ET2 - Not starting - Time for a top-end rebuild?
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Member
'06 LX50, '08 LX50, '01 ET2
Joined: 30 Oct 2012
Posts: 29
Location: Cambridge, MA
Mon Aug 12, 2019 9:47 am quote
Hey gang,

Per some of my other threads, now that I've got the LX50s sorted (aside from one LX50 now needing a twist of the throttle to get it started instead of just immediately firing up), I'm finally trying to bring it on home with a new-to-me 2001 ET2 that I bought where it wasn't starting at all.

I spoke with George at Scooterpartsco (he's amazing!!!) and he's pretty confident that it's my top-end that needs a rebuild. Compression test was 60psi; he said it should be 110 or more to actually fire up.

Obviously I need to do that, but before I make any purchases - I wanted to check with the rest of the gang here per last-minute suggestions, as my budget is a bit strained given the LX50 and the ET2 purchases in the first place. The pressure is on for me to get the ET2 running, as I need to quickly sell one of the LX50s.

It's a stock ET2 with the 12mm Weber carb. Has about 8K miles I think, but no formal service in the past nine years? It needs some TLC, obviously. Was apparently working just great up until 6 weeks ago, so I'm doubting it's the carb. I don't believe the the previous owner was stranded somewhere, so I doubt it's a total soft-seize situation or a CDI. She just tried to start it one day and it simply wouldn't go.

After dropping in a working battery (the previous owner used the kickstart for a long time), the motor runs and sounds like it's running cleanly. The carb is getting gas; there was slight amount of gas at the spark plug after repeated starts. Again, the starter motor runs just fine, but it won't fire up at all. Haven't tried the starter fluid test in the throat of the carb.

Here's where the scooter is at per my initial repairs:

* petcock replaced (it was stuck open) and I good gas put in tank.
* brand new iridium spark plug installed with an NGK (3981) BR9EIX (good experiences with iridium on the LX50)
* vacuum line replaced
* fuel line replaced
* new clamps
* battery replaced
* starter relay replaced

Given that there was a bad gas smell in my garage as soon as I bought it, the first order of business was to make sure there were no gas leaks (I don't want a fire or to upset my neighbors with gas fumes). With the new petcock, vacuum hose, fuel line, and gas cap gasket, I think things are set there.

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2001 ET2 not starting...top end needs to be redone?

***********************

So I'm thinking the next step is to see if I'm getting spark, as it looks like I'm getting fuel.
I would think that despite the low compression, it should at least turn over, correct?

Per the top-end job, I'd love your suggestions. Per modding, here's where I'm at:

* If I have to go in and do this, I might as well spend ~$100-something and at least get a 70cc kit now (although I can't afford to also buy a 17.5 carb and a new pipe immediately.
* I don't want to regularly make pre-mix, but would rather up-adjust the auto-lube to compensate.
* I don't have either the funds or the time for major tuning right now, but would love that option down the road.
* I do want more power than my LX50, but don't need a monster scooter either. I already ride a motorcycle for days when I want to go fast. Basically, I want close to the same fuel efficiency, but more power (maybe faster?) and not needing to go to the gas station more regularly. Maybe I just need a good 70cc kit and be done with it? If so, which one?

Many thanks for fast replies; I'd like to order whatever I need ASAP and have stuff here later this week. Thanks!
Hooked
2003 ET2 (SOLD); 2004 GT200
Joined: 22 Oct 2016
Posts: 300
Location: Atlanta, GA
Mon Aug 12, 2019 11:43 am quote
I'd definitely use this opportunity to get the Malossi 70cc kit. The cast-iron one is reliable and provides a significant jump in performance. As you free up additional funds, a performance pipe will also yield significant gains (if you can get your hands on a LeoVince SP3, jump on it!). There are people who have used the Weber carb with the kit but I ended up going with the Dell'Orto 17.5mm carb as my Weber was totally shot from neglect by the previous owner. Jets might be harder to come by for the Weber, however.
Moderaptor
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
Joined: 26 Aug 2007
Posts: 37389
Location: Pleasant Hill, CA
Mon Aug 12, 2019 11:54 am quote
Re: ET2 - Not starting - Time for a top-end rebuild?
foodbiker wrote:
So I'm thinking the next step is to see if I'm getting spark, as it looks like I'm getting fuel.
I would think that despite the low compression, it should at least turn over, correct?
But it is turning over - just not starting!

