Re: Soft Seize: what it is, causes, prevention, my

I was at the tail end of a 40 mile ride commin down hill and my engine made a very distinct sound it revved up then just locked as if a 2 ton car just fell on the brake leaver.


went from 35 to 0 in about 15 feet. rode it home fine. but the next day it wouldnt start :( just honed my cyl and got new rings and everything was peachy

Re: here you go

Frostback Ditch /

Hahaha, you had me worried there for a second Garret. I almost feel like trying this myself.........but sadly, no lathe can be found for my use.

....from ACTUALLY working on mopeds

Frostback Ditch /

WTF???? Please just try to get along. All this useful information shouldn't be ruined by childish bantering. And James G isn't ill, he's just tired.....

Re: ....from ACTUALLY working on mopeds

Quick question, i was riding my maxi today, crusing around for a good 25-30 minutes everything seemed fine, ive noticed lately that while at high rps it sounds like a clink clink clink clink over and over and over near the head. Not sure what it was/is. I don't have a lot of experience with all the mechanical side of the mopeds yet but i just kept riding. About 10 minutes later it seemed like the bike was going faster? and then all f a sudden it bogged down and wouldnt accelerate i rode it to a complete stop and then tried to start it up again. no dice. Started pushing the bike home and after about 5 min of letting it cool down i started it up again, rode about 400 feet and it did the same thing again. Does this sound like a soft seize? I'm going to run some new premix through tomorrow and hope that it just got too hot. Not running an air filter currently. Would a filter help with this? Sorry for so many noob questions.

Re: ....from ACTUALLY working on mopeds

Without an air filter, your moped gets more air than it is jetted for (unless you rejetted when you took the air filter off or when you put on whatever parts are on it), and that makes you run lean, which can cause the engine to seize or soft seize. If you want to know if it was a seize, take the top end off and look at it -- if it looks scuffed anywhere, you probably soft seized (or post pics and people can tell you if it's damaged). Dying when hot can also be your condensor going bad, though. You might check and see if you have spark the next time it dies on you like that.

Re: ....from ACTUALLY working on mopeds

Awesome, ill post pics of the piston and cyl tomorrow. Thanks for the help Linda.

Re: ....from ACTUALLY working on mopeds

The unfortunate thing about that noise that you believed was a soft seize is that well, it was a soft sieze. You almost know it in your gut when you hear that metal on metal sound dont ya? Sucks.

Some of what you said might be relevent to your next try tho - you noted that it happened when you came off wot and to 3/4. Id raise my needle and upjet.

People trying to communicate with targaped in this thread i can understand but can't you see he's way too far out there to even realize this isnt a tomos thread? That we are talking about mopeds made 30 years before his toilet? That he's totally FUCKING CRACKERS?

Re: ....from ACTUALLY working on mopeds

im about to install a kit on my sachs..... now im scared it will just seize

Re: ....from ACTUALLY working on mopeds

naw thats the best thing about a sachs, you dont have to worry about the kit soft siezing, it will explode the clutch first.

Dude if you worrying about siezing shit learn to tune.

BTW to whomever said you can do WOT all day with any kit, i do WOT all day with my metra 65. totally takes it , run a little rich up top , right before it 4 strokes, thing loves it. Its not a polini tho....


Ben Van Zoest /

I found my 'fathom soft seizes' were caused by a worn petcock, bowl ran enpty. Replaced never failed again.

Re: ....from ACTUALLY working on mopeds

Sullivan & Sullivan,llp /

yeah i can do pretty much whatever i want to my metra too. i soft seized up in Laconia last year but i think that had more to do with my cracked intake, then again the other 2 soft seizes up there were both on metra kits too.

Re: soft seize

targaped just acts like he knows what he's talking about. you can ride a stock bike all over hells half acre without seizing. even with extra load. I used to deliver papers on my 78 maxiluxe.

soft seized my metra after running wide open with no airfilter, down a steep hill, with my gas running low (mixed with a carb that sits kinda high) for me it was the RRRRRRRRRRRRUmmppphhh fump fump BANG!!! rrrrrrrrrr. popped out from the seize when it had just enough gas to backfire through a stuck ring.

added a little more oil to my mix and more gas and it started right up. was a little damaged afterwards though.

but i cleaned it up and it runs fine today

Re: soft seize

metra's are really resisliant little buggers

Re: soft seize

haha that kit is just broken in now :)

Re: soft seize

greg, how bad were the smear marks? could you feel the scoring on the wall?

Re: soft seize

yeah thats metra break in. Standard.

Re: soft seize

I noticed some scuffs on my piston but didnt see any signs of rubbing on the cyl.

This morning I filled the tank up with premix and rode it around the block 2 or 3 times with not a single problem, let it idle for a bit while grabbing my helmet and keys for the house and went outside to head to work. Hopped on and not even 100 feet it stalled. I tried to start it back up but nothing. Going to make a makeshift air filter today and possibly clean the carb. hope it works.

Re: soft seize

Looks like you barley made any contact. You should still be able to run fine with that. Unless im missing it, it looks real clean. Especially on top where the rings are. If that mark on the bottom is the only place that made contact, perhaps it was all done below where the rings even get to. If thats the case you dont need to worry too much.

Am I right guys?

