Originally Posted by mjealey (Post 11271747)

Hey guys, I have a Plus-4btt that has been absolutely bullet proof and been running fine for about 4 straight weekends until yesterday. I am running A Werks #6 plug in it with the stock Mugen clutch with the same OFNA 086 pipe I have been running this combo for 2 months. I have about 4 gallons on it. I was 4 minutes into the second 5 minute qualifier. I really have not touched the needles besides an hour here and there on the HSN each weekend and no flameouts over the last 2 months. The track had a long stretch and we twist the motors pretty good but all of a sudden the thing will die as soon as I let off the gas at the end of the straight 4 minutes into the heat. Motor was running perfect, nice and crisp, and only about 255 when i temped it.

I richened the top up a little bit, set it down to get 1 last lap in, made the whole 40 sec. lap and once again at the end of the stretch same thing when I let off the gas it just dies.

Repleced the plug and richened the LSN and increased idle gap, did the same thing in the 3 heat except earlier and in the 1st lap. Only dies at the end of the straight from being wide open for a good 3 to 4 seconds and then letting off to make sweeper curve? Idles fine, sounds great but keeps dying? I did not check it at the track, but maybe guessing front bearing? Need to tear into it tonight or tomorrow any ideas? We tuned on it the whole 3rd qualifier and the same thing no matter what we did. Also tried a #5 (hot) plufg and still did it?

Any ideas besides bearing or what would cause it to die after wide open throttle would help?

Originally Posted by mjealey (Post 11271747)

Hey guys, I have a Plus-4btt that has been absolutely bullet proof and been running fine for about 4 straight weekends until yesterday. I am running A Werks #6 plug in it with the stock Mugen clutch with the same OFNA 086 pipe I have been running this combo for 2 months. I have about 4 gallons on it. I was 4 minutes into the second 5 minute qualifier. I really have not touched the needles besides an hour here and there on the HSN each weekend and no flameouts over the last 2 months. The track had a long stretch and we twist the motors pretty good but all of a sudden the thing will die as soon as I let off the gas at the end of the straight 4 minutes into the heat. Motor was running perfect, nice and crisp, and only about 255 when i temped it.

I richened the top up a little bit, set it down to get 1 last lap in, made the whole 40 sec. lap and once again at the end of the stretch same thing when I let off the gas it just dies.

Repleced the plug and richened the LSN and increased idle gap, did the same thing in the 3 heat except earlier and in the 1st lap. Only dies at the end of the straight from being wide open for a good 3 to 4 seconds and then letting off to make sweeper curve? Idles fine, sounds great but keeps dying? I did not check it at the track, but maybe guessing front bearing? Need to tear into it tonight or tomorrow any ideas? We tuned on it the whole 3rd qualifier and the same thing no matter what we did. Also tried a #5 (hot) plufg and still did it?

Any ideas besides bearing or what would cause it to die after wide open throttle would help?

Originally Posted by mjealey (Post 11271747)

Hey guys, I have a Plus-4btt that has been absolutely bullet proof and been running fine for about 4 straight weekends until yesterday. I am running A Werks #6 plug in it with the stock Mugen clutch with the same OFNA 086 pipe I have been running this combo for 2 months. I have about 4 gallons on it. I was 4 minutes into the second 5 minute qualifier. I really have not touched the needles besides an hour here and there on the HSN each weekend and no flameouts over the last 2 months. The track had a long stretch and we twist the motors pretty good but all of a sudden the thing will die as soon as I let off the gas at the end of the straight 4 minutes into the heat. Motor was running perfect, nice and crisp, and only about 255 when i temped it.

I richened the top up a little bit, set it down to get 1 last lap in, made the whole 40 sec. lap and once again at the end of the stretch same thing when I let off the gas it just dies.

Repleced the plug and richened the LSN and increased idle gap, did the same thing in the 3 heat except earlier and in the 1st lap. Only dies at the end of the straight from being wide open for a good 3 to 4 seconds and then letting off to make sweeper curve? Idles fine, sounds great but keeps dying? I did not check it at the track, but maybe guessing front bearing? Need to tear into it tonight or tomorrow any ideas? We tuned on it the whole 3rd qualifier and the same thing no matter what we did. Also tried a #5 (hot) plufg and still did it?

Any ideas besides bearing or what would cause it to die after wide open throttle would help?

Originally Posted by Dillon71 (Post 11271848)

about a month ago, a friend of mine had the same issue with his nova. It seemed to run good and idle good but flamed at the end of the straight. He just changed the front bearing so he knew that was fine. Changed the glow plug from a nova 6 to o.s p4. Fixed it, ran awesome. Some say that it will harm the head button but he hasnt had problems and the engine is just more reliable. Last week we raced at gas champs where he helped out some others with nova 4btt's that had flame out problems all weekend. Changed to p4's and they ran good and didnt flame. something to try.

