Gx160 engine swap with LT420Q1?

[bizzyfinger]

Hi there, I am new here so please be gentle and use lube hahaha.

I have a pro kart with a single Honda gx160cc 5.5hp engine. I am about to take it to the track to use but I am certain that it will be under powered for my "scary ride" wish.

I have seen on fleabay some Honda Lt420cc 16hp (Lt420Q1) engine's. They look similar but I am unsure of the difficulties I will encounter.

My REAL question is;

Are the mounting's the same?
How will the sprocket fit to the new engine's output shaft, will I incur any problems if the engine is off a generator/pressure washer/whacker?

Its ok if no one is sure but any info would be great, thank you.

 

[Bluethunder3320]

no, the engine mount plate will be different.

you will need a larger 1" bore clutch for that, that can stand 16hp. these cost around $100. or you could go the route of a 40 series torque converter (1" bore) for about 250-300 i believe.


oh yeah, and make sure its OK with your track to do so. most tracks (racing anyway...) have a rule that you NEED to have a FULLY STOCK honda/clone so that no one can show up with a rocket and win every single race...

welcome to the forums!

 

[the-cyborg]

Why not just hop up the engine you have?
If you do it right, you should be able to turn 8,10,12 hp out of the engine you have, and it'll be much lighter.
Check out nr-racing.com they have tons of performance mods for the Gx160.

 

[Bluethunder3320]

you can do that^^^ but you can also hop up a 16hp......

you can dump $1k into your existing engine and get more than 16hp if you wanted.


i dont know if its more cost effective to get the 16hp or hop up the existing motor to 16hp by the time you have converted the whole drive train, clutch, motor plate, etc.

EDIT: bottom line, you can do it, but it wont be a bolt-in engine swap.

 

[anderkart]

The first thing you need to do is research if your track will allow that 16hp engine to compete. If you post what track you'll be racing at I might be able to find their rules posted online and help you out here. (or better yet, you could just go to the track and ask the race officials)


Yep the 16hp motor mount will have a much larger bolt pattern. I could probably help you find a motor mount that would bolt right up to your kart/engine.

The 16hp will have a 1" output shaft, your 5.5hp has the smaller 3/4" diameter.
The prices of 1" bore Race clutches that can handle 16hp start at around $150.

Some generator/pressure washer engines have a tapered output shaft that get smaller towards the end like this 1st pic. You wont find any clutches sold that will work on these cranks:

_____________________

You'll want to make sure your engine has a non-tapered output shaft with a keyway machined in like the left end of this crank below:

 

[mrfreyguy]

I have a pro kart with a single Honda gx160cc 5.5hp engine. I am about to take it to the track to use but I am certain that it will be under powered for my "scary ride" wish.

If your looking to fulfill your "scary ride" wish why not just buy a bike engine. Bult in transmission, more horsepower, and about 250-500 cheaper than whatever option your currently looking at. Just a thought.....

 

[Bluethunder3320]

i agree^^^

125cc lifan? i might get one for my warrior this winter.

or for insane power go for a street bike engine.

 

[bizzyfinger]

Hi guys, thank you for the excellent info! I have just been to the track and yeah it is underpowered!

Now for your answers,

bike engines are out of the question, i need to use my local track and its a no no for shifter karts of any kind. I would love to do that but id have to go to teeside (trailer'ing) and that is a little too far for me. Plus if I use 2 stroke I will be kicked off for 5pm at my track (for noise).

So, here is my option, an ebay link (i hope i can do this)

http://www.ebay.co.uk/itm/16Hp-LT42...691?pt=LH_DefaultDomain_3&hash=item3cb5dcab8b

It seems to have a non-tapered shaft.

What do you guys think?

 

[fowler]

not tapered

 

[anderkart]

Yeah that 16hp would work fine, but did you ask your tracks officials if they allow engines that large to compete?