Honda Hobbit 70cc kit

Dayton Bourassa /

http://www.treatland.tv/hobbit-malossi-cast-iron-70cc-kit-p/honda-malossi-45.5mm-313642.htm

Above is the kit I am about to pull the trigger on, reviews are good and it comes with the jet and drill tool which I think is very handy. I do have some questions that might be able to be answered as I am new to the moped world. I have read some stuff on the 70cc kits that my stock head from the Hobbit will work just fine, but I will have to buy a spacer for the kit to make sure the piston clears the scavanging ports. Any information and tips you have on these 70 kits coming from a 50, by all means I am all ears. Thank you in advance!

Re: Honda Hobbit 70cc kit

I'm a DR guy.

They are awesome if you can keep em cool.

And if you melt a piston, just sand and get a new piston.

They're so hard, like I am right now

Re: Honda Hobbit 70cc kit

Clearing the port is not your concern. Your only requirement will be clearing the head with the piston dome. If it does that, don't go any further to try and space the cylinder losing compression and bumping the port timing. Dry fit the cylinder kit without the rings on the piston first and check for clearance.

Also, I am a DR guy too. Scored them, busted them, BENT A SKIRT.. fixed it up and kept on rolling. They are hard, good word for it. Also, they for certain require no spacing.(edited)

Re: Honda Hobbit 70cc kit

Aaron Bowen /

Listen to JBOT DR!!!!!

Re: Honda Hobbit 70cc kit

I just rode my very ported DR.

Fucking love it.

Was good stock, so much better ported wide above the semibridge.

I think I got my exhsust abound 22.5mm from the top.

Still jumps onto the pipe even with race gears really quickly.

Used it on pinball, well it melted the piston on the 5th day,

But just sanded the other day and got a new piston and it's even faster than it was before.

Re: Honda Hobbit 70cc kit

Benjamin LaPlante /

DR is the best

Re: Honda Hobbit 70cc kit

Why do you say the DR is the best? Even better than something like the Athena or the Metra Kit? I've always heard those give the most power.

Re: Honda Hobbit 70cc kit

You're gonna stick it if you've never kitted before.

It's better to be able to fix it easily once you seize.

Plated cylinders are usually a one shot deal, you fuck up that plating and it's done.

Dr can make great power with a lil porting.

Re: Honda Hobbit 70cc kit

I have a DR Kit on my Express...I have an Athena that I'm going to try out on my hobbit....now in nervous about seizing it...

Re: Honda Hobbit 70cc kit

I seized the hell out of my Athena. It cleaned up with acid and honing, a new piston and it lives to this day. I got lucky that I didn't remove the liner from the aluminum. If you don't gouge it deeply it is extremely hard. It dulled a carbide bit in seconds.

Re: Honda Hobbit 70cc kit

How did it get seized up? Running it hard for a long period of time?

Re: Honda Hobbit 70cc kit

Swapped it from my hobbit to my nc/nx 50 and it ate it on the first ride longer than a mile or two on an extended cruise run. The jet was drilled and may have been lean, the exhaust may also have leaked. Smeared the piston on all sides. Had thousands of miles on it before the swap.

Re: Honda Hobbit 70cc kit

Gotcha. Well mine is brand new...here's hoping that it will last thousands of miles.

Re: Honda Hobbit 70cc kit

I was saying that mileage had nothing to do with the seizure. The kid had plenty of miles and was not being broken in, I just broke it due to lack of tuning on a new set up and I pushed it too early or too hard.

Re: Honda Hobbit 70cc kit

I see. Well...I better get it tuned right pretty quick...no pressure.

Re: Honda Hobbit 70cc kit

Dayton Bourassa /

I see all this is helpful information, except how JBOT was hard...

I have read that the DR kit is a great one, although I know for sure Athena makes a great product as they make my engine cases and parts for my dirtbike. I have no troubles with that, but the questions that are still left unanswered are ones like if I do this 70 kit, weather it be Athena, DR or whatever, what head work if any will I have to do. The reviews and comments on treatland don't help me any as I have seen both yes slight head work, and no none at all. Thanks for all the input, Im hoping and attempting to do this the right way, meaning once and once only and hope it runs like a gem.

Re: Honda Hobbit 70cc kit

DR, no head work. Athena, head cutting needed (squish band) or base spacer but that will not set your squish, will lower compression and slightly raise port timing. But, it would clear the piston.

Malossi and Polini I don't have personal experience with. I had a Polini kit for about a week but it had an issue and ate two sets of rings in mere miles. It DID need two base gaskets to clear the piston but I did not know at the time whether that was my engine or normal for that kit. I seem to have come across over the years that it is normal for the kit.

