1986/7 DT150 Reed valve variance??

[boatleg]

Hi all, please excuse the long winded question.....

I have just pulled out the reed valve assembly from my 1986/7 DT150 as I have overhauled the carbs. (Sorry, not quite sure of the exact year but it is an early one....no serial number as the clamp brackets have been replaced, loosing the id plate.)
Anyway, I also have a spare inlet case/reed valve assembly (RVA) and carbs off a similar motor.
What I am not sure on is that the RVA currently in use has only one side of each of the three double exit ports with reed valve stoppers/fingers fitted. Each other paired side has a flat plate fitted in place of the fingers which I guess in effect reduces the outlet by half.(??)

Question: Why is this the case and can I then use the other spare assembly with all ports fitted with reeds and stoppers/fingers with no negative effects?

Appreciate any guidance you may have.

Thanks from Australia.

[boats.net]

Not sure what you have, reeds should have a stop on top of plates.

[boatleg]

Sorry, not sure what you mean by that.
I ended up finding a mechanic who really knows his stuff on these older engines. Turns out the 150HP had one side of the reed valve closed off and the higher HP's had both sides open. He couldn't see an issue with using the higher HP reed valve assemble so I installed. She is running great. Can't seem to notice if any slower out of the hole, as he mentioned this could be the case.
Ran up to about 3400rpm and had no hassles. Don't really need to go much harder on a 15'3'' hull. Ran at idle and in gear at idle for the first time, every time all day. This is probably related to the basic carb work I did as well.
How good is it when you can take her out and not have running issues!!!
Ok, one issue left.....I will post a new topic.

[Shaun4BigBlocks]

Hi all, please excuse the long winded question.....

I have just pulled out the reed valve assembly from my 1986/7 DT150 as I have overhauled the carbs. (Sorry, not quite sure of the exact year but it is an early one....no serial number as the clamp brackets have been replaced, loosing the id plate.)
Anyway, I also have a spare inlet case/reed valve assembly (RVA) and carbs off a similar motor.
What I am not sure on is that the RVA currently in use has only one side of each of the three double exit ports with reed valve stoppers/fingers fitted. Each other paired side has a flat plate fitted in place of the fingers which I guess in effect reduces the outlet by half.(??)

Question: Why is this the case and can I then use the other spare assembly with all ports fitted with reeds and stoppers/fingers with no negative effects?

Appreciate any guidance you may have.

Thanks from Australia.

1987-1989 carbureted DT150's, DT150SS, 175's and 200's are all pretty much the same with the exception of the reed valves and carb bore size (this is how Suzuki marketed different HP levels out of one $$ engineered foundation). All heads including 1986 interchange with all 87-89 blocks as long as you use the proper head gasket and ignition. Reeds in DT150's are governed where as the 150SS and up are all open flow.

YES you can use the open RVA's (much like upgrading to Boyesen reeds) just make sure you adjust the air to fuel mixture as it will be off just enough to slowly kill your powerhead (lean burn is WAY worse on 2 strokes then 4 strokes). Run a tad rich to be safe and just clean plugs with gasoline every so often more. Just remember that the DT150 was the most reliable of the bunch- kind of like if a dude benches 350 but only goes up to 250 he won't tear a rotary cuff kind of thing. With the lack on new/refurbished parts I would just be happy to keep it running personally.

If I get a chance I will post the specs for the whole family. I'm about to organize all my info and make one good sticky as no one seems to ever know anything about these engines. Those new 4 Strokes are AWESOME but I sure like being able to work on them without my laptop... Glad you found out how to cheat the Suzuki system (PS: keep in mind these things have a mean stroke and are WAY torquey for a 150 compared to say a high revving XR6 that has to bust a nut to make it's HP. So when you do tweak these things they REALLY hall some ass!!