New built motor hard to start.

Wally Dog

Member
I just finished building a new motor. I'm trying methanol for the first time and purchased a meth carb from NR Racing. It takes quite a few pulls to get it started. The carb doesn't have a choke and I'm using an ultra light ARC flywheel. Is this normal for alcohol engines? Also, my timing might not be set correctly, would that have an affect on starting?. The flywheel comes at 32 degrees and I currently have a 2 degree offset key. Any advice would be appreciated. Thanks!
 
A light flywheel is not going to carry through the revolution's like a heavy flywheel .
What other mods cam and compression changes ?
Once started how does it run ?
Is it a modified clone/predator style float carb ?
Timing can affect it but would need too be out of whack 2 degrees should not do it .
 
A light flywheel is not going to carry through the revolution's like a heavy flywheel .
What other mods cam and compression changes ?
Once started how does it run ?
Is it a modified clone/predator style float carb ?
Timing can affect it but would need too be out of whack 2 degrees should not do it .
It is a modified predator style carb (stock appearing). F-275 cam. 28/32 valves, milled, high compression head. 1:3 gage rockers, 36lbs springs. Stock stroke/crankshaft. Dished piston has been replaced with flat-top. Once started it seems to idle fine. I haven't rev'd it up much yet as I'm not sure how much break in period it needs. I let it idle around 2000 RPMs for 20 minutes.
 
You may need to carry a nut driver with ya and pull the air filter and kinda block the carb a bit with your hand till it takes off.
 
You may need to carry a nut driver with ya and pull the air filter and kinda block the carb a bit with your hand till it takes off.
Thanks. I bet I can come up with something to put over the air filter to choke it and be able to quickly pull it off.
 
If its as cold where you are as it is here you may think about trying to put a torpedo heater on it for 5/10minutes prior to trying to start it. Otherwise the rag/bag on the filter is a good idea for a choke.
 
On cold or cool nights we have to manually choke ours to get them to fire decently. Yank air cleaner, hold hand over carb and fire it.
 
the way we started the limited modifieds is to take the air filter off place your hand over the carburetor (manual Choke). Pull the cord. if it's still hard to start idle jet may be too lean. you can also use starter fluid but be careful with that stuff that's the either mentioned above. or a squirt bottle filled with methanol just squeeze some into the carburetor.
 
I saw a guy at the track one night that had a little bottle of methanol, he'd plumbed a little valve into his fuel line and would prime it that way.
 
Just built a similar engine and had the same problem. I assume you're also dealing with cold ambient temps. Problem is methanol flash point is around 54 degrees F. Best luck I've had so far is fill the float bowl with gas, give it a quick shot of starting fluid straight down the open carb bore, hold the throttle half open till it fires. If it doesn't pop at all it probably needs another shot of starting fluid. In my cold shop it won't even restart after running for over ten minutes with out another shot down the carb. I always used starting fluid on cold starts of alcohol V8 race motors while most guys I raced with never left home without a squirt bottle of gasoline.
 
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