe it feels like it's going to pull real good then it just starts crapping out. It starts great and is running plenty cool, so that is all good. It is alot louder now, and that is with fresh silencer packing.
You also mention ride time....are these plug chops or were you riding around on them?
The 180 was a clean plug chop, the 170 was new plug ran with 178 down to 170. It was my last new plug. I just got a bunch of new B8ES to try. I'll close the gap down.
The more I think of it, thats probably the problem. 190 definately felt too rich but it didn't seem to improve much under 185 or so. I'll close the gap and try these new non resistor plugs. Thanks for the help.
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Be careful leaning it out if it's the ignition holding you back. You can still detonate going lean with a weak spark.
I was in the same boat trying to get my Alky motor running right on the stock ignition. Wouldn't pull on top end like it should. I swapped the coil to a Nology, changed the plug wire to a solid core non resistor wire, swapped the plug boot for a non resistor boot, and went to a non resistor small electrode plug and that helped. However I could tell it still wasn't right. Upgraded ignitions and holy crap! I needed to nearly double the fuel going in and man did it pull hard on top.
Long story short....start saving for an ignition upgrade.
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Be careful leaning it out if it's the ignition holding you back. You can still detonate going lean with a weak spark.
I was in the same boat trying to get my Alky motor running right on the stock ignition. Wouldn't pull on top end like it should. I swapped the coil to a Nology, changed the plug wire to a solid core non resistor wire, swapped the plug boot for a non resistor boot, and went to a non resistor small electrode plug and that helped. However I could tell it still wasn't right. Upgraded ignitions and holy crap! I needed to nearly double the fuel going in and man did it pull hard on top.
Long story short....start saving for an ignition upgrade.
I agree, thinking back, I don't think it really got any better after around 180 or leaner, I'm going to swap back to 185 main and try the new plug with tighter gap. I'm also going to check out all the electricals again.
If I can't get it to run right with a stator that has lighting, I will sell it and go back stock.
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I believe the Service Honda CR500 ignition kits have a provision for lighting...as opposed to selling the motor you just bought
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Thanks for pointing that out, who is service honda? Can their parts be considered as reliable as OEM?
I'm still on the fence with this motor anyway, If I could do it all over again I would opt for less port timing and less compression. Time will tell though, it might all be worth it in the end.
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http://www.servicehonda.com/hard%20parts/hard_parts_old.html Service Honda sell OEM Honda parts.
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Service honda is a great online source for oem parts. That being said the ign kit tbone is talking about is not an oem honda item. It is Electrosport or something like that. Someone else will post the correct manu.
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Be careful leaning it out if it's the ignition holding you back. You can still detonate going lean with a weak spark.
I was in the same boat trying to get my Alky motor running right on the stock ignition. Wouldn't pull on top end like it should. I swapped the coil to a Nology, changed the plug wire to a solid core non resistor wire, swapped the plug boot for a non resistor boot, and went to a non resistor small electrode plug and that helped. However I could tell it still wasn't right. Upgraded ignitions and holy crap! I needed to nearly double the fuel going in and man did it pull hard on top.
Long story short....start saving for an ignition upgrade.
whats the function of the resistor portion ?
ive got non resistor plug but i think i have resistor cap. not sure what kind of wire. heard people say ditch the resistor cap but wasnt sure if i could still use nonresistor plug inconjunction with it. mine stutters at top end also. thought it might be all jetting but im thinking now it might be some electric causing it. atleast if i got the ign sorted out then i could rule that out as a casue for the stutter and just focus on the jetting
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The resistor is to help avoid interference. In cars it helps eliminate things like engine noise in your stereo. In a quad with a simple CDI I don't believe it is needed from what I have seen and read.
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Had a chance to check some plugs and all were gapped at .028-.030, I swear I remember gapping them all at .020 so I wouldn't have to mess with it in the field. Anyway, got 10 B8ES to play with and will probably order a couple B8EGV to try out as well. Guessing and hoping that Polonda nailed it with his original diagnosis. It might be tomorrow before I get a chance to test again.
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The resistor is to help avoid interference. In cars it helps eliminate things like engine noise in your stereo. In a quad with a simple CDI I don't believe it is needed from what I have seen and read.
resistor plugs have a 5 ohm resistance built into the plug, meaning the current has more resistance to ground, ground being the block, which in theory means a weaker spark to your cylinder,
the resistor plug is best used to eliminate any "noise" caused by transient voltage, to sensitive electronics,
not really needed for any racing application that's not using an onboard computer,
unless your using a GPS or other electronic equipment, you will get a slightly better spark from a non resistor plug
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i believe most if not all bikes used some kind of resistor in the system . either at the plug or boot. is it safe to say the purpose was to eliminate any possible interference with the cdi ? at any rate i was thinking to take out all the resistors
how would i tell if i had a resistor wire ?
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Take the boot off and look at the center conductor of the wire. If it looks like standard stranded wire it is non resistor. If it is a single strand of a dark gray/black material it is resistor. Nearly all stock stock wires are resistor. I went to napa and bought a coue feet of non resister wire off a spool they had in bulk.
The stock R cap and wire are both resistor.
You can also take the plug wire out of the coil bit it may be glued in. I believe the stock R coil wire is glued in. Not sure how difficult it would be to get out.
I upgraded my stock coil to a Nology unit.
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Swapped plugs and the bike ran fine yesterday. I ended up back at a 188 main jet, it wouldn't run clean on a 190. I ended up having to go to the second clip on the DGH needle to get it to clean out around 3/4 throttle but it was running pretty good. It pulls good and hard, and is much louder and deeper sounding than with the 250cc motor.
Thanks Polonda, you hit the nail on the head.
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No problem man. Glad I could help.
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what about me?i helped too"lol".glad you got it running good.
Well, Polanda called spark plug gap right off the bat, that was the root of my problem. Then after I got that fixed and jetted it back up where it was supposed to be, then I was too rich on the needle, well atleast in the 3/4 throttle range. I am pretty sure going to the CEL needle you suggested will clear it all up.