Maybe pull the carb off the P5 and try it on the BTT, see if that solves the problem, if it does, then you know its your carb.

I might so that too as the P5 will run all day. Just something stupid and I will figure it out probably....

Sometimes at the track you get stuck one-minded it is the tune. We did try several things to rule out glow plug, clutch, pipe, fuel delivery but anywho..... I am going to look at the carb next.

Like houston said, flush the HSN, but try that P5 carb first.

hudy break in bench
 

trying out a hudy break in bench has anyone got any suggestoins when running in nova engines on this thing??
cheers

so my btt started to idle like crap and was stalling and after blowing two nova 6 plugs, so at the end of the day I took apart and noticed 3 or 4 heavy scratches running down the piston.
could this be the result of the element in the plug dropping out???
either way it needs a new piston and sleeve:(

use a competition heater or aluminum foil around the cooling head to keep the temp up , as the prop will cool the engine quickly. 1/10tire foams work well too

You have to turn the carby around so with the blades on check that it wont strike the carby, Make sure all bolts are secure. I use a old towel and keep it under the exhaust to collect all the fuel and oil.I also make a template out of cardboard and place it in between the carby and head the amount of air that the blades turn out cools the engine to much...all my engines get the first 800ml to a liter on the bench where i can keep watch and heat into the engine... Then in the car..

Yea, sounds like your engine ingested the glow plug element. If the scratches go all the way up the piston past the oil rings, it will cause the problems you are describing. Im suprised the #6 plug did this. this has hppened to me twice with #5 plugs.
If the engine ate the element there is a good chance that it got into the rear bearing and damaged the races as well.

The engine performed just great during the race yesterday. 10ºC ambient temp and the engine was approx. 100ºC (made only one temp measurement). 9901 pipe, 41001 header and 5,5mm venturi. When I drag raced down the straight alongside a Ninja JX21-B02 engine with 6,5 mm venturi, my car had the same acceleration and topspeed ;). I don't know if the 41021 header would have made similar performance. Didn't have time to make an comparison during this one day race.

BTW: just got my 4,7 mm venturi... I guess it will test my tuning skills to get the settings right... :D. Its so different how different engines reacts to venturi sizes: I've no problem tuning Novarosssi engines and my sons old Sirio (Novarossi carb) engine with a 5,5 mm venturi. On my practise engine (STS D21T with Novarossi carb) anything smaller than a 6,5 mm is impossible...

Be sure to check your pipe as someone has already suggested. If the pipe has any restriction , the restriction will be at the smallest point, most likely at the exhaust press port. When your tank has more fuel in at, like at the first of the run, it may not take as much press to push fuel to the engine. 4 minute is you have less fuel, more air, fuel may require more pressure. Exhaust port on the pipe may not be completely closed, but may be clogged enough to reduce your pressure and cause a problem. Just a theory, but I've cleaned a lot of pipes and you would be surprised what comes out!

Yep, I thought of that. Ran it on 3 pipes. An OFNA 086, Nova 9886, and a brand new never ran before OS 2090. Did it on all 3 pipes. Other 3 buggy engines will run all day and night with all the same parts. I am getting ready to tear it down here in 30 minutes actually. I will take pictures tonight or tomorrow morning.

Did you try the P5 carb?

I have not had time tonight. I am tearing the carb on hte plus-4btt apart right now and trying to see of I see anything. Will post pics in a little bit....

ok, so I took everything apart and have some pictures. Everything looks really clean. The carb looked good and the orings look brand new. Flushed the whole carb out with denatured alcohol and some air. No dirt came out and looks as good as new. The piston and sleeve looked pretty good, no signs of cracks, sleeve is really smooth, etc.... I have a picture of the farthest i could push the piston up the sleeve and is really tight at the top still.

The only thing I saw that might cause a problem is one of the shims on the head button was a little rough looking. I had some shims so I put new ones on it and at .80 for now as I do not have the shim to go .70 right now. Maybe not sealing good and the top of the sleeve is a little nicked but it ran fine for 3 race weekends like that. I am going to put it back together and go to the track Wed. night and bring the carb on the P5 and see if it does it or not and switch to p5 carb if it does.Pictures are not the greatest but hopefully it helps.


http://i45.tinypic.com/ors5z4.jpg

http://i45.tinypic.com/28uod41.jpg

http://i45.tinypic.com/bjiudx.jpg

http://i46.tinypic.com/11jcaxw.jpg

http://i45.tinypic.com/1zwyxc0.jpg

http://i50.tinypic.com/35l5hz5.jpg

You may need to resurface the top of the sleeve. Looks like there are a couple deep scratches there.

Yeah that is what I was thinking after looking at it but all is well for the most part.

Well, I believe I have found the problem...... What is the chance of getting a bad 17011 bearing from the factory. I looked at things a lot closer after I put the engine back together and i noticed some play in the bearing. I am not talking the crank moving front to rear a little as that is normal. I can take the crank and move it up and down to speak in the bearing. I can turn the crank and the inner race does not move. Like the crank has wore down or the race is too big in the bearing. As soon as I put it in I did the motor clean test and it passed. I noticed oil on the bottom of the engine while tearing it apart but I also had a fuel guy spill fuel while "playing" with this engine at the track. The crank looks fine and perfectly smooth feeling and looks fine but does not begin to fit correctly in the inner race of the bearing.

I went and looked at the CRE P5 I have and the new bearing in it is super tight and I have none of that play and it runs fine and never flames.

What are the chances of getting a new bearing that is out of tolerance bc I think I might have.

