Monster Scooter Engine

[aero07]

New build, I just put a BMP friction drive
with a Monster Scooter engine on it.
I think the engine is the same as
the auger engine from Harbor Freight.
After I got the carb dialed in it runs
pretty good maybe 28-30mph on the flats
but as for hills it doesn't seem to have much torque.
I have a 68.5 HT that seems to have more
bottom end than it does. Can anyone tell me
what's the biggest motor I can get that will
still bolt up to the BMP 78mm clutch drum
besides the GP460 ( I read somewhere that
the 460's bottom end is lacking too).

 

[kerf]

aero07,

Is your engine broken in? Have you wiped out the cylinder plating using cheap two stroke oil (low compression)? What roller are you using?

My experience with this engine, using a 1 1/4" roller, is that it has plenty of bottom end and hill climbing ability. From the start I now use only Red Line Full Synthetic Racing Oil. Break in takes a little longer but it keeps the engine healthy.

 

[Esteban]

I agree with kerf. Another thing you may want to consider,,, the full suspension bikes usually are already quite heavy before adding the kit.

 

[aero07]

aero07,

Is your engine broken in? Have you wiped out the cylinder plating using cheap two stroke oil (low compression)? What roller are you using?

My experience with this engine, using a 1 1/4" roller, is that it has plenty of bottom end and hill climbing ability. From the start I now use only Red Line Full Synthetic Racing Oil. Break in takes a little longer but it keeps the engine healthy.

kerf,
I'm sure the engine isn't broken in yet,
I've only tested it twice. Maybe a 1 1/2 tanks of fuel
through it so far. I was just stating that it did not
seem to be much on the bottom end. I'm using the 1.25 roller and
I'm 220lbs. I could go to the 1 inch roller but did not want to give
up any top end.
I know these little engines aren't going to jerk your head back but
I was kind of disappointed. Just wanting a little more than what
I'm getting.
In your opinion Kerf, would the GP460 be any better?

 

[aero07]

Again, what options do I have on different engines that will still fit
on the BMP kit???????

 

[kerf]

The friction drive is on my wifes bike and it's running the HF engine. My chain drive is running the R460 and I had a two speed rigged up on it. When the wife was running the TLE43 with a 1 3/8", I could run off and leave her up big hills in low gear. Now with the HF and a 1 1/4", she will pull away from me.

I'm 250# and her bike pulls me up hills just fine, so the 52cc HF seems to have great torque. Several people here have used the R460 on friction drives with mixed results. Some say it works good, others say it gobbles tires. I would not use it on a friction drive because over 7K, it gets very strong and any slippage going up hill at WOT could leave your tire on the road.

Your engine should be hard to pull, with very noticeable resistance on the compression stroke. If not, pull the jug and see if you've scored the cylinder. Any loss of compression kills bottom end. I know because a month ago I wiped out the plating on the 460 and it wouldn't pull a sick wh**e out of b*d. A new jug, piston & ring and .005 copper cylinder gasket and I've got a brand new friend that I never knew before.

 

[maltese guy]

Again, what options do I have on different engines that will still fit
on the BMP kit???????

You can use a minimoto engine,it bolts on perfectely on the bmp kit.they are powerfull engines and upgrades are easily obtained... I did it and was pleased with the performance.If you choose to go this way,take into account that you have to manufacture/modify an exhaust to fit engine and you also need a fuel tank. you can see my setup on the BMP website were it says customer photos. hope this helps

 

[Esteban]

Ride it a great deal more to get it broken in. A smoother tread tire is better, too.Just pedal-assist more on hills.

 

[jim_himself]

I've used the gp460 on a friction drive and it works great for me, granted I am only 175lbs. It has worked fine with very little problems for me. I do recommend that you get a low-end performance exhaust though, i picked one up on ebay for $35, you will be amazed the difference one of these little pipes make

 

[kerf]

I've used the gp460 on a friction drive and it works great for me, granted I am only 175lbs. It has worked fine with very little problems for me. I do recommend that you get a low-end performance exhaust though, i picked one up on ebay for $35, you will be amazed the difference one of these little pipes make

Tell me more about the exhaust. I've made several exhaust for my beast and am always interested in something new. The glass pack on my 460 is going to be scrapped because I'm switching to a CVT and the engine has to turn around.

I don't want to get off topic or thread jack so feel free to PM me.