robtangie

My Feedback: (2)

Stumbled upon a Tmaxx classic with, what I was told was a 2.5R engine. As I think I've learned, is actually a standard 2.5... I'm new to the nitro engine r/c's and looking to acquire all the knowledge I can prior to firing it up and really messing something up...
So let me start at the beginning... The 2.5 was a recent installment and needs the throttle conversion kit (which I ordered) as well as some other odds and ends like skid plates. I'm currently waiting for parts but planning to tear it down to the frame and do a complete cleaning, fixing and a bit of a rebuild during the winter months... Using this time to learn all I can about these trucks. So you guys can expect to see many questions for me in the coming weeks.
I'm wondering what the difference is between the 2.5 and 2.5R engines... As I search for parts I find I can easily find a replacement piston and sleeve for the 2.5R but find no listing for the 2.5... Are they one in the same?
It also came with a 20% fuel and a buddy suggested I use no more than 10% in it... Claimed I would surely burn the piston with the 20%. So I'm looking for some opinions and know how on that as well.
Again I'm new to the whole nitro scene as well as the r/c trucks (I've flown helis for years) so be gentile.
Thanks,
Rob.

scoobs92

ive had both the 2.5 and 2.5 r and there isnt much of a diffrence besides the sightly bigger head and maybe a tiny bit more power if even noticeable

Snook Man

There once was a slight differance in the porting of the 2.5 and 2.5R.
Now the only differance is the cooling head. The 2.5 is silver cast aluminum and the 2.5R is a blue machined head.

All other components are the same, so if you order parts everything will fit.
20% fuel is fine...I've run 33% in them with no problems. You can burn a piston and sleeve just as easily with 10% if your tuneing is off.

robtangie

My Feedback: (2)

Thanks for the quick input guys... Upon closer inspection and through reading other post I think I actually have a first generation... But here's a bit of a stupid question... I notice in a lot of pics I see (plus mine has it too) there is a zip tie attached to the filler cap on the fuel tank... What the heck is it on there for???
Thanks again,
Rob.

cmerritt

it's so that when you have the body on, you can easily grab the fuel cap to pull it open. It's acts as a pull handle to open the tank easier.

Snook Man

If you had to order the throttle bell crank kit you most likely have the 1st gen Maxx (Narrow Maxx).
Does the engine you have have a rear or side exhaust? The 2.5's are rear and needs the correct header to do the conversion. The .15 is side exhaust.

Also after you do the tear down thats a good time to drill the chassis for the throttle bellcrank post.

robtangie

My Feedback: (2)

Yes I believe you are correct and it is the 1st gen Maxx... The engine is a rear exhaust and the kit I ordered comes with the extended curved pipe and header. Found it at A Main Hobbies- http://www.amainhobbies.com/product_...25-Upgrade-Kit I seen the 1st gen referred to as the "narrow" before. How much narrower is it and what do I need to look for or know when ordering any suspension parts I may need in time to come???
But thanks for the heads up on on the header and pipe,,, I'm not always on top of stuff and appreciate the input.
As for the zip tie on the fuel cap,,, thanks for that info too... I'm sure there will be many silly/dumb questions to come and I appreciate being able to get quick and reliable answers.
I did also order an owners manual when I ordered parts,,, it too was for the 2.5R which is some of the reason I needed the 2.5/2.5R clarified for me... I also discovered that my LHS (20 miles away) carries a complete line of Traxxas parts and supplies so that is a bit of good news too...
Thanks Again,
Rob.

Andy2108

My T-Maxx originally came stock with a 2.5 engine, blew that so i replaced it with a 2.5R from the shop.  Only difference I can tell is the 2.5R has a Blue head, witch I think is cooler looking.  Otherwise their the same.

robtangie

My Feedback: (2)

Thanks for the info and input guys.
Regards,
Rob.