I have a 1967 Honda ct90 trail bike, great little bikes for putting around. Anyway, I can't get the damn thing to run, it has spark, battery is good, I pulled the air box (so it should have plenty of air), and checked the timing (looks good), I've also cleaned the Carb. about three times, so there shouldn't be a blockage. It will start if I spray starter fluid down its throat but will burn off the fluid and die. Fuel lines ain't plugged either.

What do you think? Suggestions???


Thanks,
John:confused:

how old is the fuel?

and have you taken a compresion test?

also i know you said that you cleaned the carb but sometimes on an older bike i will check and make sure that gas is flowing into the carb.

i'm not familiar with a ct90 but if it is a four cycle maybe inspect the valve train. (ie. cam, rockers, and chain)

Thanks will do:D

Sweet Bike.

Anyways, it sounds like fuel problem (obviously). Check the carb again. The float needle could be stuck (are you getting fuel into the bowl of the carb?), make sure you remove the Main jet, pilot jet, and rich/lean screws and clean all the crap out when you are doing a carb clean. Often times people say they clean the carb and when in reality they just dunk the carb in a coffee can full of gas. Hell, I would even go buy a rebuild kit for it (they should be available). It should include the jets and a new needle and seat - thats easier then cleaning.

Seeing as it runs on Starter fluid, then I would assume the ignition and valvetrain are in good working condition. It usually takes an act of God to wreck an old Honda, so I am sure it is something simple.

It was also a good suggestion to change the gas, it probably also wouldnt hurt to put in a new plug (It may be able to flame on ether, but gas might be enough to foul the plug??)

Sweet, I'll check out the Carb in more detail.

Thanks

John

i am a certified bike tech . i would check the fuel petcock after u drain the old fuel some of the older bikes had a vacum operated pet cock .i would check the vacum line if you have one as well as the screen on the pet cock and on the vacum operated ones you will have a check ball that gets stuck after sitting a while .

I have a 68 CT90 that I am fixing up and after I cleaned the gas tank I discovered that these have a standpipe in the tank and there are three positions on the carburetor fuel supply valve. Off, Normal and Reserve AND if you position it in between you get "nada". In my case I did not have the tank filled up over the stand pipe, so it would only run in "reserve". Take the fuel hose off and operate the valve, gas will run all over your floor or not at all.

The pilot(slow speed) jet is plugged.

Definately a fuel related prob. Besure the bowl of the carb is getting fuel using drain screw. If no fuel find out why. If bowl is filling then it might be a plugged pilot. Be sure you are using fresh fuel and not something that was out in the shed for the lawnmower. Todays fuel has a short shelf life.