From high comp to lower comp

Peteyparado · Post by **Peteyparado** » Wed May 18, 2016 6:08 am

Got a friends scoot compression is at 155psi runs great no issues..he just raised the cylinder a bit to lower the compression now it's at 130psi, but the scoot runs real rich now! gargles just pass 1/4 throttle to about power band but still rich it has that blaaaa noise try Giving more throttle just more blaaa blaaa to hit hit power band then it wants to rev Barley tho.. It's like giving throttle an your holding the brakes.. The revs hold at a rpm trying to get power.. Can lowering the comp affect the jet size that much ? I'm going change jet in the morning since its late now..

patthesoundguy · Post by **patthesoundguy** » Wed May 18, 2016 9:10 pm

Raising the the cylinder changes the timing. When you raise the exhaust port I have been told it can make run a little richer. I think the best idea would be to raise the head and drop the cylinder back down to return the timing to its former glory. See if that cures the issue.

Peteyparado · Post by **Peteyparado** » Wed May 18, 2016 10:47 pm

Yeah the main was at 138 I had to bring down to 130 an needle at its leanest to get it running

Wheelman-111 · Post by **Wheelman-111** » Thu May 19, 2016 9:10 am

Greetings:

Quoth PeteyParado:

Got a friends scoot compression is at 155psi runs great no issues..he just raised the cylinder a bit to lower the compression now it's at 130psi, but the scoot runs real rich now!

It is not demonstrated that the scooter is running rich. All we know for sure is that it is running Badly. PTSG is correct in surmising that the port timing is probably the issue. Sometimes there's some benefit from swapping to a different jet, but jetting probably won't be the cure.

Peteyparado · Post by **Peteyparado** » Thu May 19, 2016 7:54 pm

Ok so I pulled out one of the base gaskets ran the scoots put back the 138mj an richen the needle an bingo Back in action an the comp is down to 150psi..

Wheelman-111 · Post by **Wheelman-111** » Thu May 19, 2016 8:55 pm

Greetings:

How many base gaskets were added to go from 170PSI to 130?

Peteyparado · Post by **Peteyparado** » Thu May 19, 2016 11:43 pm

It was .5 mm gasket comp at 165psi added custom 1.3mm gasket to bring down to 130psi..

patthesoundguy · Post by **patthesoundguy** » Sun May 22, 2016 2:59 pm

1.3mm is totally enough to really bugger the timing.

Peteyparado · Post by **Peteyparado** » Sun May 22, 2016 5:54 pm

Yeah it was an extra gasket from my full drag racing bore..but yeah got her going..

Honda Spree and Elite 50 Forums

From high comp to lower comp

From high comp to lower comp

Re: From high comp to lower comp

Re: From high comp to lower comp

Re: From high comp to lower comp

Re: From high comp to lower comp

Re: From high comp to lower comp

Re: From high comp to lower comp

Re: From high comp to lower comp

Re: From high comp to lower comp