Hard or soft seize on a Hobbit polini...cant tell.

Gym-Me IRE /

Apr 14, 2009 07:00PM

Ok, while riding my hobbit thinking everything was running awesome, just mid throttle….then I hear a weird poping, like a gasket leak….then as Im going up a hill, loss of power, then, SLAM, dead…bike comes to a dead stop , not running.

I take the head off and look, I blew a hole through the meatl gasket, dont ask me how…then I look at the piston and its scored on top in 2 spots as well as the cylander…the kit was only on ite 10th mile and Im running a 95 jet with 25: 1 mix.

THe scoring isnt bad, I mean, when you rub your finger over it , yoiu cant feel it…but the thing is, after I replaced the gasket it wtill wont start! Just coughing wierd unburned gas…

SO is it possible I blew a seal, or is the scoring worse that I think…and will keep it from running…

Any help is greatly appreciated, that thing was running strong!

Re: Hard or soft seize on a Hobbit polini...cant t

Chris Rice /

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chrisr

Apr 14, 2009 07:14PM

I've never heard of a moped head gasket blowing... So your rings are loose and the scoring isn't that bad?

Re: Hard or soft seize on a Hobbit polini...cant t

King Drunky JCams /

jcams

Apr 14, 2009 07:15PM

Did you do a compression check after re-assembly?

I soft seized my old Metra kit like 3 times when it was new, and after I got it jetted right and mixed the proper amount of oil to gas, I had no more issues for about 1500 miles.

As long as there are no major scores/scratches in the cylinder and the piston/rings look ok, I would think the kit would be fine...

However, I have zero experience with the hobbit polini kit...

Good luck.

J

Re: Hard or soft seize on a Hobbit polini...cant t

R . /

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jasonf

Apr 14, 2009 07:48PM

Head gaskets can/will blow. If there are marks on the TOP of your piston, as you said, that means there was metal floating around in the combustion chamber long enough to cause some damage. How does your compression feel? Significantly lower than before?

The usual cause of blown/burnt gaskets after an assembly is improper or uneven torque on the fasteners. It's likely you had an air leak long before you popped that gasket.

How did your plug look? Was the jetting correct?

Re: Hard or soft seize on a Hobbit polini...cant t

) Cupermcnewbster ( /

boardmonger

Apr 14, 2009 07:50PM

its easy to blow headgaskets if things aren't torqued properly or you are rocking super high compression. Did you skid to a stop or did it just loose power? Are the rings ok? Is your electrical all good as it should be?

Re: Hard or soft seize on a Hobbit polini...cant t

Motobee Goode /

motobee

Apr 14, 2009 08:06PM

I wonder if that 25:1 premix was the culprit (in light of the theory about puch polinis and the 60:1 being idea to ward off seizures).

Re: Hard or soft seize on a Hobbit polini...cant t

peter /

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peter

Apr 14, 2009 08:32PM

absolutely not. honda suggests running 25:1 from the factory, there is a sticker on every hobbit near the gas tank that suggests it. this wasnt a seizure either from what he is describing.

puch polini and hobbit polini completely different.

head gaskets blow, it happens... turn the magneto over and check for good compression.. did you clean anything up or just bolt it all back together?

Re: Hard or soft seize on a Hobbit polini...cant t

Zeke /

ai

Apr 14, 2009 09:06PM

i blew a head gasket it was "fun". not that bad actually. new rings if they are mucked up bad or you feel like it

Re: Hard or soft seize on a Hobbit polini...cant t

Gym-Me IRE /

humanaquarian OP

Apr 14, 2009 09:37PM

OK, rode it home, so yeah, It runs.....

Thanks for all the resposes, but this is what happened....

1.I was running a Spree head= HEATED UP VERY HOT dont ever use one!

2. the metal head gasket had to be honed out to accomidate the piston head, Polini did not supply a head gasket

3. I cut too close to the decompression hole, it blew out and started leaking....

4. Had a Harrd/ soft seize... it was soft cause it didnt freeze up, but it came on suddenly and hard, back wheel locked up

5. When I re ground a new head gaket and installed I thought all was solved.

6. Wait, I had just installed a decomp cable, because I put the stock head back on, yet I am using Magura brake levers, and the travel for the cable is more thatn the stock set up, so it was constantly engaged and decomping the damn thing . My wife pointed down and said look oil/ smoke comming out the decomp piston area.

7.Ripped the cable off and fired right up!

8. Rode it home with no problems...runs like a champ!