jmb52760

Just bought a used Rossi 60 with an aftermarket muffler. It has good compression and will start on the prime, run hard, and then die. I have adjusted the high speed needle from lean to rich with no success. I am hesitant to move the low speed needle. Can anyone tell me what settings (turns-out on the high and idle needle valves) to start with? Is there possibly something else that I am overlooking? (Have been running OS, K&B, and other engines for 30 years, I did have this problem once on a Magnum 40 - put it away and never ran it again) Thanks in advance!

redfox435cat

ran across this today. turned out I crossed my fuel line. oh was I not supposed to admit that[:'(]

it starts so it's not the plug.
what fuel are you running. Rossi's like 5%. there a euro actually Italian engines and with most euro engines they are designed to run low nitro since the cost is so astronomical over there.

try using 5% nitro and use hot glow plugs because lower nitro fuel burns hotter. nitro has a low flash point so it ignites at a cooler temp so the more nitro there is the lower the flash point of the fuel.
if it's revving then dying it's starving of fuel. pull the carb and clean it, make sure the venturi is clean, replace the fuel lines or at least make sure they are supple and have no air leaks at all
set the low end so the screw is even with the barrel to start, the high end should run at 2.5 turns open and lean it from there.
All my Rossi have been a little stubborn during break in. more engine are, once there broke in there is no stopping em, also they run best with the stock mini tuned silencer

on the other hand it's a used engine. personally I never buy used equipment unless I know they dude. just me, At this point I would do a tear down and look at the piston/liner. and the bearing while your at it.

jmb52760

Thanks Red!

Definitely not the fuel line, we are running on a test stand and can see everything. Fuel lines are new and fuel is flowing well when the needle is rich and not so well when leaned out.

I think you may be right about the fuel. It says that in the manual. Trouble is, I only had 15%. Roadtrip!

The manual says nothing about needle settings.

I'll try these suggestions and let you know in this thread if it's still around. Don't know how soon I can get to it again.

Otherwise the engine seems really clean. Very good compression and smooth bearings as far as I can tell.

This is my first engine from an unknown source. A friend's grandfather got out of the hobby and gave him all of his stuff. Got a perfect condition Calypso kit (not built) in the deal as well, couldn't pass this up.

TimC

jmb52760, I have a .60 Blackhead in storage. I was running it with a pitts muffler. I can check the turns out on the needles if you like. This might put you in the ball park.

jmb52760

TimC,

Thanks for the offer. Please do, I think that would help. I still haven't tried Red's suggestions yet, I'll probably run it again this weekend.

I believe this engine is a blackhead as well, the finish on the head and on the drive cone is black anodize.

TimC

Here's a photo of mine jmb. The high speed needle was out 1 and 3/4 turns from lightly touching. The low speed needle was out 5/8 turns from closed with the barrel in the full throttle position.

jmb52760

Tim,

Just checked the adjustments. Appears the low speed was in the same position as you describe. I've definitely tried it with the high speed at 1 3/4. I'll try Red's fuel suggestion this weekend.

Thanks again for checking.

TimC

jmb, I'm betting redfox hit the nail on the head. I've only run 5% nitro with a castor blend in my Rossi. I researched here at RCU before running it the first time. I think one of the benefits of growing old is that I've quit trying to re-invent every hobby I get into.

jmb52760

Tim C,

I think you are right. I joined RCU just to get help with this and now I'm hooked. I hope I can pay it forward.

Problem is, everytime I see a question that I know the answer to, someone else has beaten me to it.

TimC

If they beat you to it jmb, then contradict them and start a flame war.

jmb52760

Here is the update:

I tried it with FAI fuel. It still had the same problem, started on the prime, ran hard and died.

For some reason I got a revelation and realized that it was leaning out at idle. I turned the idle mixture screw 1/2 turn out and BAM, it ran great.

Just to check, I tried it with 15% nitro. Same result.

Go figure.

Problem solved, I am going to mount it on my vintage Calypso pattern kit which is nearly completed. It runs great.