Yes, check the spark. Easiest by leaving the spark plug in situ but removing the cap and testing with another spark plug.

If you do have a nice bright blue spark, then it's down to the compression - but in my limited experience it's hard to get a proper compression reading on these scoots.

My bet is that you've got a a problem between the CDI and the spark plug. Could be any one of duff cap, duff HT lead, duff coil, duff connections to the coil.

If all those check out, I'd check the CDI before rebuilding the head. Once you got it running, even badly, then by all means get the better top-end.
Member
'06 LX50, '08 LX50, '01 ET2
Joined: 30 Oct 2012
Posts: 29
Location: Cambridge, MA
Tue Aug 13, 2019 8:34 am quote
Thanks for the advice, guys.

Well, I dropped in an in-line spark plug tester from Harbor Freight, and it certainly lit up when I pressed the starter. However, still no start. I'm assuming that this means that I'm getting spark, right? Also, does that indicate that the CDI is okay?

So again, I've got fuel, spark, and I'm assuming I have air (I doubt that the scoot suddenly died because the air filter is totally clogged). I do have a Malossi air filter that I'm ready to drop in; does it need to be oiled like an LX50?

What's next? Top end? Thanks for the advice per the Malossi 70cc...likely ordering that. Do I have to drop the engine to do the rebuild?

Thanks!
Hooked
2003 ET2 (SOLD); 2004 GT200
Joined: 22 Oct 2016
Posts: 300
Location: Atlanta, GA
Tue Aug 13, 2019 8:45 am quote
foodbiker wrote:
Do I have to drop the engine to do the rebuild?
A buddy and I did mine without dropping the engine, though I read that doing so makes the job a bit easier.
Member
'06 LX50, '08 LX50, '01 ET2
Joined: 30 Oct 2012
Posts: 29
Location: Cambridge, MA
Tue Aug 13, 2019 8:46 am quote
That's good to hear; just want to keep things really simple and get back on the road ASAP.

Correct - I hit the starter button, and you can hear the starter motor working and it doesn't even fire up for a second. It's just not starting. Same with the kickstarter (which I assume from which -- you can tell that the engine isn't seized).
Enthusiast
2009 S150, 2017 GTS300Super, 2006 GT200
Joined: 18 Oct 2014
Posts: 87
Location: Houston
Tue Aug 13, 2019 9:22 am quote
everytimeidom wrote:
foodbiker wrote:
Do I have to drop the engine to do the rebuild?
A buddy and I did mine without dropping the engine, though I read that doing so makes the job a bit easier.
I cannot imagine the horror of reaching into that small space trying to compress the rings by feel alone to get the new cylinder on. Fine job doing that with the engine in place. I pulled the motor when I put on the 70 for my friend.
Member
'06 LX50, '08 LX50, '01 ET2
Joined: 30 Oct 2012
Posts: 29
Location: Cambridge, MA
Tue Aug 13, 2019 5:19 pm quote
Here's the update.

As a Hail Mary pass, I got a known and working 12mm Weber carb from my friend - who said it worked great the last time he used it. I think it had a 75 or a 76 jet. The bowl gasket had a cut, so I was able to salvage the one from mine. I cleaned both carbs while I was at it, and it looks like the jets were clogged in mine (I'm not sure how it was working just 6 weeks ago for the previous owner). My friend's carb was clearly in better shape.

