2007 Roketa "Project" - Looking for Some Advice

[Ebuddy]

The boss (wife) recently let me purchase a
"project", a 2007 Roketa MC-30-150. I got it for a song and I knew there were
going to be issues so I thought I'd pose a couple of questions here and if anyone has the
time and the answer, they could do so. ;o)

The skinny on the scooter: It hadn't been used in over 2 years, but was kept in
an underground, heated garage. I knew it would be a long road before I could
ride it on the open road.

It starts and runs, but dies when it's warmed up and at idle. I cleaned the
carb once (and flushed the fuel system), but I think I'll do it again. Things
I've done so far:

* Changed the oil
* Changed the crankcase oil
* Flushed/filled the brakes (needed a new front master cylinder)
* Taken apart and cleaned the carb.
* Flushed the fuel system
* New rear tire

Things I have yet to do:

* Replace the valve stems (rear tire won't hold air)
* Replace the kick start gear (appears to be stripped on the inside)
* Replace the spark plug
* Adjust the valves (if cleaning the carb again doesn't help my stalling
problem)
* Replace the gaskets on the oil pan cover

The last one is the issue I'm trying to address. The gasket is shot. It leaks
pretty bad when the engine is warmed up and I can see it leaking from the
gasket. What I can't seem to find the answer for is that my scoot has the "B"
variant of the GY6 engine (BN157QMJ). I understand that there are quite a few
parts that aren't compatible with the "standard" 157QMJ. Different web sites
say different things. So, long story longer, the question of the day is whether
or not a long case GY6 gasket kit will fit my "B" engine.

Any help anyone could offer would be greatly appreciated! Thank you! =)

[techie610]

First, Welcome to the site. :)
You should enjoy the new scoot. Its a good bike.

How familiar are you with the GY6 engine?
Your problem is more than likely the valves.
Readjust the IN. to .003 and the EX. to .004.
Also, check to see if the plug wire is good.
As for the gaskets, jet get some material from the nearest Auto Parts store, and cut your own. Cheapest, simplest way. Just don't forget the oil galley. lol
What oils did you replace it with?

[Ebuddy]

Thanks for the reply!

I'm pretty much a noob when it comes to small engines. My first scoot, was a Geely 50cc so I did a LOT of learning! I don't mind though, I enjoy the learning and it takes my mind off of other things.

Motor oil was 10w-30 synthetic and gear oil was 80w-90. To be honest, I've not run it much and after I get done with the crankcase gasket and the valves, I'll probably change it out again.

[techie610]

Everyone starts somewhere.
My start was on the side of a back road in the dead of night. Not too cool.
I know exactly what you mean by easing your mind. Scoots started as a learning toy, then a hobby, and now its a passion... and work.. -_-

Have you gotten it to stay running yet?
Something to try, when it starts to die off, give it a shot of Ether.
If it helps it a little, check your vacuum lines and intake fold.

But, lash the valves first..

[Ebuddy]

So this weekend I'm taking advantage of Father's Day and aim to get the scoot completely up and running. I will have to remove the engine to get to everything but my goal is to finally get to the items I listed above. I will report back. =)

Hopefully, by the end of the weekend, I'll have my "daily driver".

[Ebuddy]

Well...not everything went according to plan. In fact, almost nothing did. LOL!

I did finally get the motor off – THAT was an adventure. I also got to the oil crankcase (removing the stator wasn’t much fun). Unfortunately, it took me all day.
Here are my questions:

Since I have the motor off, does it make sense to replace the belt? I think it does because it looks like you have to remove the engine to do so.

The second question is the gaskets. My local auto-parts store didn’t have material per se. Instead, they recommended this high temperature silicone gasket material that you apply like caulk. Any opinions about this or since I have to wait anyhow should I just order a gasket kit?

[blueboy5000]

Yes order a gasket kit. Order an engine oil seal kit as well.

Why did you have to remove the engine? 99% 0f all repairs to gy6 bikes can be done with the engine in the bike. I have never removed an engine to replace a cvt belt, perhaps you should research and familiarize yourself with gy6 engines BEFORE continuing to work on this bike, as trying to learn how it works by dis-assembly is a really, really bad plan.

I very confused about why the engine had to be removed at all, as you describe a carb or CVT issue, not valves. If valves were the problem, it would most likely not run at all, and be very hard-starting when it did. I'm willing to bet you have an issue with your decelerator diaphragm or some other minor carb issue. Also why did you remove the stator?