I dont see any marks untill the bottom of the crank pin. If his Stroke is something like 35-40mm, that top ring wont even touch the mark that would have been left in the Cylander. And both rings look fine.

Re: soft seize

word on the street is some people run 60:1 on polinis....

Re: soft new build seize air seal 5o kit leo vince pipe

michael crocker /

hi new here iv built up a Peugeot trekker with an air seal 50 kit and a leo vince zx pipe put it all together and no start so still no compression changed bottom end seals now over 100 PSI all good still no start new fuel and fuel tap/vac pipes, i cleaned and changed around 3 carbs no start left it a couple of weeks and surprised it in to life and it spat all kinds of shit out the back it had a 74 main jet and some one said on pedparts blog this setup needs 68 jet so i changed iit to 68 and it started and ran ok after reving to clear all the old fuel drove up the road on the hottest day of the year, took her for a spin all good ctv needs tuning after a couple of minuets it died heat seized pushed it home. had a look in the Manuel and standard main jet 72 anyone know

Re: soft new build seize air seal 5o kit leo vince pipe

One comma in all that rubble indicates that you might have some idea of what punctuation is .

PLEASE , use punctuation .

Not many are going to try to decipher rambles .

Re: Soft Seize: what it is, causes, prevention, myth?

It would be best to start your own thread instead of replying to a 12 year old one.

Also, I'm sure you meant to ask a question. But I don't understand (edited)

Re: soft new build seize air seal 5o kit leo vince pipe

Plus, you gots yourself a scooter right there.

Re: Soft Seize: what it is, causes, prevention, myth?

I counted two commas and one period. Didn’t pay attention to where they were used though. I was so intently focused on the deciphering.

Love a challenge.

Who cares about what size jet anyone tells you on anything? If you don’t have an air leak, just keep up jetting until it four strokes at WOT and then back down a bit. Mess with your needle to get the mid range clean as well. Good to go.

Re: Soft Seize: what it is, causes, prevention, myth?

> Papa _ Wrote:

> -------------------------------------------------------

> I counted two commas and one period. Didn’t pay attention to where they

> were used though. I was so intently focused on the deciphering.


I gave up after the first comma and a few words .

I like a challenge , too . But , If I want to play word search , I'll find a proper puzzle that doesn't make my head hurt . LOL

Re: Soft Seize: what it is, causes, prevention, myth?

i know its stupid but running 40 to 1 and the plug looks fine can be the reason. the oil amount makes the plug look ok but in reality you are running lean. take another plug reading at 50 to 1 also for long trips and after the tune is right i add a cap full of marvel mystery oil to a gallon. do not try and tune with the marvel added just use after the tun is done at 50-1

Re: Soft Seize: what it is, causes, prevention, myth?

Overpriced Parts /

That grooving and stuff Don’t really matter That much, yeah you get more oil Gas mix Cushion but your jetting will change and you could lose power for optimum power you need optimum jetting with crisp clean jetting throughout the range,

if you’re going to compromise jetting that then you’ll have a turd slow bike!

What you need to you have to have a retarding timing Ignition for an air cooled 2 cycle high rpm engine and of course for the higher RPMs water cooled is best

Back in the day 60s-70s enduro and dirt bikes only revved like 8,000 RPM so you could run almost any timing you wanted and they didn’t seize

Timing first then jetting, if you’re planning to run more than 8,500- 9000 RPM then you’re gonna have to be able to retard to 12° Or less, If you’re running static timing/points ignition you can’t start off with low timing like 12° that unless you’re going downhill, 14-4.5° is about the lowest you could go to have any kind of takeoff!

So don’t run super high rpm set up And pipe if you can’t run a retarding ignition!

Man I can’t believe how people (I wanted to say stupid people) just keep posting this seizing stuff it blows my mind,

Learn to time/tune within rpm limits of your ignition and you won’t seize.

Re: Soft Seize: what it is, causes, prevention, myth?

I didn't know "soft" seizing existed until I heard about it here.

Only time I ever seized a motor was racing bicycles with China engines. And there was nothing soft about it. Seized one so hard it tried to blow the head off, shrapneled the piston so bad the bike never locked up, because there was nothing left but the piston pin in the jug. Blew piston chunks out of the exhaust.

My polini V1 runs 20:1 klotz, so im not worried about seizing that.

Re: Soft Seize: what it is, causes, prevention, myth?

Bairdco I found a supplier on fleabay that has the china cylinder with a steel sleeve and they are pretty good no more flaking off chrome.

Re: Soft Seize: what it is, causes, prevention, myth?

Dan (high idle) Conway /

This is a good thread topic just sayin, even for just awareness purposes.

If everyone just got a temp gauge, timed their bike properly, jetted properly and checked for air leaks, they would never seize. Ive owned/ridden the same few bikes the past few years on really long rides up mountains in my area and never seize thanks to the temp gauge. stay under 400F (385 if youre me), dont push through and you will be perfectly fine in my experience.

I have soft seized the same stock A3 engine 3 times before rebuild. then I started taking timing/ temps really seriously. glad i did... i can count on my bikes alot more.

I run temp gauges on my k star 70cc puch maxi, Tomos stock 49cc a35, and Small frame Vespa 90 (130cc)

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