Re: Honda Hobbit 70cc kit

I like parmakits. Had one of them on a setup with a 21mm dell and nothing else, confirmed GPS at 55

no spacing portwork or machining needed to blast, but Chop and chop so that you dont melt the aluminum

Re: Honda Hobbit 70cc kit

wilfrin hiciano /

you want to go fast and reliable. this is what you want. 46.7mm so like 73cc?? best kit period. no modding needed

Re: Honda Hobbit 70cc kit

Dayton Bourassa /

Well after doing hours of looking online between treat land and 1977 mopeds I think I'll definitely pay to play with this, but I'm leaning more towards an Athena kit. The kit it roughly around a 75cc. I have hear that 70cc kits run 88 size jets which is on the rich side so I think I will end up with a 90 and have an 88 just in case. Having said this you guys that have done this 70cc kit, you have to machine your head to have the right amount of "squish" or compression. Too little and the bike won't run, too much and it'll melt down. I know I have heard of some that say "dry fit it and make sure it clears and you're all set" but I want to do this once and once the right way. I have an understanding on what I'll have to do but if anyone has a measurement on how much machineing I will have to take down on the stock head that would be appreciated. I'm sure this thread will be used time and time again for others trying to do this, rather than "winging" it on the head machining.

Re: Honda Hobbit 70cc kit

Quite expensive for a first (disposable) kit.

The Athena is just under 71cc.. And if you run an 88 jet in that you will have a doorstop in 10 min.

Do you see why we are saying that it is not a jump in with both feet kind of thing? You just in your own words showed that you can't just pay and play.(edited)

Re: Honda Hobbit 70cc kit

No offense, but I think you're making a mistake.

Athena with the stock carb?

You are gonna run so fucking hot. But good luck!

Re: Honda Hobbit 70cc kit

wilfrin hiciano /

athen kit will do fine on stock carb. i run it on my nu50m. 70cc athena kit. stock 50cc head. as long as the carb is tunned correctly you should be just fine

Re: Honda Hobbit 70cc kit

Dayton Bourassa /

Okay not to step on any toes I guess, but if I do all my homework and the correct machining to keep the same compression ratio as stock, I should be in the ball park to run the correct numbers and temperatures. The Athena is slightly larger than the normal. My mistake it is just a hair over 70cc. If everything is done right there is no reason for me to be consuming parts and internals like some say. I know they're cheap, but if I have to do it 4 or 5 times it wont be. To the ones that are consuming internals, you might have something off of slightly wrong. Like I said I am not here to step on any ones toes, all of you have more experience with these mopeds than I do. I am just trying to get some input from the ones that have done this before. Im putting the stock kit on so I can measure the squish. If the stars line up correctly I will have the head machined the way I want giving me my 6.5:1 compression ratio. Any higher and ill melt the piston, lower and it will ave trouble running. If anyone has any more input I am all ears but I don't want to have this turn into a troll fest. Thanks

Re: Honda Hobbit 70cc kit

You can do everything right and melt the piston.

Jetting is different for each bike and where you live.

Running a 12mm carb on an Athena is just dumb in my opinion.

Gotta feed a kit

Re: Honda Hobbit 70cc kit

No, the Athena is A LOT larger than stock. Also, it has actually not too much to do with displacement as the cylinder even in a 50cc configuration would put out many times the power and heat as stock. The compression ratio is much higher and it is not an issue of machining. Most of us did it by hand with dremels and racquetballs for Christ's sake.

The stock kit does not HAVE a squish. Not one that can be used for reference anyway. See that is where you are giving me the impression of doing it wrong. You think you can measure all the stock parts and that'll be "ok" and it won't. 6.5:1 compression will require so much head material removed or so much spacing that you will not actually have a squish band and will be losing a huge part of the reason there is performance in general. In that case get the cheapest kit you can, because it isn't going to make dick for power anyway.

Forget about trying to modify what is there and consider it to be making something that never was. You need to know what a squish band is, how it functions and how you would like to make yours. Every one is different and every one will have different results.

Re: Honda Hobbit 70cc kit

wilfrin hiciano /

you need to stop worrying about what is not there. get the athena kit. put it on. use your stock head, and tune the carb. the bike will idle and give you 40 mph. hen upgrade the carb. tune it and go from there. one thing at a time. compression is a thing of preference. there is no set number everyone is trying to reach. read about it then you'll see the effects of a high and lower compression.

Re: Honda Hobbit 70cc kit

^This guy is funny, the head physically will not fit.

Re: Honda Hobbit 70cc kit

What is someone losing by using the base spacer instead of machining the head with the Athena?

Re: Honda Hobbit 70cc kit

Compression, higher port timing, no squish band.

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