Help!!

[Nitroaddict]

Okay - Last week, i seemed to be having some engine problems towards the end of a bashing day with the RZ(VO1B). Figured it was nothing, so i took it home. The problem was that it seemed to be running excessivly rich at idle. When home, i took the carb apart and cleaned everything, made sure nothing was damaged, and put it all back together. reset the needles to 2 1/2 turns out for the HSN, and 1 1/2 turn in from flush for the LSN. Now, when i started it up, same problem. As long as I'm running, plenty of power, a bit rich on the HSN, but not too bad. come down to slow speeds though, and no acceleration. Bogs down like the LSN is too rich, and at idle it will stall. Through continued tests, i have now leaned the LSN an additional 2 full turns, with no change in engine behavior. Still stalls at idle, still sounds super rich. any ideas?

 

[RobH]

Did you remove your needles and check that the O-rings are ok and that the tip of the niddles aren't nicked or something? I'm just graspings at straws. I've never had that problem. FlyingRazorBack is a pro with that engine. Maybe he can offer some advice.

Good Luck,
Rob

 

[Nitroaddict]

Rob - I did a quick check and everything seemed okay when i took it apart the other night. maybe i should tear it down again, and do an inspection with a magnifying glass or something. not sure about what is causing the problem, since i hvnt ever seen this issue before either. Possible air leak? not sure, as that usually causes flucuating lean conditions.

driving me nutz. weird thing, is that normally, if the LSN was super rich, u could just open the ISS until the engine would stay running at idle, even if it took the carb opened 50% to work. However, no matter how much i open the carb, it wont stay running, unless i continuously blip the throttle. This is driving me nutz, any help would be appreciated.

 

[FlyinRazorback]

Are the cb bearings in good shape? What about the shoes and springs? You're issue may be in there.

Just some other things to consider.......

Take your lsn all the way in and back it out 3.5 turns. I always liked to set it that way. That way you know exactly how far out the lsn is. Remember to open your carb all the way when turning your LSN.

What type of plug are you using? Have you tried a different plug? Just b/c it glows doesn't mean that it's still good. The O'donnell 99 and OS 8 are the best plugs for that engine.

I would probably replace all the fuel lines if you haven't done so recently. If you have a fuel filter, check it out. I had an engine run really strange on me and turned out it was a fuel filter problem.

One more thing, how new/old is the engine? What is it temping at and how does it act when giving throttle? Is it just shutting off when applying brake?

 

[Nitroaddict]

FRB - I will reset the needles according to your recommendations and check that out. i didnt look at the clutch bell because it doesn't feel like a clutch problem. The fuel filter is fine, i checked, as is the air filter. doesn't stall when i hit the brakes, only if it idles for more than say 2-3 seconds. so if i am running at a good clip, and then hit the brakes, it will usually stall by the time i come to a stop. As for the Plug, that is a good point. I changed plugs recently, wonder id maybe that has something to do with it. doesn't act like a plug problem, but could be. It started doing this shortly after the plug change. I will try out.

 

[RobH]

could the spray bar be messed up? I don't know how that carb works, but on the OS carb on my 8-port the spray bar is static and the LSN moves in anf out of it. That carb is a complete different beast, however, and only has 2-needles. If a chip came off the spray bar or something got wacked, it wouldn't run very well at all.

What's the OS # for that carb? A friend of mine may have a used one laying around that he could sell you cheap.

-Rob

 

[Nitroaddict]

it is the 20B carb, rob

 

[FlyinRazorback]

Well, I was just troubleshooting at some of the possibilities. How much fuel has the engine seen and how many gallon(s) has the clutch seen? Keep us informed.

 

[Nitroaddict]

clutch is about a gallon old. engine had the piston/sleeve/conrod replaced about 3/4 gallon ago. carb was rebuilt with new o rings and gaskets about 1/2 gallon ago. basically a new engine.

 

[RobH]

I talked to Ed on the phone for ya. He said it might be the carb and does have one used but it's well... been used and not worth much. He seems to think it might be the clutch more than the carb. His advice is to to change out the clutch springs every gallon or so.

This may not help you from the sounds of it, but Ed's advice on getting the LSN in the ball park is as follows: open the ISS to 1mm and then adjust idel with your LSN (when it's warm and cleared out). It won't be exact, but it'll get you close. I personally like my RC's to idle for no more than 15-20 seconds before they load-up and die (just me though).

Anyway, if you want to email him and maybe get a cheap extra carb for testing purposes. His address is [email protected]

Good Luck,
Rob

 

[Nitroaddict]

hmm. i will check the clutch this weekend, and see if that could be the problem.

 

[Nitroaddict]

well, i checked out the clutch bell, and all seems well. Also, i assume that the only reason a clutch will cause this problem, is if its engaging too early, it will create a load on the engine at idle. If i leave the buggy on the starter box while running, if the clutchbell is bad, the wheels should move at idle. they do not. i still can't seem to figure this problem out, and wanted to run it this weekend. any more ideas?

 

[StrechM]

Your decription sounds like a carb issue after ruling out the clutch spings. I'd take it apart again and inpsect it.

 

[Nitroaddict]

stretch, thats the problem - I've taken it apart twice already. i see nothing wrong. arrggg! lol. I'm missing something, just can't figure out what it is.

 

[StrechM]

I wish that I was a guru. The only problem that I have had resembling your issue was a worn out clutch spring engaging to soon on my old T Maxx. I'll copy your post and forward to my lsh if that's ok. There's a gent. over there that runs the OS prducts and maybe he will know.

 

[mcvickj]

Did you try posting on RCTech.Net or RCU. What about asking any of the guys at your LHS?

 

[Nitroaddict]

i havnt talked to anyone at my LHS, mcvickj. U get one guess if i posted it at RCU, lol. I havnt posted it at RCtech, but will now.

Stretch - please contact ur lhs, that would be appreciated.

 

[StrechM]

NA, my lhs says sounds like the carb.

 

[Nitroaddict]

thanks stretch. I got it running this weekend, but still had problems. I am looking to just replace the engine, since its old anyways, and use this one as a backup.