MGT faster in reverse all of a sudden??

[RSX420]

I've had a MGT for a while now, great truck! But recently I've noticed a slight drop in low-end punch, but even more of a drop in top-end. Almost seems to bog when it gets to WOT just a little, have gone about 3/4 turn lean & rich with both HSN & LSN (seperately, after warming it up) giving them enough time to see a change but with no luck... But what gets me, is now it seems to be way faster in reverse, even more so then it was in forward when all was working good. Reverse dosen't bog at WOT either... Only thing I've done was replace the tranny gears because I heard so much about them, but that was before I even ran my 2nd tank through it... Almost 2 gallons through it now, and also I've had this gallon of Maxxy's %20 for a while, but didn't think that was the problem... Everything else is still stock, as far as engine/drivetrain. I also used to have an electric car, still has the same problem, that has no tranny & rear wheel drive only but thats a diff. story. Any suggestions would be great! Let me know if I left out any info. I checked all the wheels, pins & set screws, glow plug (tried cold/medium & hot plugs) everythings ok there! Thanks in advance!!

 

[jon2]

Have you ever ran it too hot? I have noticed on my old MGT it had less fuel through it and the reverse I could "Pop Wheelies" pretty funny. I had to re-tune a few times when weather changed but my performance never diminished when tuned properly. Who knows you may have an engine slowly going south. I still have a spare one that ran strong but pulled it out of to install a 24-7 pro.

Have you changed the settings, gears? You say that you changed the plugs but have you retuned for that plug?

 

[RSX420]

Never ran it hot, its always ran a really consistent 239-241... Got up to about 250 while tuning it before but seemed to be quicker at 240. I noticed the change about a week or so ago one night I took it out in the cold and I thought between the %100 humidity and about being about 40 degrees out, that it was causing the problem, so I tried to richen & lean it out slowly, but it seemed to make it worse somewhat... But after trying it again in the day it still was doing the same thing, sometimes it seems to bog down for just a sec before it shifts also, it never did that before, then it just dosen't seem like it's letting it get to the full top end. Well, might be a good excuse to get a new Wasp .26 or something! I have the stock gearing in it since before it happened 15/52. Yes I tried tuning it between 3 plugs, 2 MC-59's and a O'd-9. Also I broke it in slow also, babied it basically, but got it up to temp of course, and less then 2 gallons through it.... Thanks again & any more suggestions would be great!

 

[RSX420]

I've been thinking about it, and could stale/bad nitro cause this??

 

[jon2]

I've been thinking about it, and could stale/bad nitro cause this??

Definitely! How Old is it?

 

[vbgagnon]

If you get the forward only conversion you won't notice the difference between forward andreverse. JK All joking aside, My father's never did that, but when the enigne started to lose some compression he switched it out for a 24.7 pro.

 

[RSX420]

It's about a month & a half to 2 months, but for the last few weeks, I left it in my van, it hasn't been hot, or been in direct sunlight, but it has been really humid and moist out... I didn't think about it that way untill this morning.... Thanks again, will get some fresh nitro today and see what happens!

BTW - There was never much of a difference in forward & reverse, but this is really noticable!

 

[RSX420]

Have been out of town, and boss didn't want me to have any fun (take my truck) so I've been having withdrawls... lol Haven't got the new nitro yet, but I did open up the engine, and there's less then 2 gallons through it, but there is black stuff on the sleeve, pretty much just the top half on the outside, not sure if anything is on the piston, looks clean, alot cleaner then the sleeve, no scratches or nicks or anything, just blackness? Any thought if the "build-up" could cause my slowness at top-end mostly?? I lost the exhaust deflector also, but didnt figure that could make a difference... I have kept with the same plug type in reference to an earlier question. Ready to get back into tearing things up and would like to get the questiong out before the "nitro store" opens Also it seems like it had been getting a little moist around the bottom of the engine after running a whole tank, not much, just shiny/moist replaced fuel lines and tightned screws some.... carb is sealed... Is it normal at all, never hurt performance a while ago when everything ran ok, just was more to clean... Thanks for the help!

 

[RSX420]

Late update.. Scrubbed the bluck stuff off the sleeve, and poured in the "questionable" nitro I had, fired right up! Ran a little lean, putted around for a few minutes noticebly all power was restored... So I dumped the trash fuel, cracked open some new, and temps were at normal and everything is great, if not better!! Neighbors aren't happy, but its 11pm noise ordinance time!! Anyways, thank you all again for the help, it was the nitro and the stuff on the sleeve causing loss of some accel. and lots of top end!!

 

[TacRacing]

Sweet, do you have a picture of your truck??

Any hop-ups??

I haven't broken mine in yet.. but this weekend I am!!!