my4ari

iTrader: (2)

Hi everyone,

I am looking for some possible solutions to my problem. I have a brand new run in Argus R8 which yesterday I had all sorts of issues with it bogging - but only after about 8 mins of running.

We tuned the engine prior to each run due to the bogging issue, but in each heat, with around 2 mins to go, the engine would start bogging out of corners and become very hard to drive. It would not die though not matter how long you let it sit for. The only way to make it better was to go rich on both low and high end needles - we found going at least 4 hours on each was the only way to get it driveable.

What would be causing this? Could it be fuel related as my wifes engine was also hard to get tuned all day with similar bogging issues - only hers were nowhere near as bad as mine.

I replaced the entire fuel line halfway during the day - the exhaust seals are both newish (1 race day old) and same with the glow plug.

Any help welcomed. Engine ran awesome for most of all of the races until futher on through each heat.

Jaz240

iTrader: (52)

Check your clutch. Most times when an engine just starts bogging "all of a sudden" your clutch springs or shoes are the issue.

Keith Lewis

iTrader: (16)

Sounds like you already know the solution as it would only run right when you richened the LSN and HSN.

I used to have an Argus and it was very cold natured and if it was not preheated well it would be very rich the first few minutes of running. I have had to richen the LSN after heats also because I would lean the LSN before hitting the track because it sounded very fat on the box. I quickly learned to leave it alone and let it warm up properly before and while on the track. My Argus always performed better with a richer than usual LSN.

jpalessi

iTrader: (55)

bogging out of the corner is usually the HSN being too lean. I would suggest fattening the hsn, lower the idle, and leaning the lsn if need be.

my4ari

iTrader: (2)

Thanks for the replies guys. Only problem with going richer from the start is that we found it bogs if too rich - hence setting the needles leaner - but then as the engine gets hot, it then bogs.

I wondered if there might be an air leak somewhere or bad fuel - but from what you guys are saying, I just need to try and get it running richer than normal and go from there.

packerbacker

iTrader: (4)

What kind of plug are you running? It is definitely to lean if you are getting a bog issue.

t0p_sh0tta

iTrader: (35)

I agree with JP, get the idle gap straightened out, and re-tune. I was overly cautions yesterday and went too fat on the the top. I had good snap coming out of the corners, but it fell on it's face half way down the straight.

edit: Is the engine up to temp before you start tunring needles? It HAS to be hot before tuning. Sounds like you could be tuning too early, and it leans out as it comes up to temp. How long were these races?

Maximo

iTrader: (11)

what clutch are you using ?

nv529

iTrader: (53)

How old if your fuel?

my4ari

iTrader: (2)

Brand new fuel on raceday. Sidewinder 25%

Clutch im using is a standard 3 shoe JQ clutch - which could be one of the causes as I have used these clutches before and find the shoes wear really quick.

As for tuning when cold - no the engine is pre-heated before each run using RC Surestart engine heater so always tune when hot not cold.

The plug is OS P3 plug.

Tonight im going to put all the needles back to factory settings and start tune from scratch again, but prior to that im going to check everything to make sure there are no air leaks anywhere.

george919

iTrader: (3)

Defiantly check for air leaks specifically the front bearing, backplate, head, and carb basically all of it. I've had major problems with my engines just because my head wasn't tightened properly.

wmazz

iTrader: (1)

I am by no means here, but because you can't solve your problem with fuel screw settings, maybe
your engine is getting heat-soaked.

If that is the case, perhaps your gearing, or some part of your set-up is to aggressive for your new
engine, and it is unable to dissipate its heat after it has been running for some period of time. It might
be a good idea to start with smaller pinion gears and less nitro, until you find a good set-up. Then
improve upon that set-up.

Whenever I start tuning on a new engine, I always start cautiously, and my gearing is always
slower than normal.

Jaz240

iTrader: (52)

I still think the whole issue is the clutch. Sounds like its heating up which will cause issues with the springs. (They get softer when hot) soft springs and worn shoes will definitely start bogging on you. Put a good 4 shoe set up on that puppy and let her eat!

wmazz

iTrader: (1)

What you are saying is the clutch may be engaging too soon, or the clutch may not
be disengaging. Either may cause the engine to heat up and loose power.

If the clutch is in good condition, is it possible his engine requires a different clutch
set-up for his new engine. Because the engine produces more power, but at a higher
rpm.

my4ari

iTrader: (2)

Ok so an update. Have checked everything for air leaks and the only thing that showed any sign of a leak was the front bearing - I was going to replace it but read on here and a few other sites that this is common and not an issue.

I have replaced the exhaust gasket in the muffler as this looked a bit worn, and replaced the clutch with some brand new shoes (have ordered a 4 shoe clutch kit just waiting for it to come in stock from local supplier)

Pulled entire engine apart and cleaned it. When I took the head off, the top of the piston was black!! what does this mean?