QA 50 engine swap.

[Littlebear]

Hello guys,

I was recently lucky enough to obtain a couple of free mini's from a friend. One is a 1975 Honda QA 50 and the other is 1971-72 Suzuki Traihopper. Both are very complete. I will post a photo soon.

Today I got the QA 50 running and rode it for a bit. It smokes like a chimney and definitely is low in the power dept. I know I could cheaply rebuild the 50cc that is in it, but was wondering if anyone here has done the Lifan 125cc 4-speed conversion or another pit bike motor? The Lifan option looks very tempting.

I also read on another forum that the Lifan conversion requires fabricating new motor mounts, removing the factory mounts and welding on the new ones. Not a problem for me to do myself. I have found some info on the web about the QA but have not seen many for sale. The Z50 seems much more popular and abundant. Just wondering if I should'nt be thinking of cutting into the frame at all if it is rare. Thoughts?

As for the Trailhopper........ Soaking in lots of penetrating oil right now. All cables and front wheel seized.

Any advise would be mucho appreciated. Thanks.:smile:

 

[Littlebear]

Here are the two bikes. The price was right. :smile:

 

[bruces]

I have done several lifan ,zongshen ,and my favourite the piranha 140 ,and have been happy with them for what I got .The qa does not require any mods to the motor mount ,the trail 90-110 bikes have a slightly different lower mount location but the 50-70 cc bikes are good to go .The qa has a weak transmission with second gear being the usual problem ,so if you want to ride the bike a swap makes sense to me even if it’s just to a z50 engine ,which gets you another gear .I typically have about 20 minitrail s in my shop at a time and I do not see any great value in the qa ,in fact it’s the only one I rather not mess with as they tend to fetch very little compared to the rest .I sell my bikes to dealerships mainly and I like swapping in a clone engine so the bike can be ridden and enjoyed ,and I rebuild the original engine ,crate it ,and include it in the package .
I have never had a trailhopper in my shop ,but have restored and resto-modded many rv90’s ,and have swapped in Honda clone engines in a few which made a fun street ride .I know if I owned the trail hopper ,I would be stuffing a piranha 140 in it if I could .

 

[Littlebear]

Thanks bruces,

I will definitely go with an engine swap. I will check into the piranha. With this bike being semi-auto, if I go with a manual clutch, is their anyway of switching the rear brake to a foot pedal that you may know of? I have been searching a bit more about them and as you said they do not bring the money the z's do, so I will plant a new motor in it and keep it around for friends and (beginners) to ride. Probably would be fun with the 140cc in there. Thanks again.

 

[bruces]

I do not know of any pedal conversions for the rear brake ,and not really sure I would bother figuring it out myself ,although z50 parts would be how I would do it .The 140 engine is probably the best value per dollar ,lots of snap yet relatively inexpensive ,and after installing a few dozen I have yet to have any issues with them .They might be a bit more than you want or need for the qa,and I am thinking a 110 semi auto might be a very good choice for that bike ,

 

[Littlebear]

Thank you for the replies and info bruces. I decided to go with the Lifan 125cc semi-auto 4 speed. I agree with that you the 110cc would have been a good choice also. My son had one in quad years ago, no problems with it at all. I went for just a bit more due to living at high altitude. Just over 8000 ft at home and the bikes sometimes see 11-12,000 feet on the trails. There is quite a power loss due to altitude. My guess is around 20-30% loss. Anyway, parts are arriving already for the transformation............. Thanks again.:smile:

 

[Littlebear]

Finished the resto-Lifan 125cc QA 50 conversion today. Took the bike out for a few break in runs and all went well! Little wheelie popper! :smile:

 

[shadowfocus603]

Love it