It took me about 2-3 hours of cleaning the oil-caked mess that was the area around the carb and reinstalling my friend's carb...and put everything back together.

Absolutely no change.

One other possibility is using my friend's known and working OEM 50cc top end. However, if I'm going that deep in there, I'm tempted to just order a 70cc Malossi or 72cc D.R. Racing kit and knock that out all at once. If it's easy to do a top-end, and as funds are tight, I figure I'd just clean up what I have from my friend and see if it fires up.

Any last minute advice? Thanks!
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Granturismo 218
Joined: 04 Feb 2013
Posts: 5323
Location: South Carolina
Tue Aug 13, 2019 10:57 pm quote
Of course.
First remove the spark plug from the engine, grab hold of it, and try to start the bike. But call and let me know you're going to do it first, so I can use the results of that test for your personal ringtone. That's a good way to tell how strong the spark is.

Seriously, if your friend has a top end that he replaced while the bike was running, check the cylinder and piston for scoring. You will recognize it when you see it, it's grooves or gouges in the cylinder wall or on the piston. That's more than likely what you are going to find when you take yours apart.
If it's fine, you can order new rings, circlips and gaskets, and it should be good to go. From the time you install a new top end, it starts wearing down and losing compression. Typically, you replace the rings and/or piston at 8-12,000 miles on a 50cc two stroke like a Piaggio or Minarelli. It takes about 4-5 hours to break in a two stroke top end, so don't ride it like you stole it or see how fast it goes for a tank or two of gas. Stop and go city traffic is perfect for breaking one of these in. Add about two ounces of oil to each gallon of gas, in addition to the oil pump. and carry an extra spark plug or two, in case the plug fouls.

Have you checked to make sure the belt for the oil pump is intact? Usually bikes don't go from running to 60 psi unless something like no oil happens, or someone puts a bunch of mechanic in a bottle engine cleaner in the gas. They usually fade gradually down to about 90-95 and then just don't start one day.
Member
'06 LX50, '08 LX50, '01 ET2
Joined: 30 Oct 2012
Posts: 29
Location: Cambridge, MA
Wed Aug 14, 2019 7:54 am quote
You are too funny, @Motovista! LOL. After getting a shock from a spark plug working on my old /6 years ago, I have a healthy respect for proper spark plug grounding and hopefully Iíll be calling you again shortly with another re-order instead of making a personal ringtone. Thanks for all your advice and I hope youíve heard me sing your praises here on MV.

Just tested a different and brand-new spark plug not installed in the engine and hit the starter (while grounding the body of the spark plug). The was a healthy spark (I think blue), so we must be getting spark. Does this rule out the CDI from being bad?

Sure enoughÖas soon as I received an email from you saying that the last order shipped, I realized that I forgot to order a new oil belt from you. Go figure. Oil seems to be flowing when I crank the engine, particularly as I'm noticing an air bubble moving in the line. I'm assuming I'd be best off pouring some pre-mix directly into the gas tank?

Also, after we spoke on the phone, I contacted my friend and only then - did he realize that he had his original 50cc top end sitting around and he offered it to me. If it is going to be a major project to do the install (that I wonít have to go back in for another 6-8K miles), Iíd rather just go ahead with a brand-new top end (damned be the cost) and be done with it. Again, I just want this running ASAP; Iíve done enough wrenching this summer and just want to ride before it gets cold outside. Just worried as to whatís next if that didnít work, especially after dropping more money on this project.

I've gone through previous threads... If anyone knows of a video that shows the step-by-step of taking apart the ET2 to access the engine for the top-end swap, please let me know. I found Robotís awesome LX50 video (https://www.youtube.com/watch?v=eFsxTcvBlOc), but thatís not an ET2. Iím assuming itís similar, but itís not exact. I'd feel more comfortable with a step-by-step video.

