gphil

Have a used engine that has some fins on the left front missing. Not much just a notch. Will this adversly affect cooling? My guess is no but asking the pros again. Got to put some bearings in it and possible a carb. Has a OS carb on it now.. Still that would put it well under the cost of a new one. Standing by for input. lol gphil

JohnBuckner

My Feedback: (1)

No I do not beleve a notched fin or fins unless major portions of multiple fins are gone would affect your engine, I still have two TT .61 pros in use and one on a warbird pylon ship and both are still serving well after around fourteen years of hard use.

John

gphil

Thanks for the advice guy.  Need to put bearings in it and I guess another carb and that bad boy will be ready to go.   I just do not know if the OS carb would work or not.  Seems large enough but then again mismatched parts I don 't like.     gphil

jester_s1

As long as the carb fits in the intake and will seal up it will work. The engine doesn't know who made the carb.

gphil

I was thinking that maybe the needle valves could be different as in different size seats etc.     So what you are saying is a .61   .60 engines pretty much are the same etc.  Well good you fellas know and it will save money.  Thanks   gphil

Gray Beard

My Feedback: (-1)

A fin missing or broken isn't any problem. The PRO series are good engines, I liked them every bit as much as OS. If the carb fits and works use it, the PRO series engines are almost the same price of the OS carb and to replace it with a TT carb isn't worth it if the OS is working. If you replaced the bearings and carb you could buy a new engine for almost the same price. Bearings from rcbearings.com are about $15.00.

JohnBuckner

My Feedback: (1)

Yes if you have the carburator and it fits the boss then do try it. Keep in mind though just beacause a carb fits the boss does in no way mean it will work or work as well or at all. The venturi size is am important consideration with any engine and if you happen to try a carb with a larger venturi it may well not draw fuel as efficently as a stock carb or cause all manner of running problems caused by an overly large venturi.


A classic example are Perry carbs which for years and perhaps are still sold to this day with two completely different venturi's for either pumped or normal muffler pressure systems and the pump carb was vastly oversized for the pumped engine to acheve more power however that carb on a normal muffler system will never work properly and be a source of grief.


People often mess around with carb swaps however there are no absolutes and while some combinations may work others certainly will not.

Now I would normally recomend staying with the stock carb on this engine since it works well with this engine. Also note there have been two different carbs for the TT 61 Pro. The first version came with a straight needle valve, one projecting ninety degrees to the side. Later versions had the first of the TT slant needles where the main needle slanted to the rear around fifteen degrees. I always preferred these for obvious reasons and like the OS Ax series since they have copied this idea and improve on it slanting the main needle aroung 45 degrees to the rear.

These two TT carbs are interchangable. Now another note. The TT 46 and the TT 61 main needles are not interchangeable and You cannot hardly tell them apart visually. I can attest to this personally when one got switched on me and I had trouble with that engine constantly untill I found the proper needle was the issue. I beleve it was caused by the slightest differance in needle taper.

John

gphil

Yes John you echo my thoughts completely.   The carb now has the straight needle versus the slanted one.  I too like the ones facing the rear.  gphil

Steve Percifield

My Feedback: (14)

I have another thought on your engine. Don't know if you bought as is or if it's your engine. But if you bought it used, be cautious. Sometimes missing head fins is an indication it has been crashed. And if it needs new bearings, the crank might be bent. A replacement carb also tells me it has been crashed. Just check it out.

steve

gphil

Never thought of that aspect. It seems to turn freely but the bearings are grindy, shot. I'll take it completely apart and make sure on the crank. No doubt been a yard dart. Given to me. gphil

aspeed

Usually the crank bends in front of the front bearing.  If not too severe, it can be straightened and checked with an indicator.  The case housings usually break or crack where the carb is bolted on and the back of where the muffler bolts on. I usally run them anyway and try not to put money in them.(good money into bad)  I normally have a few parts motors around.  Sometimes a pressure fitting can be put on whre the broken needle was, and a remote needle used.  Even opening the broken needle a lot and using the remote.  What's the worst that could happen, you glide in, right ;-)