Honda GYRO owners need help for drivabilty issue with my 85

[1985GYRO]

quick rundown-nov 2010 bought 85 gyro for my father for christmas- currently 7307 miles- couldnt get bike to run right- had local shop clean carb, flush tank,replace intake gasket. I got a new battery & replaced fuel lines & inline filter-runs excellent(little cold blooded for 30 sec). all stock-oil pump still in use. Drove bike a few blocks -no problems- he drove it 5 miles straight-died and would not restart-hr later started like nothing happened- issue getting worse- now 2 miles before dieing and takes a day to get it to restart.
12/31-tired of hearing him b****- drove to his house- pulled plug-good spark, did a basic finger compression test- seems ok- installed new nkg plug standard range- fired right up-let it warm up 12 sec- off i go- 2 blocks street driving- hit main road- ran it wide open running 28 mph and strong and even- 2 miles later started to surge like when u run out of fuel-feathered throttle- cleared for 1/8 block- then feels like it is at a loss for fuel again- finally pulled to side- it died and no restart- new plug slightly wet with a brown tint to it- rechecked spark-good-finger compresson same. bike is back at my house- 8 hrs later still just cranks with an ocassional sputter . last week tried to keep fuel cap loose - same issue- left cap fully off -same running problems. can guarantee it will fire right up tomorrow morning like normal

talked to a couple shops -1st thing out of their mouths is it needs a top end rebuild-without even seeing bike-one gave this anser and didnt know what a gyro was. Im not an engine expert but pulled exhaust- piston looked super clean. Fuel filter has fuel in it- even tried to flood it no gas smell when cranking or cranking with throttle wide open , or fuel/oil leaks. only issue i see is the oil line is slightly leaking on motor and i need to find a smaller line.
fuel lines are not pinched and not blocked.
please help i am lost & dont understand y it runs great for a couple miles then just feels like its fuel starved. this is not a 1x issue- it will do this every day if driven more then 2 miles.

please help

[chevyguyjay]

i worked on a black one with the same exact issues. i could never find out why why it did that? lol wonder if thats the gyro i worked on. do a true compression check with a gauge. hope u get some answers cause im curious to what answers u will get.

[odinxxix]

is it5 possible that once a gasket gets hot it expands so much that it creates a leak?

[1985GYRO]

sat all night- tried starting and it fires up but immedatly stalls like it has no fuel-exactly as my father has been saying-i unhooked fuel line between carb & my inline filter- i blew threw line with my mouth and cant do it- am i supposed to blow threw it easy like a straw or ?
im starting to think its in the carb . thinking it sits long enough and gets fuel in the carb to start and run short time- instead of flowing like it should its like an iv bottle and not getting all it is suppoed to get just a slight drip till it runs dry . sits again for a day or 2 and it has enought fuel sneaking in to get running for a short run. I cleaned carb last month but ran into issues -took it to a local shop that went nuts also till they finally got it cleaned & set up - carb was clean when i got bike originally -it was the float needle area are that they ran into dirt they said. and was told the air mixture was tempermental during set up
update: took carb apart-all is clean- stock 75 jet-gas was sitting in bowl so it appears to be getting gas- my carb appears to be working as it should

[chevyguyjay]

remove the petcock and clean it. mine was bad.

[1985GYRO]

petcock was allready gone threw and was clean -no issues with fuel flow from tank -filter.

question- i was just going over carb- the float needle(with the rubber tip) does that just sit very loose in plastic float or is it suppose to sort of lock in place? mine sits very loose and u must be steady when reinstalling . maybe the float needle is falling out of float and just sitting in the hole not moving but i doubt it has any place to get free once float screwed down . just a thought-trying to find anything to lead me to the issue------

[evilone]

Float needle is supposed to be loose like that. It does not clip in.

[Bear45-70]

The obvious thing to check here is the vent in the gas cap. To run that far before quitting is more in line with a bad vent than anything else suggested so far. Loose the cap and run it if it doesn't die in 5 or 6 miles you need to clear the vents or get a new cap.

[1985GYRO]

nope on the gas cap- allready tried to keep it loose and then tried it completely off=-basically makes it the same distance recently then it acts up .

question- picked up a cheap compression guage today- was told it should be 100 psi min --- if this guage is right- its reading 65 when bike cold and cranking 5 sec with throttle fully open-cant test warm if no start- tried a bit of oil in the hole guage reads 73- MEANING BAD CYL OR RINGS FROM WHAT I READ. - holds steady both ways. will a bike even run and good at that for a bit with compression that low?

hoping this guage is off & not thaT its really reading right.

