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Tired of 8 port problems

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Old 04-17-2003, 04:40 PM
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AdamB
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Default Tired of 8 port problems

Okay, I'm tired of the tuning problems I am having lately with my 8 port. Runs lean but way rich in middle. Heating up too much. But spits raw fuel and shuts off while accelerating. Runs okay at full throttle, but sucks every where else.

I bought new fuel tank, fuel lines, tore engine apart and sealed up. Anyway, even tried adjusting the factory set mid speed needle.

I think something wrong with piston and sleeve after only 1.5 gallons of fuel.

My question is, I got my eye on the new Ofna picco .26, but is this any better than the 8 port? Is the pull start any better etc.?

Should I just get new piston sleeve for 8 port, or go with picco .26 if I can find one in stock?
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Old 04-17-2003, 05:20 PM
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Default Tired of 8 port problems

Maybe the carb is defective?
Try soaking it in alcohol and see if that helps.

IF the engine responds differently at different speeds, thats a clear indication that the engine is doing ok (runs well at full throttle). If the pioston sleeve is screwed up then it'll be screwed up all across the RPm range (with exceptions I'm sure!)

-ram
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Old 04-17-2003, 05:30 PM
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Default Tired of 8 port problems

I'm not sure I'm getting full RPMs at full throttle, but does seem to respond better at higher RPMS.

I am probably getting some air leak around idle or mid throttle.

I also noticed the piston is pitted as well, indicating lean run over time.

Like I said, am getting tired of messing with this engine.

Almost would rather go back to stocker...
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Old 04-17-2003, 05:54 PM
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Default Tired of 8 port problems

when problems get that hard and you cant figure out whats going on, go to the LHS! goodluck.
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Old 04-17-2003, 08:24 PM
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Default 8 port

I have never ran the 8 port. I have the picco and it kicks butt. It has tons of power. I run a 16 t bell and it will wheelie even going about 10 mph (only if the tires hook up). It has tons of power. The way I adj. my mid range on the engines was to tune the high end, low end, then try to run the engine at about half throttle. i then check to see if it looked rich or lean and adj. from there. I then reset everything again to fine tune. Make sure that the carb is totally clean. Don't just soak it, but take it all apart and check it out. Sometimes little shavings, or what ever will get logged into the spray bar or by the needle. also check if you can the needle and needle seat and make sure there are no nicks.
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Old 04-17-2003, 08:48 PM
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Default Tired of 8 port problems

My 8 port originally did kick butt, it too would wheelie with a 16T. However, as of late it is getting to be a pain.

Basically, the engine isn't reaching full top speed, and bogs upon hard acceleration.

Sounds rich, until I do the pinch test and it shuts off right away and has incredibly high temps.

Okay, lean, I richen it up and it shuts off right away.

I also fried a couple of OS#5 plugs, I switched to OS#8 which seemed ok, last time I ran it I tried a #3 (LHS recommended). Also seemed ok, but still sputters. Although hasn't completely shut off in awhile.

While accelerating, it sputters and also shuts off sometimes, other times it'll catch and rev normally.

Probably an air leak I'm sure.

I just read somewhere that an engine that won't seal up properly w/o a lot of high temp gasket sealant isn't worth messing with.

My OS heli engines never give me this problem. Maybe I should reach a little deeper into my pocket and get a better engine.

PS I've been messing with RC nitro engines probably for at least 10 years, so am not a complete idiot.

So my original question, does the Picco .26 run any better, or is it too early to tell?
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Old 04-17-2003, 08:56 PM
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Default Tired of 8 port problems

Not putting you down adam, but here is some little advice:

1- for your 8 port, check your engine compression with a pressure gauge

2- take it apart to see what's going on

3- Never run your engine without checking temp with a temp gauge


Only my 0.02 Euro

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Old 04-17-2003, 09:42 PM
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Default Tired of 8 port problems

I must of got lucky and got a good hyper port.I have never had any tuning problems yet (knock on wood) My savage is a wheelie machine,so I am going to a 16 tooth clutch bell. For your problem,I might try putting all your mixture settings back to factory and start over. Like said before,If your sleeve or piston was bad your engine would run bad at Hi and low rpm's I would think. Good luck
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Old 04-18-2003, 12:07 AM
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Default picco

The .26 still is running good. Have not had a lick of trouble with the pull start. Runs great. Only has two needles on carb. It may be too soon to tell.
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Old 04-18-2003, 01:09 AM
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Default Tired of 8 port problems

I don't have compression gauge, but it does have good compression still. I did take engine apart and put back together. Did everything short of putting high temp RTV type gasket material everywhere. The carb seal probably could use a little work, since even when tight it still moves the tiniest (is that a word?) bit.

I'm guessing air leak.

Temps run around 270, 280 F.

The piston top is pitted in a crescant shape around the edge of the piston from booster ports towards exhaust port. Nothing in the center of the piston or front intake ports.

I'm guess air leak at carb still, but who cares, since I just sold this motor to Buggies_R_Us. Good luck Ram.
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