Tuning/Reed Valves

Striper15

Recruit
Joined
Oct 11, 2007
Messages
5
This is my first post and sure would appreciate any help if you have it. I have a brand new 2006 Yamaha 25, 2-stroke engine with just about 20 running hours on it. It always seems difficult to cold start and never seems to hold a steady idle rpm (it fluctuates +/- 50rpm's) and sometimes stalls at idle, even when hot. It's my first ever outboard, so this may be "normal" for a 2-stroke. Is that right?? Can I adjust anything to help?

Has anyone ever tried replacing or modifying their reed valves to increase engine performance? In “Googling” around, I’m learning more about reed valves and that they can be a source of modifying over factory installed ones:

dansmc.com/reedvalve.htm
bobsmachine.com/Products/boysen_main.cfm

They say that reed valves can help with cold starts and idling. I looked at my shop manual and replacing them looks a little challenging. Don't mind doing the job, however, if they will help.

Thanks!

Eric
 
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deejaycee_2000

Captain
Joined
Mar 28, 2006
Messages
3,447
Re: Tuning/Reed Valves

Welcome to iboats :) ...... yes reeds helps with performance but stick with boyesen reed valves, they are the best .... it sound like you just need a carb clean and a bit of an air/fuel adjustment ......
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Tuning/Reed Valves

reeds aint gonna help,unless the current reed set is defective or misaligned on the reed block.
that would be warrenty.
that 25 should be running by the second pull and once warm it should idle all day if that is what you wish.
its broke, it may or may not be warrenty,depends on if its a defect in materiels or workmanship or bad fuel/gummy carb.
 

Striper15

Recruit
Joined
Oct 11, 2007
Messages
5
Re: Tuning/Reed Valves

Thanks guys! That's what I wanted to know. I have the shop manuals and will try and tune it a little by adjusting the idle screw and throttle plate.

Question: If adding aftermarket reed valves (like the Boyesen's) wouldn't help with starting/idling, what would changing the reed valves do? I would think that they play a major role in all aspects of the engines running; they are controlling the key elements, air and fuel.

Thanks again!
 
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