Great content. All I have left are my Poulan saws I’ve collected from people that throw them away and I get them running again. The only good saw I had was an older Husqvarna 55 that was stolen out of my carport. Bad thing is saws are so expensive these days I’m stuck working with smaller saws running bars a little long. Works for me but the clone saws sure are peaking my interest .
I know when we played with nitromethane in some of the HF motors it’s better to be rich than lean! The nitro/methanol allows you to run much more timing advance and still be within a safe level since it doesn’t detonate as easy as a more volatile fuel like gas.
Definitely wouldn’t be surprised if it needs a fair bit of timing played with. But impressed it’s running like that off the bat. I’m one of those guys who knows just enough to be dangerous so don’t listen to me lol
I read through the comments before typing... and agree. Before reading, I thought still way too much fuel. Im clueless to running nitro in small engines but have a little experience with it through helping a good buddy that drag races with it.
It is not sealing properly. I'm starting over with a new carb. I think I didn't get the needle seat drilled perfectly center. I had it sealing with lots of spring pressure, but I am told this isn't good. Gonna give it another shot, this time being as perfect as I can be with drilling the seat. Then try again with a low pop off pressure. Not that I even know how to measure the pop-off pressure...
You might secure the powerhead then hold it at wide open throttle and tune the high jet by ear to optimize your carb adjustment under a no load condition then tune from there before making any more major changes to the saw
Nitro needs to be ran a lot richer compared to gas proper a/f with 100 percent nitro is 1.7 to 1 compared to 14.7 to 1 for gas and with the slower burning fuel the timing needs to be advanced. Cant say for a chainsaw but vehicles running gas or methanol will typically have timing between 25 to 35 degrees before TDC but nitro engines running 50 to 65 degrees before TDC
@@TroyMcQuillin how much nitro are you running? What I am using is 30% nitro, the rest is methanol. The fuel consumption is crazy! I can't imagine it lasting for more than 5 minutes for an entire tank. Are you just adding a capful or something like that?
Nitromethane needs mixed with alcohol. Your carb will need modified for alcohol. Yes that will consume mas quantities of fuel. Nitro propane will mix with gasoline and give you the same results with a little tuning. What percentage you run depends on how much heat you want to make.
@@TroyMcQuillin okay, that explains a lot. I see what you're doing now. Yeah, this is intended to be a full tilt race saw. Absolutely would be impossible to use as a work saw.
I'm guessing you mean advance the timing, also nitro and alky are very forgiving when it comes to running rich. So I'd say it's just extremely rich. If the saw is pretty, Virgin may be low compression also. Sorta a guess, but I also run alky in my dirt cars so do have some v8 and alky experience.
Check your email and give me a call. A Lot going on to get it up. timming not the issue. Coil is an issue and port job plus plus plus I have over 40+ hours into my build. I will post a video of mine running so you can see where it can go when. You get it right. 😊
Unburnt fuel usually means you need to start the burn earlier, assuming the AFR is correct. I think nitro burns slower so you need quite a bit more advance. And a strong spark
Don’t know anything about nitro but I’d guess if it starts well but doesn’t rev, it needs advanced. But personally I’m guessing it’s something like poor fuel atomization. Then again they pretty much just pour fuel into nitro drag race engines so 🤷🏽♂️ Wrong fuel percentages maybe? 🤷🏽♂️ Cool regardless 👍🏼
I'm pretty sure it is four-stroking. This means the air-fuel mixture is either too lean or too rich. Considering the air-fuel ratio for nitromethane is 1.7:1, I guess the mixture might be too lean. Update: The flammability limits are approximately between 6 : 1 and 0.29: 1 (mass ratio of air to nitromethane ). I guess you are not below 0.29 : 1, but above 6 : 1.
nitro needs more timing advance, it burns slow top fuel runs 50-55 degrees advance, im guessing your running about 20% nitro so idk what you will need but defiantly needs a timing advance
