115 yamaha 2stroke bogging down

[Eddie Ray]

1998 115 Yam 2stroke. Had some bad gas. Got that all out . changed plugs ,and had it running I thought well.
Took it bout today to give it a run. At first ran very well ,after about fifteen minutes . It started bogging down .it seems to idle well and dose good at low RPM / speed. When you go to get her on plane she bogs down.
Looked for water in the fuel,didn't find any? I did notice that the primer bulb dose not stay hard . But if you pump it it dose not seem to make much difference. Looked at the new plugs,they looked okay.
I am sure that I will need to take apart and clean the carbs? Probably rebuild them while they are out? Sound about right? Or am I missing something else too?
Thanks for any advice or help.
Eddie

 

[99yam40]

Re: 115 yamaha 2stroke bogging down

all the lines, pump, and carbs have stuff in them from the bad gas and need to be flushed and cleaned would be my guess

 

[Natty Light]

Re: 115 yamaha 2stroke bogging down

I had a similar problem at the beggining of the summer. I kept finding black specs in my fuel filter and my engine would bog down at 3/4 to full throttle. I continued to dump the debris from the filter until it stopped showing up. I also ran Yamalube Ring Free Plus at a rate of 1 ounce for every 2 gallons of gas in my next full tank of gas. After that I backed off to the normal ring free dosage and changed my fuel filter. That worked for me. I have no idea if that is proper procedure, but it made sense to me and my engine has been running great since then.

 

[Bamaman1]

Re: 115 yamaha 2stroke bogging down

The 90/10 gasoline is giving marine mechanics a lot of work. The trick is to keep fresh gas in your boat, and treat any gasoline that's not going to be used in 2 weeks. It's really unhealthy on your fuel pump which has a rubber membrane.

The carburetors on your boat virtually never need rebuilding. If you're careful in disassembly, you can clean them and only be out $3 for a can of carburetor cleaner. I'm not a mechanic, but I can remove, clean, reassembly and re-install a pair of 115 hp carbs. in just over an hour. I do have a shop manual for a backup info, however.

I would suggest cleaning the carbs, install a new fuel pump membrane, install a new fuel filter (under the carbs.) and check the end of the fuel siphon tube in your gas tank to see if there are any stoppages.

 

[Eddie Ray]

Re: 115 yamaha 2stroke bogging down

Thanks for all the help.
One more question ? Should the primer bulb stay firm ,or is okay for it to get soft as long as it dose not collapse ?
I seem to have a fuel flow issue? I know,probably junk in the lines. But the gas looks pretty clean?
Should the water separator/filter on the engine stay filled to the top? Mind drops to about midway when I run idle it?
I know, that was more than one question. My bad.
Eddie