1984 Gyro Bogging

tucker · Post by **tucker** » Sun May 10, 2009 6:07 pm

I've resurrected a 1984 Gyro. Bystarter seems to be working per test in Spree manual I am using for information. Seems to be bogging because I can get it running and it will eventually increase in speed. I noticed today that if I take the whole slide mechanism out of the the carb the it runs like a scalded rabbit. I can ajust the rpm by manually sliding the throttle slide up and down by hand. Acts just like you would like the carb to act if it were fully assembled. Air box is installed and I have played with the needle jet. Seems to run a little better towards the leaner end. My conclusion is that with the slide taken out I am allowing it to run on the main jet which is when it runs excellent. Plug looks good, a little grey but not rich. Just went back out and ran it again with the air box off and it seems to run poorer. I now think it has a partially clogged pilot jet if it runs fine on the main and poorly with the slide installed. Am going to pull the carb and clean, clean, clean.
However, I am looking forward to your opinions.
Thanks.

chevyguyjay · Post by **chevyguyjay** » Sun May 10, 2009 6:26 pm

well, u dont want a gray plug. my guess, carb. u check the compression? if its low, u will have a hard time tuning. been down that road.

tucker · Post by **tucker** » Mon May 11, 2009 7:59 am

chevyguyjay wrote:well, u dont want a gray plug. my guess, carb. u check the compression? if its low, u will have a hard time tuning. been down that road.

Grey may have been a poor choice of words. I know the color I need when perfect or close to perfection. I try not to get that lean until I am sure it is broken in, rings are seated, and I am not going to stick a newly rebuilt two stroke engine. My goal right now is a decent ilde, strong pull up from idle to through to where the slide pulls the needle to the top and the main jet is doing its thing. Right now just the main is where is needs to be and the needle/slide are not allowing the right amount of fuel at the right time. Thanks for the compression idea, haven't checked it with a guage but I will do that today. I feel like I have a dirty jet and the fuel flow is getting restricted at the low and medium rpms. thanks for the help.

chevyguyjay · Post by **chevyguyjay** » Mon May 11, 2009 11:10 am

yea, im working on a customers 85 gyro now. hes only got 80-85 psi. im going now to pick up a set of rings for it. he bought a aftermarket stock replacement carb for it. it took it apart just to check if the bowl had any dirt in it. the main jet dont even have any numbers on it?? once i get it going, do lots of plug chops.

Wheelman-111 · Post by **Wheelman-111** » Mon May 11, 2009 11:47 am

Greetings:

I recently read what the ideal plug color is:

"Cardboard"

mousewheels · Post by **mousewheels** » Mon May 11, 2009 4:06 pm

I feel like I have a dirty jet and the fuel flow is getting restricted at the low and medium rpms

Try unplugging the electrical connections to the bystarter before a cold start. That will leave the enrichenment on. If it runs better when warm, clean the idle jet (again??

), look for possible air leaks, and on the off chance the air filter is missing put one in.

tucker · Post by **tucker** » Thu May 14, 2009 10:31 am

Disassembled the carb again and soaked in cleaner overnight. Found a little trash in the carb bowl. Cleaned out all jets and reassembled. Checked compression and it was ok. Don't think it is the compression because once it gets up on the main jet it runs wonderful, but getting the rpms up to that point is an exercise in patience. I noticed both of the spare reed valves that came with the bike are in bad shape. Small cracking of the bakelite frame that holds the reeds. The cracking is at the point of contact at the top of the reeds, opposite from the screws. Is there a problem with these reed blocks cracking, I don't know if the extras are off the Gyro or not. I think that will be my next inspection point. Would bad reeds cause poor acceleration?
Judging from all the posts in the last week it seems carb problems are the most perplexing and frequent. Thanks to those whose skill lies in this area for their contributions.

tucker · Post by **tucker** » Mon May 18, 2009 9:05 pm

Well, I cleaned, and cleaned, and cleaned. And it did naught for the problem. I looked at all the stickys trying to take advantage of the great advice in those sections. I looked at pictures of disassembly and reassembly trying to make sure I had not missed anything. Ran great with the throttle sleeve out of the carb when it was just the main jet. Ran very poorly with the sleeve installed. I pulled the carb of the Gyro and held it in my hand to see if the throttle cable was doing its job. The slide did not retract very high into the upper recess. Got to looking the sleeve and I came to the realization that I had the slide installed upside down. You say how can that happen? Simple. It was that way when I got it and I don't have a manual so I put it back together very carefully the way I found it. No excuse. No wonder I could not set the idle. The idle screw kept hitting the side of the slide and I thought that was the dumbest design,especially from Honda. And as for the poor running,well I am amazed it ran at all. However, now there is another 1984 Gyro on the road and running like a scalded cat. Thanks for all the encouragement and advice.

Wheelman-111 · Post by **Wheelman-111** » Mon May 18, 2009 11:52 pm

Greetings:

Glad you figured it out!

Honda Spree and Elite 50 Forums

1984 Gyro Bogging

1984 Gyro Bogging

The Color of Cardboard

Thanks

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