Hello,

I got my Duratrax Raze in today. Its my first nitro RC ever. I can't seem to get it to start. I have gone through the troubleshooting but I can't seem to figure it out. The pull start it really hard to pull when the glow plug is in, but it can be pulled. However with the glow plug out, its really easy.

Maybe its suppose to be slightly hard to pull. I just some guidance here.

Any help would be highly appreciated.

Thanks
Disjaukifa

Being hard to pull is normal, this means there is pinch and compression, when you go to start it just use short but quick pulls, also you could try taking off the air cleaner and putting about 7-8 drops of fuel in the carb, put the filter back on and try to restart, heating up the engine with a hairdryer or heat gun will help to start it as well. Also make sure there is fuel in the fuel line all the way up to the carb. Good luck to you. Let us know your progress!!!

Try loosening the glow plug slightly. You may have to mess with it a little bit. But once you get it started, then tighten it back up. New engines have alot of compression so it can make it hard to pull the pullstart. It'll get it easier as you break it in.

Use a heat gun or hair dryer to preheat engine before starting. Once you get it started make any SMALL adjustments you need to make to keep it running for engine break in. Don't start turning needles like crazy. Small adjustments. Until you get used to it , it could help to make a prestart checklist. First thing you should always do is make sure your transmitter/radio is on,check fuel, check glow plug check glow starter,etc... Once you get it running follow engine break in instructions.



Heat cycling for stress relief
Stress relief is accomplished by repeatedly heating and cooling the engine-short engine runs followed by complete cooling repeated many times. ABC engine break-in involves such heat cycles, betit is not the same proceedure as is used for non ABC engines.

ABC break-in the inside story
Abc engines require a shorter break-in (heat cycling) than engines of the past- less than 45 min. for most. To attain and maintain maximum power levels, however, requires adherence to an entirely new set of break-in rules.
The primary objective of ABC break-in is to maintain the delicate top of the piston pinch zone while allowing the internal engine components to heat cycle with some minor smoothing and allignment (crankpin, wristpin, rod journals, etc.).

Here is how this is achieved:
FUEL- Use the same fuel for break-in as you will for normal operation. If you break-in your engine with low nitromethane fuel, e.g., 5% and then jump to 20% for actual running, the piston / cylinder fit will be too loose. Five % nitro doesn't generate as high a combustion temp., so the cylinder won't expand as much, and the pinch zone will wear more than if the cylinder had pulled away farther, as it would with the hotter burning, higher nitro fuel.

2- vs. 4-cycling operation
If you run a 2-stroke engine then you have heard of 4-cycling. When a two stroke engine is operated very fuel-rich or at somewhere below 1/2 throttle, it begins to fire on alternate crankshaft revolution. As the mixture is richened at wide open throttle, the ehaust sounds like this as it breaks from 2-cycling to 4-cycling: " RRREEEAAAHHHHHHH."
As the throttle is reduced to about 1/2, the exaust sounds like this, as it breaks from 2-cycling to 4-cycling: "RRRRREEEEETAT-TAT-TAT-TAT."
With both examples comes a simotanios loss of rpm with the change in exuast sound. This is 4-cycling. Learn to avoidit. Because the ABC-type engines were originally designed as WOT racing engines, their pistons and cylinders operated happily. Today, ABC engines are also expected to idle and throttle reliably. Unfortunatly this allows them to cool excessively, especially below 1/2 throttle, where poor cylinder scavenging (clearing) causes them to 4-cycle and wear away the critical pinch zone as the piston sleeve cools and tightens around the piston
Throttling is a necessary phase of running nitro engines in cars, so you can't simply eliminate it from your routine, but do not allow the engine to 4-cycle during break-in. Afterward, when engine components have been stess-relieved and bedded in through heat-cycling, the wearing effect of 4-cycling will be minimized.

Tight ABC piston/cylinder assemblies
Some new Abc-type engines are so tight at TDC that for the first few times the engine is cranked over and run, the possibility exist of damaging the connecting rod, crankpin, and piston. To avoid this, preheat the cylinder and the head with a heat gun or a hair dryer. This preheating expands the piston sleeve, and that minimizes the potential for stress on all the engine components during initial startup.

Hey Guys,

I still couldn't get it to start so I decided to go over the manual completely. I saw that all the factor screws are set, I had adjusted the high speed on but I decided to check the low speed needle. Its suppose to be at 12 1/2 turns out and mine was at 10. I set it correctly and after 2 pulls the engine fired right up.

I had thought about checking it yesterday but decided not to. Thank you for all the help and information!!!

-Disjaukifa

glad to hear you got it running! [8D]
When I got my Raze I also had a hard time starting it the first few times due to the pinch being so tight. After the break in was done it starts really nice now, one or two quick pulls and it fires right up.

Also check out this thread with lots of info on the Raze
http://www.rcuniverse.com/forum/m_5149307/tm.htm