Upgrading from a 5 hp to a 13 hp engine. Transmission questions!

[sse1478]

Hello,

I'm going to upgrade my single seater go kart which came with a 5 hp Robin engine to a 13 hp Greyhound engine from Harbor Freight. My main concern is the torque converter which is a Comet 30 series (rated for a max of 8 hp). Considering that I am the primary driver, I was wondering if i could keep my existing torque converter if i was easy on the throttle i.e. not flooring the go kart when it is stopped etc. I was also wondering what the weak point in the torque converter is (the belt, driver, or the driven). Both shafts are 1 inch, but I am unaware if they are in the same x y position. Are their standards for the placement of engine shafts, or do the vary by engine seize and manufacturers? Any information would be greatly appreciated as I have never done anything like this before.

 

[t0x1k]

Well, 8HP and up has a 1 inch shaft, so a new driver is needed.
Plus a new mounting plate for the engine therefor both may not line up. The 11hp and 13hp blue clones are HUGE! twice the weight and size of a standard 4-8hp engine.

Is it a cast aluminum or steel plate? or like that flat plate that goes under the engine?

The belts the weak part. Apparently comet underrates their stuff.
I'm going to buy a TAV2 for my 11hp clone.

 

[sse1478]

Well, thanks t0x1k for the reply. That is an interesting point about the shaft seize being 1 inch and up for 8 hp engines because my 5 hp Robin Subaru has a 1 inch shaft. As far as the engine mount is concerned it is a flat plate. I measured the mounting holes on the new engine and they appear to the same as the current 5 hp. My concern is the shaft location on the new engine compared to the old engine. So i was wondering if i could make new holes in the existing plate in order to get the proper distance for the belt by moving the engine forward or backwards. My kart is a 6 year old Manco Dingo.

 

[vandancouver]

if you can drill new holes in your old mounting plater to get it to line up (and still keep the engine on fully) so do it.

 

[toofarnorth]

if your driven pulley is on a jackshaft plate like this one http://www.diygokarts.com/vb/attachment.php?attachmentid=4280&d=1247862787 I'd say the worst that could happen is being a bigger engine the crankshaft could be further away from the pulley, in which case you would just need a longer belt. http://www.gokartsupply.com/tcbelts.htm