I honestly have no more than 10 minutes on this bearing since I had to pull the engine and put something in that would run for the mains.

Coincidence or not?


What should the measuremant of the crank be at where it meets the front bearing? I would like to measure just to check if it is the crank?

Bingo! 17011's got really crappy. They were really good, then got really bad. Our local hobbyshop has a huge track that draws many racers and can't give those bearings away.

I had heard grumblings about this, but at the same time I have heard these are still the best bearings on the market. It sucks to be out $30 but sometimes the hassle is not worth it trying to get them to do something about it. I think I will roll with a $14 TKO. Put one in my Speed and has been very good!!!!

Well this sucks.....

At least you found the problem, I have TKO ceramics front and rear, they are excellent bearings, long life and high quality.

how can you give people advice or suggestions? ive only seen you at two races and you were pretty clueless.

you are a perfect example that you cant believe everything you read on the internet..

Clueless about what?

Yeah I only raced 3 races but I run my engine and car a lot and I've worked on it a lot so I KNOW WHAT I'M DOING WITH ENGINES. Are you saying TKO bearings aren't what I'm saying they are?

I only give people advice or suggestions about THINGS THAT I KNOW ABOUT. IF I DON'T KNOW ABOUT SOMETHING I WON'T SAY ANYTHING ABOUT IT BUT I KNOW ENOUGH TO SAY TKO ARE GOOD, HIGH QUALITY, LONG LASTING BEARINGS.

You're kidding me right?! You must be.

easy there cowboy.. if you work on your engine ALOT that says ALOT.

i run gallons of fuel thru my engines and unless the sleeve has to come out it doesnt come apart.. not even a little... so if your telling me you pull it apart a lot there is a problem.. last time you were at the barn you were running an engine on the lean side of destruction.. dont tell me you know what your doing.

you're kidding me rt? u must be.

nova has a new bearing supplier , the 17011 bearings are just fine now

there were a few bad ones in mid-late '11 that were a little out of the allowed clearances that they should be held to


whats the batch # mjealey

i will put a bug in someones ear about the bearing if you can take a pic of the header card with the batch#/yr code

I take my engine apart to clean it and check and change bearings or what ever needs to be done to it, does it mean I don't know what to do with an engine, thats why I have to keep taking them apart? No.

Now back to the point. You're telling me I don't know enough to say what bearings are good and what bearings aren't. Well thats not true. Yes, I do know what I'm doing.

Yeah the engine I was running at the barn was running lean, but it doesn't mean the whole engine is perfect. I was tuning the engine on the box and it wouldn't run any richer than where it was at. I didn't race that engine. It was on the track for a minute than I took it out and put my P5 in it and it ran fine and I raced with it.

There was a problem with that engine.

So tell me your horrible experience with TKO bearings to prove legitimacy in your criticism towards my advice/experience.

easy there choppa , he didnt say a thing about TKO bearings

I know, but he was criticizing me because I gave advice about TKO bearings. If TKO bearings are good, I should be able to recommend them without people thinking I don't know what I'm talking about.

i am absolutely positive his criticism wasnt from your suggestion of peters bearings which are a great cost effective alternative

I know, it was of me giving advice about TKO bearings, as if I was saying something un true, we all know what I said about TKO bearings are true.

VIVA LA NOVAROSSI!!!:D

Haha.

just so we r clear i just quoted the last thing he said because i didnt wanna multi quote 20 other posts..its not the bearings its everything else..

No problem Houston, I can pull it for you and take pics and give you anything you need. I will be busy with work for a few days but I will pull it and get the info. Assuming it is not the crank.......

as if the other things I said was not good advice or help, right.

lets see:

trying a carb from a working engine: to see if the carb is the problem, and if it still doesn't run with the other carb, it must be a problem with the engine

fuel delivery system: he said it would start flaming after a few mins of running, this makes me think its a fuel delivery problem, I'm sure others thought the same.

I can continue but I don't feel like it, and I don't need to.

If I have advice or a suggestion for someone, I will share it and if anyone disagrees with my advice/suggestion, they say it. end of story...

yes please double , triple , quadruple check everything else beforehand but if it does end up being the bearing let me know

man. code on the brng also

should be something like M11-M13 ish if it was one of the bearings that were having issues .

novarossi remedies any issues they have with manufacturing but they need to know about the issues or its very hard to do so

i am in direct contact with novarossi factory but you would have to preach your case to the place where you purchased the bearing which i would need to know also

email me any pics or correspondences to [email protected]

Personally I replaces the bearings if there is any play back and forth on my race engine. A little more large on the practise engine. Do all of you allows a little play back and forth?

Monty, does this go for the rear bearing as well?

I replaced the rear bearing in my Bonito and the ceramic Nova bearing had a catch in it, so I took it apart to inspect and found an odd mark on the inner race.

It looks like the defect came from the factory, kind of like a bad cast.

I will see if I can take a pic that shows what I am talking about, otherwise I may just mail it to you and let you check it out.


On another note, I received my engine yesterday. Will hopefully get a chance to run it Thursday. Appreciate the service!

[IMG]http://i1061.photobucket.com/albums/...010_084114.jpg[/IMG]

+1 Wheelie

You always have to take into account the source of the information. Info from a novice does not carry as much weight and validity as that from someone with more experience.

Experience is no guarantee of good advice..

Its possible that the material used to machine the races had a void of sorts

I would say that is a manufacturers Defect but its not so easy to convince those in charge of replacing the parts due to defects . Whats the code on the outer race ?