[Ebuddy]

Well, the more time that I spend with it, the more I wonder if one of the previous owners (I am the 3rd) didn’t do something to modify the scoot, the engine or both.

I removed the engine because I needed to re-gasket the oil pan cover (it was leaking – took me some time and patience to track down but it was pretty obvious). This necessitated removal of the stator, which would have been necessary anyhow to replace the gasket. Also, I tried removing the CVT cover with the engine mounted (so that I could confirm the belt size), but it was obviously (and I fought with this for about an hour) bumping up against the frame (toward the front) such that there was just not quite enough clearance to remove the cover.

I also wanted the chance to do a thorough cleaning/inspection of the motor and CVT assembly to make sure I wasn’t missing something else.

The bike has, 3,777 miles on it and I believe it to have been poorly maintained by the previous owner and everything I’ve read has indicated that a valve adjustment should be done. So… valves, oil pan gasket, belt, spark plug, inspection (and oh yea, the kick start needs to be replaced) – I figured that all that work could more easily be done on a removed engine.

I’ve kept careful track of everything so I don’t anticipate any issues with reassembly and reinstallation of the motor. If I get into any really nasty trouble, my neighbor’s a gear head (who has been unofficially supervising) who’s resurrected a couple of motorcycles, not to mention cars. So I have some cheap expertise, should I need it. ;-)

So today I’ll be ordering a belt and gasket set.

[Jaybird09]

I'm gonna have to be honest with you here. Ditch the Roketa I have had to many and everything single one breaks down all the time. I had one that left me stranded more then once. If you own a Roketa then you have to know how to fix them. Sounds like you've already done a ton of work. How is the volts coming off the battery? Replace all the fuel lines and filter. Order a new carb, 23mm is what I had on mine. Good luck brother

[bhinch]

I have a 2008 Roketa MC54B 257cc and it has been a great scoot for 10 thousand miles. It is just a machine and will require maintenance. Better scoots just require more money to purchase and no matter the price, will need attention. Life is Good....

[Swordsman]

DISCLAIMER: the closest I've ever come to working on a scooter was sitting on the seat at a dealership.

BUT, with all the reading I've done, seems to me something is horribly amiss if you can't get the pulley cover off without removing the whole engine. Belts and sliders/rollers are all wear items, so they should have relatively easy access. Makes me wonder if the engine has already been replaced....?

~SM

[Ebuddy]

Well, my hunch is that the motor was replaced. I *think* that the scoot originally came with the “standard” 157QMJ but mine has the B-variant. In reading about the differences, it appears as though the B has an ever so slightly deeper variator/clutch cover which would explain why I can’t remove it when the engine is on the bike. Perhaps next spring I’ll “spring” for a new motor….we’ll see.

At any rate, after removing the engine I re-gapped the valves (.003 intake, .004 exhaust), cleaned and re-gasket the oil pan, changed the spark plug, cleaned off all the accumulated leaked oil and road grime, and cleaned out the CVT case. The belt was still 20mm and looked almost new so I left that in. The rollers will have to be replaced at some point, but I’ll leave that to be a winter project – I’d rather just get ‘er on the road.

Once I got it all back and assembled, the scoot started right up (no more oil leaks). The problem now is that it starts and runs but won’t stay running and it dies the moment I give it gas. I ‘ve cleaned the carb 3x (using high pressure brake cleaner and pushing wire through every hole), checked the diaphragm for holes and triple checked all vacuum lines and replaced all vacuum and fuel lines. It’s definitely getting fuel. I *think* that the problem is the auto enricher. Here’s a summary of my findings:

Auto enricher on and connected – Great start up but loses idle after 10 minutes and then after about every 2 minutes upon each, subsequent start up. Dies with more gas.
Auto enricher on but not connected – Great start up, great idle, dies with more gas.
Auto enricher bypassed (gasket material to cover all three holes) – Won’t start, won’t run.

So my hypothesis is that there’s still a small blockage/vacuum leak in the carb itself. The auto-enricher masks it, but the carb still can’t get enough fuel.

At any rate, I gave up and bought a new carb/auto enricher. It should be arriving any day now.

The saga continues but hopefully I’ll get to ride it before the snow starts blowing here in MN. ;o)