Meanwhile, I've just knocked out the front brakes and am working on a few minor electrics while I wait...
Member
'06 LX50, '08 LX50, '01 ET2
Joined: 30 Oct 2012
Posts: 29
Location: Cambridge, MA
Fri Aug 16, 2019 6:46 am quote
Hey guys,

QUESTIONS:

1) My next step is to try to add a teaspoon of oil with the spark plug removed and then see if the compression goes up to 80 from 60. But what type of oil do I spoon in there? 2-stroke oil? If that's the case, then bingo - time for a top end rebuild.

2) Does anyone have a step-by-step process of how to drop the ET2 engine? I'm admittedly a bit intimidated here and not sure how to do it.

3) I gather that in the process, the best thing to do is to drain the oil tank. But how does one bleed the oil system, with the pump in the way when I put things back together?

4) Is the oil light supposed to come on at start and shut off upon ignition? I noted a very interesting clue this morning. As my clock is dead (a fresh battery didn't bring it back to life), I figured...why not check the instrument cluster bulbs?

Well, guess which light was blown out? THE OIL LIGHT. That leads me to think that the previous owner(s) in the past may have run the scoot with the oil light out...and damage was slowly done in the process. Upon a visual inspection, there's plenty of oil in the lines -- but maybe the damage was done long ago and nobody knew about it. The plot thickens!
Hooked
2003 ET2 (SOLD); 2004 GT200
Joined: 22 Oct 2016
Posts: 300
Location: Atlanta, GA
Fri Aug 16, 2019 11:13 am quote
foodbiker wrote:
Hey guys,

QUESTIONS:

1) My next step is to try to add a teaspoon of oil with the spark plug removed and then see if the compression goes up to 80 from 60. But what type of oil do I spoon in there? 2-stroke oil? If that's the case, then bingo - time for a top end rebuild.

2) Does anyone have a step-by-step process of how to drop the ET2 engine? I'm admittedly a bit intimidated here and not sure how to do it.

3) I gather that in the process, the best thing to do is to drain the oil tank. But how does one bleed the oil system, with the pump in the way when I put things back together?

4) Is the oil light supposed to come on at start and shut off upon ignition? I noted a very interesting clue this morning. As my clock is dead (a fresh battery didn't bring it back to life), I figured...why not check the instrument cluster bulbs?

Well, guess which light was blown out? THE OIL LIGHT. That leads me to think that the previous owner(s) in the past may have run the scoot with the oil light out...and damage was slowly done in the process. Upon a visual inspection, there's plenty of oil in the lines -- but maybe the damage was done long ago and nobody knew about it. The plot thickens!
1) I'm not familiar with what you are describing but I'd assume you'd want to use two-stroke oil.

2) Check the workshop manual here: http://manuals.wotmeworry.org.uk

3) Same as #2

4) Yes, the oil light should come on, then turn off once the engine is running. Your theory might be correct: the PO might not have realized the oil light wasn't working which led to the oil reservoir emptying, causing the engine to get straight gas. That would certainly cause problems leading to a loss of compression.

I'd suggest making sure the oil pump belt is still in tact while you're at it. There may be oil in the line but if the belt is busted, nothing is going to pump out. IIRC, you can see it after removing the variator. It is tiny, thin and fragile.
Member
'06 LX50, '08 LX50, '01 ET2
Joined: 30 Oct 2012
Posts: 29
Location: Cambridge, MA
Fri Aug 16, 2019 4:57 pm quote
Thanks so much for the input, let alone the ET2 manual link. That's huge!

I tried the teaspoon of 2-stroke oil...I think I successfully got in there...and it didn't seem to help much with the compression as it was still around 60.. However, this time I noticed that it didn't hold steady and slowly leaked out. So I think yes - it's really a compression issue so a top end is next.

The fact that the oil light was dead blew me away...and I'll have to really go though things once it's all back together. When I cleaned the carb area...it was all caked and covered with what was likely oil. Again, it's a bit of a smoking gun I guess and will report back. Cheers.
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