Post by Trigger1212 on May 1, 2018 22:43:12 GMT -5
Hello All,
First time posting here, VERY nice site! I was on another forum that was less mod friendly and one of your members PM'd me and suggested I check out this site for more active technical/mod questions. Glad I did!
So here is the deal, I'm a mechanical guy, can work on most anything and understand engines, ignition, fuel issues. Once upon a time an automotive technician and have been a factory rep for the last 27 years.
Been snooping around in old threads to dig up as much as possible before asking questions, at the point now where I need some advice on things I could not find.
I feed like a piker asking about this after looking at your fast 2 cycle scooters but here goes anyway.
Daughter is moving off campus next year and was talking about picking up a used scooter to make the commute easier. I started snooping around an ended up buying a 2005 Honda Metropolitan II from a co worker for the princely sum of $300. Unit has 1,981 miles on it, great shape physically but had sat unused in a garage for 5 years.
Just before buying it I found out it was restricted to 25 mph. Restricted? Can't be too hard to correct that right??! Holy moly, I cannot believe the engineering they put into restricting this, wow.
I did purchase the Tech manual before starting the derestrict project.
Before I got it running I pulled the carb and gave it a good chem dip clean, replaced the float, gaskets and installed the Met I shorter spring. While the carb was off I removed the intake restrictor. Looked in the tank and was surprisingly clean in there, drained all old gas out. Replaced the fuel filter, stuck the hose from the fuel pump in a cup of straight sea-foam and ran a bunch through there, let it set and then ran some more through. Then flushed with gas and tested delivery rate and passed with flying colors.
Installed a new AGM battery and put it all back together and hit the starter, fired right up and purred like a kitten at idle, but could NOT get it off idle. As soon as I cracked the throttle it would die. Scratched my head on that one for a while then realized it had not reset the TPS data. Went through the process, but the head light would come on, turn off but never come back on like it was supposed to. Tried to disconnect the battery power to reset ECU, disconnected ECU, same with TPS, all to no avail, would not reset, crap.
I had found a MET I ECU (GET-67) on flea-bay for $79 and the guy threw in the wiring harness. So I installed that, switched the power wire one slot over to get power to the ECU and tried to reset the TPS and it worked like it was supposed to. Making progress!
Started it up, idled fine as soon as you moved it off idle it died, just like before, WTH? By then it was late and I was a little po'd so went to bed. Next morning I started it back up and started shooting starting fluid at all the gaskets looking for a vacuum leak, none found. Rolled on the throttle a bit, a little bogging around and then it started to rev up. Nice, it was working! Maybe a piece of crud broke loose and plugged a jet and finally fell away, who knows. Don't care cause it's now running fine.
Mods so far are 1. restrictor plate removed 2. Met I carb spring, 3. GET-67 ECU installed (different advance curve and higher rpm limit?)
Took it for a spin and now does 27 mph before the limiter kicks in, a 2 mph gain.
Installed a Polini variator, belt was in spec so no need to change. Polini came with two sets of roller weights, One was a bit over 6 grams, something like 6.2 and a second set that I believe was 5.6 gram. Originals were right at 6.0. Put the heavy weights in and hit the road. On flat surface with no wind got to around 36 MPH, very nice improvement but as soon as there was any resistance, wind/incline speed dropped off quickly and the motor was very doggy.
Went back and put the 5.6 gram weights in and another test drive. Now when perfect conditions can still hit 36 mph before limiter kicks in, and not as severly affected during winds/incline. In stiff wind/incline will do 30-31.
Please with results so far but would like to take it a bit further.
As far as I can determine I have 3 more options for additional speed:
1. New cam; in my mind this is the primary limiting factor now as the engine just needs to produce a little more HP to take advantage of what the Polini has to offer.
Question: Does anyone have experience with installing the Met I cam in a Met II? Are the results worth it? Is there a better cam option than the original Met I cam?
2. New CDI, mainly for the elimination of the rev-limiter. I looked at the ignition thread by 90GTVert, very informative! Looks like the CDIs tested started to advance slightly sooner than the stock ECU but they all had pretty much the same over all advance over about 3,000 rpm. I don't want to make it harder to start so a bit concerned about the CDIs advancing too fast as shown in the video. Any recommendaions considering my main objective is the elimination of the rev limitation, not looking for additional advance?
3. Final drive gears; this would probably be worth a 2-3 mph boost but unless I can get the engine producing more power it would not be worth doing.
Not trying to make a racer here, just trying to get it up to Met I standards, doing a solid 36-40 mph with 33-35 on modest hills/wind.
Appreciate any advice, thanks in advance!
Cheers!
Trigger1212
Semper Fi!
