rotorhead787

I just bought a nitro hammer and am having some issues with the mixture screws. I set the hs screw to 2.5 out but the boat would not idle at all. I had to turn the Idle mixture screw out to 2 turns for it to idle but it would not rev past idle it would just die. After lots of tuning I have the Hs screw out 7.5 turns and the Idle mix out 1.75. The boat runs too good for this setting (like it's already broken in and tuned) so I turned the Hs screw out even more and the boat still ran good....? So I stopped running it 'cause it's scaring me. I haven't been able to run a whole tank thru it without it stalling after returning to idle from half throttle. Any ideas on what might be wrong?

rotorhead787

I'm thinking I either have a vacuum leak in the case or something is wrong with my carb.

Jerry Dunlap

Definitely sounds like a fuel draw issue. Check you tank and fuel lines. With fuel in the tank, blow into the vent line to see if fuel easily exits the supply line to the carb. Disconnect the line to the carb for this test. You might try completely removing both LSN and HSN and blowing out the carb.

JD

cmiller73

Wehn I got my son's in it had a cracked fuel tank right where the screw holds to the cross stringer. The fuel was leaking everywhere. I basically couldn't get it running. I changed tanks and now I can get it running , but not with the settings that the book says. I has th HS needle at 3.5 out and the LS needle at 4. It seems as if at 2-2.5 on the HS needle the fuel doesn't flow into the carb.

rotorhead787

Just wondering, but I have been operating the boat in 40 deg. F weather would that affect it?

saleens7

check the pressure nipple on the exhaust....it could be loose....i had the same problem with my SW, it wouldnt do past 1/3 throttle without stalling or bogging down, i tried a bunch of different needle settings and it did not work....(does the pressure nipple unscrew or is it welded on to the exhaust?? if it screws on, locktight that thing in there and be done with it...you should check your tank for any leaks and do the same with the lines...also zittie all the lines on the nipples so they doen come off or get loose//

rotorhead787

I took everything apart looking for leaks but didn't really find anything so I took the carb apart and blew everything out. I found the LSN spec on tower hobbies and they say (head is 0.8mm IN from flush w/throttle arm nut) so I put a hair less then 1mm and the HSN back to 2.5 Out and the boat runs and idles. I haven't ran it on the pond yet but we'll see!

cwaterhunter

sounds more like a fuel delivery problem.. iam new to boating but been into RC for a while.. nitro motors are all basicaly the same.. i have a t-maxx also with a 3.3,, had the same problem.. checked found a crack in the fuel tank.. replaced.. runs awsome now..

rotorhead787

I checked the tank and lines and they are all good. I can block off the supply line and blow into the pressure line with no leaks and fuel flows easy out of the supply line. I'll have to run it this weekend and see how it goes.