Help me out here guys, I'm having a brain fart. Put the stock 25 motor back in the savage after a couple year detour from the hobby and am missing something in my tuning equation. Last time I ran this motor, it worked great but it was at about 1000' elevation. Now I'm about 3500' elevation and things were a little goofy so I set everything at factory settings to start from scratch on the tuning. It runs great on the top end (good temp, good smoke), and the low speed is right where I like it (just before it bogs down during acceleration), but when I release the throttle quickly and the carb slide snaps shut, it immediately dies. If I raise the idle enough, it seems to help, but at that point the clutch is trying to engage. Do I need to richen the low speed some more? With thinner air at higher elevation, will it run leaner or richer to keep the fuel/air mixture proportionate?
Altitude vs. tuning question
- Thread starter supersavage
- Start date
-
- Tags
- tuning
Welcome to RCTalk
Come join other RC enthusiasts! You'll be able to discuss, share and private message with other members of our community.
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
links, including eBay, Amazon, and others.
MotoGod
Hardcore RCTalk User
At Altitude you will have to lean your needles a bit. Thinner air means you need more of it to get the oxygen that the engine needs to keep the mixture correct, which means you get less Oxygen than you are used to and you will need to supply less fuel to compensate for it to keep everything kosher.
So with that said, you should still be able to tune it OK, but it will probably run a tad hot compared to lower altitudes. I remember Ryan Lutz said he had to remove the carb restrictor entirely and lean the engine WAY out to get it to run correctly in Colorado. He ran his engine at 330 degrees all weekend to compensate ;-)
So if you can give it some more air....you might be better off so you can richen it up a bit. You can also try to richen your LSN by an hour or so....and lean the high speed and see how it works. I have a feeling it's going to be a lot of trial an error for you though....
So with that said, you should still be able to tune it OK, but it will probably run a tad hot compared to lower altitudes. I remember Ryan Lutz said he had to remove the carb restrictor entirely and lean the engine WAY out to get it to run correctly in Colorado. He ran his engine at 330 degrees all weekend to compensate ;-)
So if you can give it some more air....you might be better off so you can richen it up a bit. You can also try to richen your LSN by an hour or so....and lean the high speed and see how it works. I have a feeling it's going to be a lot of trial an error for you though....
- Thread starter
- #3
Funny you mention the difference in engine temps. If I remember right, both my rigs were running 230-240. Before screwing with anything the savage was running about 275 but after running a full tank thru my mt2, i never got it over 200. go figure...
Similar threads
