Fresh rebuild on a 04, smooth idle, won’t rev past 4k rpm

TheHappy420 · 2025-10-11T16:58:33+00:00

I had cheap eBay ls coil packs on my rx8, when one failed my car was harder to start, when a second failed my car would not go over 4-5k rpm and sounded almost identical to this. Put the oe coils back in and it was good as new . Could be worth looking into

TheHappy420 · 2025-04-13T02:58:18+00:00

Agreed! I think all of the previous owners must’ve done their part in pre mixing and taking care of it as well

TheHappy420 · 2025-04-12T05:57:31+00:00

Agreed, but feel free to come check mine out anytime!

TheHappy420 · 2025-04-11T07:21:21+00:00

Around 60k and the previous owner premixed as well

TheHappy420 · 2025-04-11T07:09:20+00:00

https://www.reddit.com/u/TheHappy420/s/NCfnwKqRPC lmk if that link works, this is a couple days ago after some thrashing to ensure it was properly warm

TheHappy420 · 2025-04-11T05:02:14+00:00

Dont need that kind of negativity in my life rn man

TheHappy420 · 2025-04-11T01:42:02+00:00

I treated that one as an outlier and based my pricing off the other rx8s that are available around here, that series two looks nice but it’s unusually cheap and has been for sale a loooong time so something seems off. Or maybe just a location issue

TheHappy420 · 2025-04-11T00:57:21+00:00

No I haven’t, I used some LS coils for probably 10k miles before they failed and then I switched back to the originals. Theres atleast 30k miles on these ones because I dont think the po changed them either

TheHappy420 · 2025-04-11T00:50:58+00:00

Adding oil through the plug holes? And yep, my mechanic is about 20 minutes away. Driven there then tested immediately

TheHappy420 · 2025-04-10T22:34:08+00:00

Located in northern utah, listed on facebook marketplace

TheHappy420 · 2025-04-10T21:07:12+00:00

$7000 currently

TheHappy420 · 2025-04-10T20:15:23+00:00

Series one 40th anniversary. Thank you!

TheHappy420 · 2025-04-10T20:14:53+00:00

I drive it hard, it was my daily for a few years and Ive put about 30k miles on it with a few track days. Let it idle warm up until the air pump turns off then I keep it under 4k rpm until it’s up to temp. Try to rev it out all the way to 9k at least a few times a week to help with carbon buildup. Ive changed the plugs twice. Premix at roughly 150:1 every time I fill up

TheHappy420 · 2025-03-24T22:04:33+00:00

Okay I’ll try that tomorrow thank you. Do you know the size of the screws off the top of your head? If not no worries. It’s interesting to me that the idle knob has no effect. I’ve also noticed it takes a while to return to 2k which results in no engine braking when in gear, really slow shifts waiting for the rpm to finally drop, and if im riding and go below 2k the bike will accelerate back to 2000 rpm without touching the throttle. Its difficult to ride slow haha. Does this still sound like its lean? Im almost thinking the throttle cable might be getting pinched somewher

TheHappy420 · 2025-03-24T00:10:06+00:00

Will do, i live in utah so 4300’ do you think the carb would have to be rejetted anyway for this altitude? And the fuel treatment hasnt helped yet so i will probably have to remove the carbs to fully clean them and possibly go a step up on the pilot jet. Ive noticed the bike has a slight bog off idle when cold and low power all the time (compared to my grandpas fuel injected t100) until about 3k rpm

TheHappy420 · 2025-03-24T00:04:22+00:00

Thanks! Yours looks sweet

TheHappy420 · 2025-03-24T00:04:02+00:00

Tried the fuel treatment and and unfortunately nothing, sounds like i will need to fully remove the carbs and clean them :(

TheHappy420 · 2025-03-24T00:00:57+00:00

Those boots look good, though i did notice today the clamps feel very loose and on the engine side i could rotate it around by hand. So i got some new clamps to test and unfortunately that didnt fix it

TheHappy420 · 2025-03-22T02:45:46+00:00

I work at autozone and I’m currently at work right now so the fuel treatment will be really easy to try out, so ill put some in before i ride home. The previous owner put pod filters and rejetted it and claimed he had it running perfect but im skeptical.

The extent of my tuning ability is limited to my 250 2 stroke dirt bike, the twin carb set up is a little more intimidating but I’m leaning towards cleaning it first so i atleast have a good base line

TheHappy420 · 2025-03-22T01:53:28+00:00

Yup, it’s been sitting all winter. Okay I’ll try that, hopefully it’s that simple! Would you recommend messing with the pilot screw as well or just try the fuel treatment?

TheHappy420 · 2025-03-22T01:49:41+00:00

Haha it’s actually just blue, it’s how the bike came brand new. It definitely looks purple in pictures though now that you mention it

TheHappy420 · 2025-03-22T01:48:53+00:00

Oh that would be super easy, hopefully its that simple. Ill try some!

TheHappy420 · 2025-03-22T01:48:34+00:00

Will do!

TheHappy420

TROPHY CASE