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Old 05-29-2008, 03:39 AM   #1
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Default vspec problem

Guys I need some help with my vspec. The engine is in a new losi 8ight roller and brokin normally without any issue using the heat sink method. The engine ran fine for the first half gallon after break in averaging normal temps. Very shortly after break in I noticed the engine was starting to hesitate and bog slightly about mid to upper rpm but would clear itself out once in the higher rpm range. However the engine will now stall out as i throttle upto midrange. On the box i get full the full range of throttle authority but on the track when the buggy is under any load the engine will only rev up to just under mid range and stall out. I have tried everything i can think of. Re tune, change plugs ( p3 hot ) check for leaks, change fuel filter and all to no joy. Now i should mention that when i do put a new plug in the engine runs normal for about 3 laps ( 2-3 minutes )then the whole issue starts over again.

fuel is 20% with 14 % oil
os p3 hot plug
stock engine with no change
ofna jp 4 pipe
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Old 05-29-2008, 03:42 AM   #2
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if the plugs are wearing out fast would suggest the engine is running a touch lean, try richening the mixture and try again.
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Old 05-29-2008, 03:59 AM   #3
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sounds lean, I had a similar problem. After the switch to 30% I was slightly lean.
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Old 05-29-2008, 07:13 AM   #4
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I'm going to throw something else out there and I'll probably get flamed for it but, I was talking with R2 from Ofna and he was helping me tune my Vspec and my P3 using a JP4 pipe. He told me to get rid of the pipe completely. According to Ofna, the pipe creates too much back pressure and causes the motor to overheat thus pop plugs. I was going through a plug almost every race weekend. Once I got rid of the JP4, the issues went away. So if you guys want to flame me, go for it. I got my info righ from the source.

The only other thing it could be is a stretched conrod or bad bearings.
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Old 05-29-2008, 07:43 AM   #5
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Hard to say, but i would suspect a lean bog. Try richening all your settings, and see if it gets better. At least you will know if your going in the right direction.
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Old 05-29-2008, 07:51 AM   #6
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Quote:
Originally Posted by stiffler297 View Post
I'm going to throw something else out there and I'll probably get flamed for it but, I was talking with R2 from Ofna and he was helping me tune my Vspec and my P3 using a JP4 pipe. He told me to get rid of the pipe completely. According to Ofna, the pipe creates too much back pressure and causes the motor to overheat thus pop plugs. I was going through a plug almost every race weekend. Once I got rid of the JP4, the issues went away. So if you guys want to flame me, go for it. I got my info righ from the source.

The only other thing it could be is a stretched conrod or bad bearings.
not flaming... i had same problem with my jp-3... and i went to a thunder tiger pipe with my new v-spec and i havn't gone through a plug yet and i'm at 2 gallons... i used to go through 2 plugs a day with my other pipe...

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Old 05-29-2008, 08:23 AM   #7
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Default pipe

Quote:
Originally Posted by stiffler297 View Post
I'm going to throw something else out there and I'll probably get flamed for it but, I was talking with R2 from Ofna and he was helping me tune my Vspec and my P3 using a JP4 pipe. He told me to get rid of the pipe completely. According to Ofna, the pipe creates too much back pressure and causes the motor to overheat thus pop plugs. I was going through a plug almost every race weekend. Once I got rid of the JP4, the issues went away. So if you guys want to flame me, go for it. I got my info righ from the source.

The only other thing it could be is a stretched conrod or bad bearings.
What pipe did you end up going with ???

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Old 05-29-2008, 08:29 AM   #8
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First Check the midrage needle and make sure it's correct. If the Midrange it too lean it doesn't matter what you do with the low end needle, it will never be correct.

Second, Your way lean on bottom and rich on top. Fatten the bottom end a full turn, bump the idle, and lean the top a hour or two and see what happens.

Third, I've been using a JP-2 pipe on my Vspec for over a year with no problems. Never tried a JP3 or 4 on it though.
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Old 05-29-2008, 08:34 AM   #9
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Obviously you will have to tune for power once the motor is running fat again.
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Old 05-29-2008, 09:08 AM   #10
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Also seal the backplate, base of the carb and high speed needle housing with either high-temp RTV or Air-Seal sealant. You could have picked up an air leak in the engine. That's happened on one of my V-Specs. Drove me crazy trying to figure out what was going on with it.
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Old 05-29-2008, 10:07 AM   #11
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Quote:
Originally Posted by nsgland View Post
What pipe did you end up going with ???

Neil
Well I run a JP2 now but I no longer run the Vspec. It died and gallon #4. I now run strictly picco motors. Either a P7R or a P3. Less money and they last a LOT longer. Had 11 gallons on my P3 before the bearings went out.
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Old 05-29-2008, 10:26 AM   #12
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Default V Spec Setup

I run P4 plug w/2060 os pipe & the 8mm "red" carb insert..
This is a great setup for any V Spec
Also always seal your engines around the OUTSIDE base of the carb and HS needle. I use Lucky 7 engine sealent you can find on TKO's site or Carolinas Rc
Good luck
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Old 05-29-2008, 10:48 AM   #13
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I ran the stock vspec with 2050, no problem at all, got all the mileage as much as in a tank......
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Old 05-29-2008, 12:15 PM   #14
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you cna't get the 2050 anymore can you?

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Old 05-29-2008, 01:04 PM   #15
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Quote:
Originally Posted by smitty2802 View Post
you cna't get the 2050 anymore can you?

-DC-

I bought it when they still had them at that time, they are hard to find now.. i still have 2 in my inventory......
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