trx 3.3 questions

[jasonn20]

I have been tuning this new 3.3 trx (1 gallon though it) but I am just not sure what to expect when i get it tuned properly. I currently have about 4.5 turns on hsn and 1.5 on lsn and it can become very responsive to thoddle only if I tap on off the gas but if I run it 50yards and it will do ok for the first pass then it is not as responsive the second pass ..etcc.. any pointers

It idles very high and the idle screw will not lower it enough...

I have a 2.5 truck with 3.3 but next week will be a full 4907 3.3

 

[joshman1204]

I would read through all of the tuning guides and flow charts on this site and also on extreme rc mods site.

Without knowing your weather conditions I really can't say anything about your needle settings. Have you checked the temp once it is completely warmed up?

 

[Kyleb]

Maybe it's overheating. Engines can perform good when cold( first started up) but after a few runs it can overheat and be sluggish and not perform too well. If you don't have a temp gun you might want to get one

 

[nikko508]

You shouldn't tune get a to a temp, you should get to a temp to tune...
Imo a temp gun is almost useles.
It sounds like your lsn needle is out of tune, the idle will very if you have your lsn needle adjusted wrong. First start with a proper idle gap and go from thr. Follow a proper tunning guide found on this site.
Temp gun should be used for reference only.

 

[Kyleb]

I wouldent say useless. It can keep you from overheating your engine

 

[nikko508]

When running your nitro eng you should be keeping an ear open and monitoring how its running,you should instantly know if your running to hot (lean) or if your rich. No one can say for sure what temp your eng should be running at, the same eng same tune in a car would run cooler than if you put it in a heavy truck but it doesn't mean its out of tune. A temp gun reading should only be used when precise fine tunning is needed and even then its only a reference, nothing in a nitro eng will melt even at extreme temps over 400, not saying that extreme temp is good but its not harmful.
Tunning comes with a lot of experience and should be taken seriously, but the only way to do that is by trial and error, and using a temp gun with no experience can only confuse you.

 

[Nitro4910]

It idles very high and the idle screw will not lower it enough...

I have a 2.5 truck with 3.3 but next week will be a full 4907 3.3

Needs tuned, reset the idle to 1mm then tune it.

The "Ilde screw" is only for setting the idle gap, you adjust the idle by tuning the LSN, a lean LSN will lead to a high idle & overheating.

Tune at half tank, engine warm, HSN, then LSN, then HSN if needed.
Make a WOT pass between each change of the needles.

Nitro tuning flow chart that Nikko508 mentioned.
https://www.rcnitrotalk.com/forum/showthread.php?t=60832

 

[jasonn20]

Thanks for the replies!

I found out my throddle linkage needed some adjustments for the idle problem.

I also have been eating spur gears and found out it was my clutch shoes installed wrong. I have it tuned well now and it is so much responsive with the clutch shoes install correctly. 2.5 with 3.3

 

[nikko508]

Your clutch shoes shouldn't have anything to do with your spur gear problem. It's usually a mesh issue more then a clutch issue.

 

[jasonn20]

Your clutch shoes shouldn't have anything to do with your spur gear problem. It's usually a mesh issue more then a clutch issue.

Well... those shoes installed wrong took out a brand new set of bell bearings which was locking up the bell intermitently... this is a whole new truck with these shoes flipped around.... I can not believe I have been running this brand new 3.3 engine like this.... a hard break in...

 

[jasonn20]

What gas tank would be recommended for this tmaxx cause I break the stock ones every time I run this truck (half gallon) and it is getting anoying.. $14,$14,$14,$14 ...

not sure if I sholud start a new post or not... ?

 

[Bkyd Basher]

What gas tank would be recommended for this tmaxx cause I break the stock ones every time I run this truck (half gallon) and it is getting anoying.. $14,$14,$14,$14 ...

not sure if I sholud start a new post or not... ?

How exactly do u keep breaking them?

 

[dub c]

when in doubt.... richen the Low side needle.

 

[2revo1maxx]

Nitro 4910 gave you some good tuning advice, and do a search on the "ofna violator tank"....it's the best option available.

 

[jasonn20]

Thanks for the replies, I have it tuned in well it was some problem with the clutch that was binding and overheating the engine which gave me trouble tuning. I ordered a bunch of parts for a 4907 truck but forgot to order the screws... still having fun with this 2.5 with 3.3...

The spur gear problem seemed to be loose/striped screws on the trans.

I bash this truck and so does the kids next door and my neices and nephews... ting into the medal telephone poll several times then carwheels 4-5 times in air before it lands type thing.. if it breaks I want it stronger...