DID I JUST SOLVE MY RUNNING PROBLEMS AND IT NEEDS A TOP END REBUILD?

[evilone]

DID I JUST SOLVE MY RUNNING PROBLEMS AND IT NEEDS A TOP END REBUILD?

If so don't cry, it's an easy fix.

[1985GYRO]

1st off will that low of compression cause the issue of running 5 miles, sputtering & no restart for a while then get progressivly worse till when it dies it takes days of sitting for it to restart? if it sounds like a sure thing i dont mind learning how to do a top end build otherwise ill just put bike back together and decide what i want to do- i have very close to what bikes worth in it allready.

Well i can use tools but have 0 experience with internal engine repairs or builds. Got nothing to lose so i looked in the shop manual- no real help for the unknowledgeable. Pulled head off, cyl off - i see the piston is very clean, the piston top does have hard carbon buildup. The 2 rings are very loose and i can remove both with my finger nails easily(thought they would be pretty tight and not easy to spin around). cyl looks clean inside and i feel no gouges or see burrs . turned fan blade on left side and piston seems to go in-out easily. kind of surprised the gaskets looked pretty good. besides ordering new gaskets, should i order 2 rings, clean piston head(how do u clean without gouging it) or just replace piston( its not cheap) and does the cyl need to be sent out to be machined(if so it will need to be sent out since i have no hone tools or feeler guages)? just found out if needed piston & cyl gasket no longer available-but rings & head gskt available

ied love to have it go from 28 top speed into the mid 30s but reading not alot to do besause of the trans set up ?
just want this thing to be safe and not have my father pushing it 2 miles when it wont refire.

[Bear45-70]

First off, you are lucky it starts at all at 65 PSI cold. I have one on my bench that has 90 PSI and it starts every time. But I also have another on my bench that will not start at all at 60 PSI.

I however agree that it is unlikely that the compression is causing you run and die issue, but trying to find any problem with an engine in a unhealthy a condition as yours is at poor path to follow at best and fool hardy at the worse.

[eliteguy50]

Your dealer should be able to hone the cylinder for you. They can also spec it to see where you are at size wise for ordering rings.

[1985GYRO]

Ok this is where i get lost. you mentioned getting correct sized rings? if cyl walls look clean and feel smooth- honing is to remove any flaws that u dont see with a naked eye and make sides smooth as polished glass for the piston to move smooth and rings to act like wipers but for oil- as piston moves- rings expand so their no oil seapage to the plug . correct? honing would possible make the diamater a hair larger? . problem is all i am seeing from bike bandit, babbits etc is stock sized ring sets- no mention of what size they are or offering of ring size options. my dealer is useless -tried telling me honda never made a bike called a gyro then said that dont order parts or service bikes more the 10 years old . everyone hates this dealer

[Bear45-70]

Ok this is where i get lost. you mentioned getting correct sized rings? if cyl walls look clean and feel smooth- honing is to remove any flaws that u dont see with a naked eye and make sides smooth as polished glass for the piston to move smooth and rings to act like wipers but for oil- as piston moves- rings expand so their no oil seapage to the plug . correct? honing would possible make the diamater a hair larger? . problem is all i am seeing from bike bandit, babbits etc is stock sized ring sets- no mention of what size they are or offering of ring size options. my dealer is useless -tried telling me honda never made a bike called a gyro then said that dont order parts or service bikes more the 10 years old . everyone hates this dealer

No, the cross hatching left by a proper hone job is so that oil will be retained on the cylinder walls so that the rings and cylinder wall wear together and seal properly. Most any machine shop can measure your cylinder to check whether in needs boring or just honing can also hone your cylinder. But if the bore is worn enough to need boring you will need a new piston and rings. Oh and you can't tell how bad a cylinder is by looking at it or feeling it. It has to be measured. If the seal between the cylinder wall and rings was bad enough to drop compression enough to need a rebuilt then there is a lot of wear somewhere. Rarely will a hone job and new rings do the job properly. Noobies and amateurs believe that is all that it takes, but pros know better, a long lasting rebuild is either done right or it will need doing again, soon. Oh and there is always going to be oil that gets to the spark plug, that's why the smart money puts a new plug in every spring. It is just cheap insurance.