Originally Posted by beidle99 (Post 11271900)

Try to richen your LSN some more. My btt was doing the same thing. Ran fine on my regular medium sized track but when I went to a larger track with a much longer straight it would flame out when I got off the trigger at the end of the straight to turn.

Originally Posted by mjealey (Post 11271747)

Hey guys, I have a Plus-4btt that has been absolutely bullet proof and been running fine for about 4 straight weekends until yesterday. I am running A Werks #6 plug in it with the stock Mugen clutch with the same OFNA 086 pipe I have been running this combo for 2 months. I have about 4 gallons on it. I was 4 minutes into the second 5 minute qualifier. I really have not touched the needles besides an hour here and there on the HSN each weekend and no flameouts over the last 2 months. The track had a long stretch and we twist the motors pretty good but all of a sudden the thing will die as soon as I let off the gas at the end of the straight 4 minutes into the heat. Motor was running perfect, nice and crisp, and only about 255 when i temped it.

I richened the top up a little bit, set it down to get 1 last lap in, made the whole 40 sec. lap and once again at the end of the stretch same thing when I let off the gas it just dies.

Repleced the plug and richened the LSN and increased idle gap, did the same thing in the 3 heat except earlier and in the 1st lap. Only dies at the end of the straight from being wide open for a good 3 to 4 seconds and then letting off to make sweeper curve? Idles fine, sounds great but keeps dying? I did not check it at the track, but maybe guessing front bearing? Need to tear into it tonight or tomorrow any ideas? We tuned on it the whole 3rd qualifier and the same thing no matter what we did. Also tried a #5 (hot) plufg and still did it?

Any ideas besides bearing or what would cause it to die after wide open throttle would help?

Originally Posted by mjealey (Post 11272199)

Ok, the front bearing test failed for one. So I pulled it apart and it looked clean inside and the piston and sleeve look really good. Motor was still pretty difficult to turn over by hand. Clean as a whistle inside but I will pull the bearing tomorrow to see if any fine dirt has made its way in. I think the bearing leak had just started and relatively small.

Secondly, I get the bone head of the year award. I pulled off the air filter assembly and there was no venturi in it! I pulled it all off and cleaned everything and I guess forgot to put the 6.5 venturi back in it. That is the dumbest thing I have ever done. My problem was 2-fold. Front bearing starting to leak and a dumb #$% human error. It was tuned for 6.5 and didn't have it in there so no wonder it was lean. It was not lean bogging though and running great until it flamed once you let off the gas. Anyway, I need to get a bearing and replace it before this weekend. I think I should be good. I feel confident after looking at it everything is okay just a really dumb user error I will never make again!!!

New rule also. All my engines get new bearings no question asked every 2 gallons from here on out, maybe overkill but that is what I am doing.....

Originally Posted by chopper82p (Post 11272264)

Make sure your rear bearing is nice and tight with no excessive play as well.

You can go 3 gallons on bearings, if not 4 or 5.

Originally Posted by mjealey (Post 11272294)

I did, real nice and smooth with no play but I am thinking about replacing it too....

Originally Posted by chopper82p (Post 11272264)

Make sure your rear bearing is nice and tight with no excessive play as well.

You can go 3 gallons on bearings, if not 4 or 5.

Originally Posted by Maximo (Post 11272923)

the bearing life is directly related to the conditions the engine is run in..if you run in dusty conditions, especially fine dust, the bearings will need to be changed much more often then someone who runs in a clean environment......17011 is an awesome bearing, but it will not fully protect you in some conditions, dirt will still pass thru it......... So if you run in dirty conditions change your bearings often....

Also engine RPM will play a huge role in how long the rear bearing lasts...If your run a moderate engine on a medium track your likely never going to have any issues... However if you run a high RPM engine on a larger track then your going to see more rapid wear on the rear bearing..especially if they are steel bearings......Bearing life and engine RPM are closely related......A stock steel bearing will last much longer on a 33 000 RPM engine them it will on a 43 000 RPM engine,...... guys who say their bearings last 10 gallons simply do not push their engines as hard as the guys burning down bearings every couple of gallons......... How hard you push the engine and how dirty the conditions you run in are what determines how long the bearings will last............... baby the engines and keep the RPM's down and always run in clean environment and bearings can last the lifetime of the engine..............However take a engine buzz it in the 40K range on a dirty dusty track and you can kill the bearings in 1 gallon with ease.......

Originally Posted by mjealey (Post 11273729)

Yeah and I admit I like to twist mine pretty good. I run them all 250+ and some 280. The track we ran on was super dusty and huge this past weekend! It was the second time I have been there in the past month so it did it in. A big 150 ft. straight with a sweeping turn before it to build up speed in arid dusty conditions probably did it. Upon further review of the engine it did suck in a little dirt but very little and piston sleeve look ok. I think we caught it early and no damage done to it.