Wasp .26 tuning question - it skips

[Oxyacetylene]

I have a wasp .26 that I have been running for a few months. I love the engine. During the colder months earlier this year it ran great, good power, smoke trail, and ran about 215-225 degrees. Now the weather is getting a lot hotter and more humid. The truck takes off good but starts "skipping" when trying to accelerate to WOT. I should lean it out to compensate for the increased humidity right? Is this a HSN or LSN adjustment to make it run right again? I also ordered a Nova Race Pro cooling head to help with the increased temps from warmer weather and leaner tuning... I guess it would be more of a HSN adjustment since right now the needle is flush with the top of the sleeve it is in and still has a lot of room to lean it out? Right now it smokes good at low rpm's but not much when it gets to WOT.

 

[pissant]

yea i would lean the HSN out a bit

 

[Markanthony]

Your going to love that Nova head. I put one on my Wasp .26 and temps went from about 240 to 180. But it is really sensitive to weather related temp changes. I would reccomend a new gasket aslo. Tower has them in stock. .2mm gasket.

 

[DOGPILE]

Surely you mean lean it in, turning the needle out will give more fuel so it becomes richer.

 

[Error401]

Leaning it out means running the HSN in. Anytime the term "to lean" is used it means to screw the HSN in. Same goes with the term "richen it up", or "richen", means to screw the HSN out.

The weather will affect tuning alot. If you're running below 230, then the engine really isn't getting up to proper temp anyway. If it's broke in good, lean it till the temps get to arround 250 near the end of the tank. I run mine (Ofna Outlaw 26, but same engine different branding) at 270 and it's a monster.

 

[Oxyacetylene]

I tuned it some this weekend and got it running a little better. With the new head it seems to run about 30 degrees cooler than with the stock head. I have leaned the HSN about a full turn and it seems to do better, but it was really humid this weekend so that might have affected it too. I believe I need to clean my air filter too just to be sure that isn't choking it any. As far as the temps towards the end of the tank mine is pretty consistent, I run the primerless tank and I added the hayes 2oz header tank. I guess I just need to crank it down some more (HSN) and stop being over protective I guess I just didn't expect it to take that drastic of a tuning change for the weather, but then again it is averaging 40 degrees warmer weather and much more humid than when I tuned it during the winter months...

Should I lean the LSN any? If I do I will need to readjust my idle screw so it doesn't idle so high...Right now it idles great and has great throttle response....just from midrange to top end it starts winding out and then kinda acts like it is trying to stall then it accelerates for a few fee, then kinda stalls, then accelerates again. I'm just afraid to lean it too much, but if the temps are OK then I guess it would be fine. I have a good smoke trail on low-end but at WOT there isn't much smoke...

 

[Error401]

Hmm. Run a search here on "pinch test". The pinch test is the best way I've found to tune the LSN. It kind of sounds like you have the LSN tuned, but it's odd that it wouldn't smoke from midt to WOT. I'd try leaning it up slowly and see if it affects the high end running, but keep an eye on the temps and compensate the readings for the new head. I'd try to get it up to around 250 with the new head and see how it runs.

 

[Oxyacetylene]

Ah yes, I forgot about that test. Weather permitting I'll try that soon and see what I get.

 

[Oxyacetylene]

Found the problem. It was the throttle servo. It may be the failsafe. I am running the Ofna one. Maybe it is picking up interference, but it only seems to twitch when the engine is running. I yanked out the failsafe for a test run and it ran perfectly...

 

[El Pirata]

Let me guess the Ofna mini failsafe? They've been having some problems with that one.