XRAY - Model racing cars

1 gallon break-in 8 idle tanks and 5 on track rich tanks.

engine ran great for half a gallon. completely lost its pinch after 1.5 gallons. i have two buddies that also are running them and have had issues with airleaks/idle. was properly broke in and not ran hot. dunno what happened to it. my jp modifed's i have nearly 7 gallons on.

kyle

Kyle that is the EXACT same thing that happened to the guys I know.

I had a litlle issue with the idle but that eventually got solved. The only problem I have is that one screw from the backplate actually broke off and now the rest of the screw is set flush in the crankcase. Talked to Dave @ Fusion and he said to just send it back to get it in another crankcase. So no Plus 21-5 for me for now

I think the Plus 21-5 is designed like the VSPEC. Instead of mechanical "pinch" the VSPEC engines develop true compression through the fuel and oil surrounding the piston/sleeve.

Novarossi must be trying to design a true compression engine like O.S. has come up with. The result is much higher runtimes and RPMs. If so, don't worry about how easy it is to turn the engine over, that is the way it is designed and not a sign that the engine has lost its life or usefulness.

Now airleaks are an entirely different story.

nitro racer.....

i believe that when you are racing and your engine continues to die when it reaches 200 it has lost its pinch. the engine still has plenty of power the pinch holds the idle.

also the other 2 engines you can barely turn over they have so much compression.

kyle

What I mean is that there is a difference between pinch and compression. If it won't idle (and there aren't any air leaks or anything else wrong) the engine is probably worn out and has lost its compression. However, an engine should lose its pinch early on and that is a good thing. Losing compression is not.

wrapped with foil and a sock the engine idles at 215 with rich rich needle settings. i dunno what happened to it really. i have had several nova's i usually get at least 6-7 gallons.

kyle

lol in that case my p5 just got broken in at 4 gallons... at 3.5 gal it would get stuck and would have to pry it with a screw driver...


we raced at our new track here, 220 foot straights. with a 13 tooth 1/4 way and you are topped out.

i have a 03-04 p5 with a jp2 and a 15 tooth bell
bud had a 21+5 14 tooth and a jp-1

we were dead even the whole way.
his engine was full song and mine wasnt... i didnt have a good 14 tooth to try, but 15 tooth made it top out 1/2 way instead of 1/4th,

Just cruzin' the Forum, Maybe starting from the begining would help!! I read, on another topic N18 & Nt18t forum, There is this guy geezatec, under two topics, Engine not working, NT18T Tuning. He makes sense on adjustment.
Only a opinion!! Later! Just cruzin the forum!!!

Hello,
I have a Novarossi Plus 21-5: good engine, but I didn't find the way to make it work properly.
This is my problem:
- to start I need to set up the mechanical minimum in mid-high position (if not, it puts out)
- after 5 minutes (temp 95° C) the minimum decrease (risk to put out on narrow curves or in case of car stop) and I need to increase it more. But this generates higher temp (up to 140°C!!) and risk for the cluch !

I use 25% fuel (Novarossi), 8mm insert in the carburator and 7C plug.
What m'I supposed to do ?
Plase, any help ?

more...

Last Sunday I made a race (Italy, near Milan):
cloudy day, but hot enough (25-30° C).

I prepared my Plus 21 and I started to make the qualifications (5 minutes each).
The first went good.
But the second was a disaster ! I didn't change anything on my engine (I though, "it's ok, don't touch anything"), but I wasn't able to start my engine. It's started for one or two seconds and then out. (I tried three different glow plugs, but nothing!).
Possible that from the first to the second qualifiyng session something has changed ?? ...but what ?
In the afternoon, during the semifinal race (20 minutes), my Plus 21 went off three times, compromising my race. ....and it's third one !

I have to know what setup you have on the carb. First things first.

One, determine the compression. Does it take more than two fingers to turn over?

Two, Mechanical adjustment For idle speed(air gap) in millameters.

Three, How many turn your main screw to seat closed. Count how many so you can return to it.

I only can go by the temps you had given. Those didnt look good. That hi temp it wont take to long. Who knows maybe your glow plug driver wasn't hot enough!! Give me info we'll figure it out. Be patient, we're a world apart. And too the other people having the same problem.

I race Novarossi engines and the 21-5 plus. I'm very satisfied with the performance and stability but I've also noticed that using two Xray fuel filters makes the engine go rich and very difficult to adjust.

Other than that I can not see any problems. The fuel is very important and so is the clutch, pipe/manifold, plug and adjustment.

I've raced 3 engines without any problems.

Regards
Peter Harder
Novarossi team driver

You may have an airleak. Check the carb boot, and the o-rings that seal the carb in the block. Put some sealent when you install the carb, check your tank for cracks, and put on some fresh fuel tubing and try again.

I would find the original settings for the carb and start fresh. I'm sure someone here can tell you that info.

All the tuning in the world won't fix a motor with an airleak.

Or maybe you have an engine bearing going?! That's been a problem with a batch of Nova motors.

Good Luck!!