38 year old beast lives! a little....

[reedy17]

Alright so the past couple days my project was to get this 1973 ATC 70 running again, as its been stored in my uncles garage for probably 15 years untouched.. well, it took a new coil, complete rewiring, new points, condenser, some carb cleaning, and just too much crap, and today for the first time in 15 years it started... i rode it down the road and back, and im having a few problems that are sorta stumping me. First things first, in 1st gear i have little to no pick up, granted im a big guy it has like nothing there, and once it starts revving it goes ok, a little shaky and such but it goes, then hits the point where i need to shift to second, so i do, and it goes into second and bogs way down then once it starts getting up again it goes, 3rd gear has almost nothing, its like at low RPMs theres like no power what-so-ever, and has little to no pickup in any gear.


-not to mention i cant get the shift lever to tighten up all the way and its pretty annoying!


Im thinking it could be some carb problem as that was the biggest problem getting it running is we were having trouble getting fuel through the carb into the firing chamber. it would come up through the bowl but be bone dry up top, we cleaned it as much as we could, main and pilot with carb cleaner, the rest was just kind of blown out.


Any tips would be awesome! need more info just ask

[Xpress]

I am having that same issue with my 110 right now. Almost no low end power, but once it goes, it starts moving. 3rd and 4th gear I can't ever use, not enough power. I am thinking it's something to do with the carb, or possibly an air leak. Does yours idle at least?

[reedy17]

Yes mine idles, and rather high at that, i havent played with any of that yet, its a lil smoky and high idle, but im thinking mine might have something to do with either the valves not being done right, or for sure the carb, i have no clue what else it could be.. im hoping its nothing to do with the gap on the point as id hate to tear this thing down again, it was a nightmare..


edit: or my air/fuel might be significantly off, i dont know for sure

[Vealmonkey]

I don't know if you have checked your front axle bearings, rear axle bearings or your chain, but they can kill the performance of a trike that has 9 or 10 horsepower, so check those out as well. And to adjust the points, you shouldn't have to pull the flywheel. Points gap, valve lash and static timing and running timing are very important. I hope you changed the oil and adjusted the clutch mechanism as well. And you know that there is an oil screen inside the clutch cover I hope as you don't want to starve the oil pump for oil. Make sure also that your rear brakes aren't dragging which will slow you down as well. It has to be a harmonious system for all to work correctly. Best of luck.

[reedy17]

I don't know if you have checked your front axle bearings, rear axle bearings or your chain, but they can kill the performance of a trike that has 9 or 10 horsepower, so check those out as well. And to adjust the points, you shouldn't have to pull the flywheel. Points gap, valve lash and static timing and running timing are very important. I hope you changed the oil and adjusted the clutch mechanism as well. And you know that there is an oil screen inside the clutch cover I hope as you don't want to starve the oil pump for oil. Make sure also that your rear brakes aren't dragging which will slow you down as well. It has to be a harmonious system for all to work correctly. Best of luck.


well in the process of everything else we did gap the points, and valves, brakes hardly work so i dont see them being a problem, and it rolls very freely doesnt feel like hardly any resistance due to bearings.

As for the clutch nothing was done, it does jump a little when shifting from neutral to 1st and hates going back into neutral

oil is in great shape and was changed not long ago due to my uncle attempting to work on it (one of his million other projects he wont finish!)

[hillbilly 200x]

see if the exhaust is full of stuff. The bike was been sitting who know what code of made a nest in the pipe

[reedy17]

I guess that could be true haha, i just adjusted the clutch, and i guess tomorrow ill play around with the carb and see what happens

side note: how wrong would it be to just soak the whole carb in carb cleaner if i took the rubber gasket off, the floats are made of metal, would this be ok or should i stick with spraying it here and there, and soaking only the jets in it?

[Thorpe]

Rebuild your carb... I have rarely had sucess with just "cleaning" them...

[reedy17]

Rebuild your carb... I have rarely had sucess with just "cleaning" them...

Im thinking that may be causing my next problem, lack of power once the engine is warm, granted im a big guy but when i start this thing up it runs like a dream i can cruise around with decent power (now that i adjusted the clutch) but now ive come across it completely losing almost all power once its hot, to the extent where itll hardly even go, any ideas on what would cause this to happen? would it be the carb?

[hillbilly 200x]

what colour is your spark plug. I have seen lawn mower that run like this and it tured out to be an air leak some where in the intake system.

[reedy17]

what colour is your spark plug. I have seen lawn mower that run like this and it tured out to be an air leak some where in the intake system.

well i dont have an intake system i have an open air filter on the carb, as the 73 air cleaner set was a nightmare to try and find and this one didnt have it on there, so i ran an open filter, but aparently it was having this problem before it broke down years ago where it would get hot and lose the power, and when it gets to that point it wont even get moving unless you get off give it gas to get it rolling then get on, or give it a push, its a dramatic drop in power

[hillbilly 200x]

I mean intake system as your intake manifold and carb. Not runing an air flitte may not help you out aswell because you are giving the engine to much air and not enought gas to have a proper mix. just my .02

[coolpool]

Does it act the same way in low range too? I don't know how big you are, but if the engine is a high miler it just might not have enough jam to get you moving easily in high range?

X 2 on checking your chain lube/adjustment

[bigworm626]

Stick with Thorpe's advise, rebuilt carb is the best way to go. It wil be a well spent $25.