Cadimman

iTrader: (41)

My buddy has a REVO with RB TM523. It is very new and hardly broken in with alot of pinch. I'm having trouble tuning it for him. It seems inconsistent; rich, then lean. Definitely rich at top end as RPM is a little low and piles of smoke. WOT from stop usually lean bog (no smoke). If I lean out HSN it gets really lean right away to where it has zero power. I did a quick leak test (best I could do with it bolted in truck) and no leaks found anywhere on carb or backplate. Definitely fresh fuel. Tried OS P3 and P7 plugs. RB plug is listed for application, but don't have one (I don't think; the plug I first took out of it possibly has a "6" on it but hard to tell). Different air filter. Shortened fuel line. I read on line factory settings HSN 6 turns out, LSN 5 turns out. I'm usually quite good with engine tuning, but seem way off the mark on this one.

kgombe

iTrader: (13)

take it out the truck and put another engine in there.. thats the only fix... those engines have a terrible left turn lean bog.. then when you turn right it goes rich... sorry but your buddy bought a lemon... good luck trying to fix it... now if you wanna drag race in a straight line.. then you are good

Cadimman

iTrader: (41)

Maybe so, but this is in a straight line. Up and down my street trying to get is tuned so no turning even involved yet.

kgombe

iTrader: (13)

well i you got a leak somewhere... most likely front bearing.. they were also known for its inferior quality

Cadimman

iTrader: (41)

Only one person chimes in and states this motor is crap. How discouraging. I'v known the 728 and 928 and ws7 line to be incredible engines. I find it hard to beleive this one is just a paperweight.

When I get a chance, I'll leak test the engine out of the truck, but don't beleive it's just a junk engine. Any other opinions ideas here?

kgombe

iTrader: (13)

sorry man.... hope someone can help you out

Cadimman

iTrader: (41)

Doesn't look like anyone will/can.

jpalessi

iTrader: (55)

i had one of those YEARS ago when they first came out, and they were junk then. honestly your better off with the traxxas engine, or a OS TM/TZ

As for getting it tuned the right plug is always a great start.

Felix

iTrader: (9)

There is no fix they are turds...

Cadimman

iTrader: (41)

Well I've heard it from 3 people now.

Thanks.

geejay

iTrader: (1)

had one - loved it - no problems

your lean bog is because must adjust a the throttle points , each engine is different. the bog is probably caused by chassis flex while turning.

The problem is that RB are not easy to tune, especially if your new to the hobby.

You need to fully break it in before you start drastically tuning it.

Take your time and set the EPA and Trim to the correct position.

Chris Peralta

I ran one of these several years ago and never had the problem with it leaning out when turning a certain direction. These engines are not Nova based engines like most RB's. These are Sirio based motors that were made my Star Motor so the carb isn't going to tune like RB's/Novas most are used to. Try to richen the LSN (raise the idle when you richen the LSN) and then try to set the HSN so it runs good at high speed. I do remember the carb is very sensitive and you need to make very small turns.

Cadimman

iTrader: (41)

Thanks for the advice. It's not fully broken in yet. EPA and trim is beautiful. Definitely not new to the hobby (that's why I'm a little confused). Not doing any turning yet, so chassis flex not an issue.

Thanks also for your advice. Did not know it was Sirio based. I used to have to tweak my Sirio 18 alot. Maybe their carbs are sensitive. What I'm finding odd (made me think of air leak) was if I "roll" on the throttle, top end is too rich; piles of smoke and lack of RPM and sounds like four cycling. But from a stop if I pull WOT it's a lean bog; no smoke and just about dies. We'll run some more fuel through it and retune. Found should be 6 turns out on HSN and 5 turns out on LSN. Also the plug listed is a "medium". Don't have an RB plug, so tried the OS. Seems to like the P3 better than P7.

geejay

iTrader: (1)

CPs the man................

Madbrad

iTrader: (30)

Check your idle gap too if you havent already, i've had that cause me problems before too. You said the motor was new but you may want to check the carb o-ring just so you know they are good. I wouldnt give up on it yet, i think people give up too easy and just say that there "crap engines" and take the easy way out.