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Matthew John
Matthew John, Marine Mechanic
Category: Boat
Satisfied Customers: 30
Experience:  Marine Technician, Certified in MERCRUISER AND MERCURY OUTBOARDS (Current), EVINRUDE, SUZUKI, YAMAHA, HONDA.
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I have Tohatsu 6 hp 4 stroke. Doesn't seem to rev very high.

Customer Question

I have Tohatsu 6 hp 4 stroke. Doesn't seem to rev very high. Do I need to adjust high speed jet on carb?
JA: Sometimes things that you think will be really complicated end up being easy to fix. The Marine Mechanic I'm going to connect you with knows all the tricks and shortcuts. Tell me a bit more about what's going on so the Marine Mechanic can help you best.
Customer: thanks,
JA: Is there anything else important you think the Marine Mechanic should know?
Customer: hoe do you adjust carb?
Submitted: 1 month ago.
Category: Boat
Expert:  Matthew John replied 1 month ago.

Hi my name is***** to Just Answer ! I will be assisting you.

Customer: replied 1 month ago.
I'm waiting to hear from you
Customer: replied 1 month ago.
Engine does not rev very high.
Expert:  Matthew John replied 1 month ago.

Hey ya, just a few questions to get started...

Are you operating the engine in any special conditions? e.g. Cold, freezing, or high altitude?

Are you able to visually see if the throttle valve at the throttle body/ carb opens to the full position? (Horizontal).

Can you see if the engine runs better on the remote tank (If Optional) if not, see if it runs better on a FULL tank.

Lastly... You can adjust the IDLE mixture but there is no adjustment for high speed. Make sure engine is not running hot or too cool. Check oil level and there is no RED warning light. MOSTLY for your symptoms tho is to try another fuel supply.

Regards,

Matt

Customer: replied 1 month ago.
It's new gas and a remote tank.
Customer: replied 1 month ago.
Not high altitude or cold
Expert:  Matthew John replied 1 month ago.

There is an idle mixture screw behind an Aluminium Welsh Plug that you can delicately remove to access, but your problem is higher RPM, so I will be thinking of a couple of of other things first

Customer: replied 1 month ago.
Idling is fine,what rare you thinking
?
Expert:  Matthew John replied 1 month ago.

Hey mate , sorry for the delay!!! If you have ANY suspicion of contamination of fuel, I would go straight to the carburettor, inspect/ replace In-Line Fuel Filter. When Checking the Carb I would put Fine copper electrical wire strand through all the Jet's orfices to clear. AND make sure if you have already gone through all of this already that you, make sure when you put the Carburettor low bowl back on that the BLACK PLUG is in and touching the bottom of the bowl. If you need me to send pics, just send me engine serial number! Thanks!

Regards,

Matt

Customer: replied 1 month ago.
Matt, please send photos. Model# ***** 6BS Serial 029737XG
Thanks,
Cap