dauntless-n-miami
Recruit
- Joined
- Jul 2, 2013
- Messages
- 1
Hello to all, first time on this forum.
I am experiencing a moderate rough idle and low rpm stall as of late with my 2007 90 TLR 2 stroke. It appears my primer bulb was not E10 compatible as is the fuel line when I replaced them some time back. I start the motor a few time each month when I can't get out with the boat. Last month I had no issues with idle, 2 weeks ago the issue presented. I do use fuel and Ethanol treatment with every tank fill along with Yamaha Ring free.
The O/B has just 97 hrs on it, I thought it might be the spark plugs so I replaced them (correct spark gap .039"). Started the O/B idle still rough, rpm would dip down to about 450-500 and stall. I inspected the fuel/water separator and viewed very small dark particles in clear site bowl. Engine mounted fuel filter also displayed same condition. I proceeded to drain the carb bowls for further inspection. Top and middle carbs drained clean but bottom carb had similar particles and drain fitting was coated with a greenish film. I assume the film is congealed 2 strk. oil and fuel?
I carefully sprayed into the bowl areas (externally without any disassembly) with carb cleaner in hopes of dislodging possible contaminents. I also sprayed and cleaned the throat and butterfly area of the carbs. All fuel filters have been replaced along with proper primer bulb and O/B rough idle/stall condition remains the same.
It is apparent a carb rebuild is in order. I have contacted area boat service shops and the quotes vary from the mid $200's up to the $500's, "holy #%*@"!!! Are these quote accurate??? I am considering doing the rebuild myself with a good friend who just recently rebuilt his 2 stroke 90 carbs with great success. The rebuild carb kits are between $24 thru $31 on-line and a Yamaha service/repair manual is in order as well.
What has perplexed my friend and myself are the "Pilot Screws" found on my Keihin carbs!!! They are capped with what appears to be a brass plug. My friend's Yamaha 90 is of a 1999 vintage and his Keihins have exposed pilot screws for adjustment. Our carbs appear very identical with that one exception. Are my 2007 carbs not designed to have the pilot screws adjusted?
There were 2 other simple test that I did with the motor. One was to check the actual (visible) ignition spark to the plug (Snap-On tester) which was adequate. The second was to pull off the spark plug boot (1 cylinder @ a time) with motor running and observe idle. Top and middle cylinders demonstrated increased hesitation when boot was pulled but bottom cylinder presented little change.
I apologize for the lengthy post, any and all assistance with my issue will be greatly appreciated. Also suggestions of Yamaha service/repair manual suppliers would be great. :joyous:
My Keihin model number is:6H130 UL26 BCP
Yam. 90 TLR model number is: 6H 1 L 1033531 J
Date: 11/07
Thanks,
Angel M.
I am experiencing a moderate rough idle and low rpm stall as of late with my 2007 90 TLR 2 stroke. It appears my primer bulb was not E10 compatible as is the fuel line when I replaced them some time back. I start the motor a few time each month when I can't get out with the boat. Last month I had no issues with idle, 2 weeks ago the issue presented. I do use fuel and Ethanol treatment with every tank fill along with Yamaha Ring free.
The O/B has just 97 hrs on it, I thought it might be the spark plugs so I replaced them (correct spark gap .039"). Started the O/B idle still rough, rpm would dip down to about 450-500 and stall. I inspected the fuel/water separator and viewed very small dark particles in clear site bowl. Engine mounted fuel filter also displayed same condition. I proceeded to drain the carb bowls for further inspection. Top and middle carbs drained clean but bottom carb had similar particles and drain fitting was coated with a greenish film. I assume the film is congealed 2 strk. oil and fuel?
I carefully sprayed into the bowl areas (externally without any disassembly) with carb cleaner in hopes of dislodging possible contaminents. I also sprayed and cleaned the throat and butterfly area of the carbs. All fuel filters have been replaced along with proper primer bulb and O/B rough idle/stall condition remains the same.
It is apparent a carb rebuild is in order. I have contacted area boat service shops and the quotes vary from the mid $200's up to the $500's, "holy #%*@"!!! Are these quote accurate??? I am considering doing the rebuild myself with a good friend who just recently rebuilt his 2 stroke 90 carbs with great success. The rebuild carb kits are between $24 thru $31 on-line and a Yamaha service/repair manual is in order as well.
What has perplexed my friend and myself are the "Pilot Screws" found on my Keihin carbs!!! They are capped with what appears to be a brass plug. My friend's Yamaha 90 is of a 1999 vintage and his Keihins have exposed pilot screws for adjustment. Our carbs appear very identical with that one exception. Are my 2007 carbs not designed to have the pilot screws adjusted?
There were 2 other simple test that I did with the motor. One was to check the actual (visible) ignition spark to the plug (Snap-On tester) which was adequate. The second was to pull off the spark plug boot (1 cylinder @ a time) with motor running and observe idle. Top and middle cylinders demonstrated increased hesitation when boot was pulled but bottom cylinder presented little change.
I apologize for the lengthy post, any and all assistance with my issue will be greatly appreciated. Also suggestions of Yamaha service/repair manual suppliers would be great. :joyous:
My Keihin model number is:6H130 UL26 BCP
Yam. 90 TLR model number is: 6H 1 L 1033531 J
Date: 11/07
Thanks,
Angel M.