Best ATC90/110 engine mod

[HaggLE]

This is the best mod to do to your ATC90/110 engine. This will give you an instant power increase.
You will see in the picture that its a carburettor. This carb is off an XL175 bike. You will have to make a intake manifold but anyone thats even a little handy with a welder could make it. The carb is very easy to tune and with a uni filter on the end it will run like a dream. I think the size of the carb throat is either 24mm or 26mm.

This picture is from my 90 motor that is in an ATC70 trike. As you can see it fits in and looks quite at home. The engine is bored from 50mm to 55mm taking the capacity to 108cc. It runs smooth and has been together and running reliably for 7 or 8 years.

You may have to get the dremel out to match the port size in the head to the new intake manifold to get the maximum gains.

These are so easy to jet, you loosen one of the clamps, twist the carb bowl towards you and unclip the bowl. you can then see the bottom of the carb! The idle mixture screw is on the side of the carb instead of the bottom. No more burns to the knuckles whilst adjusting this.

What do you think?

[HaggLE]

Dont you americans like these motors? Dont you do mods to make them better? how come nobody has even commented on this great aussie invention? Im sure that Steve Irwin would go for it (when he wasnt feeding crocs with his baby)

[hondatrikesrule22]

Sweet! I wish I still had my 110.... Anyways, I also heard that you can use a xl175 topend on the 110s also. There was a guy on here talking about it. It had a xl175 topend, a sl125 crank, for a toal displacement of 310ccs. It could still be bored and stroked for a total of 350ccs. You ought to try it and put it in your atc 70!

[hondatrikesrule22]

And another thing, would I have to make a new intake? Why couldn't I just take the stocker and cut the end of it off?

[hondagrant]

Gday haggle looks like a good mod ,I'l drag my little 70 out on the weekend and take some pics so everyone can have a look ,cricky she's a little beauty.

[HaggLE]

XL175 top end on a 90 you say.... you dont say.

Check these pics of a motor thats in the garage. The cases have to be welded up and hav the studs moved to the correct places. Its a lot of work and it wasnt me that did this one.

Also got some other 175 bits.

[jenndnn3]

Intriguing, tho I dont have much problems with my carb on my 110, so this upgrade would not be a hot ticket for me. However, I have a couple of 63 cc engines that would love this....of course a different carb. And finding it is the key.

[HaggLE]

I have a hotted up 70 as well that has a 110 carb on it and it goes like crazy. Its 85cc (runs an ATC90 piston with bike electrics and a MONSTER cam!). These carbs give you heaps of power as well but might be a little on the big side on a 63cc engine.

[Billy Golightly]

Man you guys go hog wild on those smaller engines. Is there any full suspension frames/chassis over there too to go along with the engines? A souped up '90 motor to 350cc's in a small light weigh full suspension frame sounds like it would be awesome. Where are you still getting all these performance parts for them like the cams, ect? All of the aftermarket hop-up parts for the 90's are long gone over here.

[thefox]

I have a hotted up 70 as well that has a 110 carb on it and it goes like crazy. Its 85cc (runs an ATC90 piston with bike electrics and a MONSTER cam!). These carbs give you heaps of power as well but might be a little on the big side on a 63cc engine.

I have heard that putting an XR100 carb. on the old Honda ct70's wakes up the motors. Since the ct70 and the atc 70 have very simmiler engines I would think it would work on the atc.

[HaggLE]

Man you guys go hog wild on those smaller engines. Is there any full suspension frames/chassis over there too to go along with the engines? A souped up '90 motor to 350cc's in a small light weigh full suspension frame sounds like it would be awesome. Where are you still getting all these performance parts for them like the cams, ect? All of the aftermarket hop-up parts for the 90's are long gone over here.

The cam was an aftermarket for an XR75 or XR80 (not sure which). They are very similar except one end of the cam is a different size (the bearing). We had a machine shop modify it to fit a 70 motor.

This 70 motor is a real wild child! Its been together for 10yrs and could do with a freshen up (getting low in compression) and if we were to freshen it we would probably use a piston from a late model bike that bear better technology than a ATC90 piston. This trike will do revs in the vacinity of 15000rpm!!!! it really does scream.

The 90 motor doesnt rev any where near that but it has loads more torque and a small amount of a power over the hotted 70 motor. The 90 really could do with a hot cam and then it would really kick ass.

TheFox - Thanks for the tip, I might look into that...