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LOW COMPRESSION ON FRANKENSPREE

Posted: Tue Aug 14, 2012 4:40 pm
by jmcginn68
hi,i purchased an 85 spree basket case,guy said it siezed+he broke new ring assembling it.it came w new DOMED PISTON+HEAD (old ones were flat)i measured cylinder its within specs,honed it but ring would not colapse enogh w expansion ring under it.(i notice aftermarket pistons dont have the third octagon ring)so i omitted expansion ring.the lettering was correct the ex on piston is pointing to exhaust,the lawn mower guy said"thats a tight fit you will have high compression"im getting a whopping 30 lbs. + it wont stay running.i put new head+ base gaskets+sprayed soapy water+no bubbles.IM STUMPED.is the crank,stroke,or connecting rod different on early + later sprees.i want to put new reed valves but dealer said discontinued.does anyone know a repudable place to get them?last resort crank seals,i dont want to go there.thanx for any feedback.

Re: LOW COMPRESSION ON FRANKENSPREE

Posted: Tue Aug 14, 2012 6:21 pm
by Bear45-70
Actually the original '85 Spree had a dished piston, not a flat piston. The domed piston is the factory replacement and running the original '85 head with the domed piston is a performance enhancer, more compression. And the rest of the engine is the same, late and early. Have you confirmed on a running engine that the compression gauge is good?

Re: LOW COMPRESSION ON FRANKENSPREE

Posted: Tue Aug 14, 2012 6:43 pm
by jmcginn68
THANK YOU so much for your thoughts bear.the original pisto n is "dished" sorry for calling it flat.im leery of running flat head w dome piston due to piston hitting head.would every thing else withstand more compression having 25 yrs+2000k?have not confirmed tester is good but when i gave it the "cuban thumbprint plug hole test"it showed little force on my thumb.i have to eyedrop gas in plug hole to start+it wont run long,not enough power to pull my pot belly.thanx for any more ideas !!!

Re: LOW COMPRESSION ON FRANKENSPREE

Posted: Tue Aug 14, 2012 7:38 pm
by Bear45-70
It will work just fine and no the piston will not hit the head.

If the engine starts with primer in the plug hole, your compression is not

30 PSI because these engines will not fire at less than 70 PSI.

Clean the carb per instructions in Wikispreedia.

Re: LOW COMPRESSION ON FRANKENSPREE

Posted: Wed Aug 15, 2012 2:05 am
by jmcginn68
carb was cleaned thoroughly

Re: LOW COMPRESSION ON FRANKENSPREE

Posted: Wed Aug 15, 2012 2:22 am
by Bear45-70
Once is not enough with these carb. The average noobee takes 3 tries before getting it right. Clean the carb per the instructions in Wikispreedia.

Re: LOW COMPRESSION ON FRANKENSPREE

Posted: Wed Aug 15, 2012 2:33 am
by jmcginn68
soaked it all in acetone for 2 weeks,pushed out the "main jet? thing w the little holes blew air + carb clean every wich way ,even that hole in bowl bottom.

Re: LOW COMPRESSION ON FRANKENSPREE

Posted: Wed Aug 15, 2012 2:34 am
by jmcginn68
i also put all new seals+float needle

Re: LOW COMPRESSION ON FRANKENSPREE

Posted: Wed Aug 15, 2012 10:25 am
by noiseguy
Bear45-70 wrote:Once is not enough with these carb. The average noobee takes 3 tries before getting it right. Clean the carb per the instructions in Wikispreedia.
Heck, I've got a carb on my SA50 that I've had apart 6 times and it's still not right ;)

Re: LOW COMPRESSION ON FRANKENSPREE

Posted: Wed Aug 15, 2012 10:27 am
by noiseguy
jmcginn68 wrote:soaked it all in acetone for 2 weeks,pushed out the "main jet? thing w the little holes blew air + carb clean every wich way ,even that hole in bowl bottom.
I don't hear mention specifically of the idle jet... it won't idle with this plugged... and it's always plugged.

Re: LOW COMPRESSION ON FRANKENSPREE

Posted: Wed Aug 15, 2012 12:48 pm
by Bear45-70
jmcginn68 wrote:soaked it all in acetone for 2 weeks,pushed out the "main jet? thing w the little holes blew air + carb clean every wich way ,even that hole in bowl bottom.
Acetone is NOT carb cleaner and is nowhere near caustic enough to clean a carb, especially one with very little plugged passages, AKA the idle or pilot circuit.

Re: LOW COMPRESSION ON FRANKENSPREE

Posted: Wed Aug 15, 2012 1:37 pm
by abreen89
jmcginn68 wrote:soaked it all in acetone for 2 weeks,pushed out the "main jet? thing w the little holes blew air + carb clean every wich way ,even that hole in bowl bottom.
You need this http://www.oreillyauto.com/site/c/detai ... &ppt=C0126

Re: LOW COMPRESSION ON FRANKENSPREE

Posted: Wed Aug 15, 2012 10:50 pm
by martynkim
abreen89 wrote:
jmcginn68 wrote:soaked it all in acetone for 2 weeks,pushed out the "main jet? thing w the little holes blew air + carb clean every wich way ,even that hole in bowl bottom.
You need this http://www.oreillyauto.com/site/c/detai ... &ppt=C0126
Not needed. $ on something that works but, an added cost. $2 can of carb cleaner will do. Just follow the instructions.

Re: LOW COMPRESSION ON FRANKENSPREE

Posted: Wed Aug 15, 2012 11:01 pm
by Bear45-70
martynkim wrote:
abreen89 wrote:
jmcginn68 wrote:soaked it all in acetone for 2 weeks,pushed out the "main jet? thing w the little holes blew air + carb clean every wich way ,even that hole in bowl bottom.
You need this http://www.oreillyauto.com/site/c/detai ... &ppt=C0126
Not needed. $ on something that works but, an added cost. $2 can of carb cleaner will do. Just follow the instructions.
Over the years I have had poor performance from the spray carb cleaners and years of crap in the carb. The dip has always worked in the end.

LOW COMPRESSION ON FRANKENSPREE

Posted: Wed Aug 15, 2012 11:25 pm
by abreen89
Is carb clean cheaper in Tacoma in graham I pay 4+ a can