88 Suzuki DT55

[sifty]

88 Suzuki DT55

Motor was running great I was on plane and adjusted trim motor lost rpms when I slowed down to check onit it would never get back on plane. No low oil lights or buzzers hit reset on motor anyway. Starts right away and idles great rebuilt carbs two months ago. Did compression check 120 psi in all three cylinders. Engine will rev in neutral but 3300 under load is it. Fresh fuel with stabil. I'm stumped. Any help would be appreciated.

 

[deejaycee_2000]

Re: 88 Suzuki DT55

Re: 88 Suzuki DT55

When last did you replace the impellar?

 

[sifty]

Re: 88 Suzuki DT55

Re: 88 Suzuki DT55

It was last year the pressure out of hole looks good. Would something in lower end binding cause this problem?

 

[sifty]

Re: 88 Suzuki DT55

Re: 88 Suzuki DT55

Thanks for reply deejaycee. Took boat out again tried reset of oil sensors nothing changed. boat rpms are at 3000 rpm not 3300 as I stated earlier. I have no buzzer and no lights coming on. But it acts like it in limp mode. Any ideas?

 

[sifty]

Re: 88 Suzuki DT55

Re: 88 Suzuki DT55

shot in the dark here but if motor won't reset would un-hooking batterys cause reset? Like if you get check engine lite in your auto and unhook batterys it will remove lite until symptom happens again.

 

[deejaycee_2000]

Re: 88 Suzuki DT55

Re: 88 Suzuki DT55

If there is a real problem, unhooking the battery won't reset anything .... normally when the engine cut the cylendars to stay below 3000rpm it is either an oil or waterflow problem .... by odd occasion the waterflow or your oil flow switch goes bad and can cause this, but ... is the water stream strong you would say?

 

[sifty]

Re: 88 Suzuki DT55

Re: 88 Suzuki DT55

water flow is strong. I'm leaning more to the oil sensor. Just weird that no lights or buzzer. I think I will take it to local boat mech. and let someone with alittle more experiance have a shot at it. I will reply back with answers if he finds one. Thanks deejaycee.

 

[bossee]

Re: 88 Suzuki DT55

Re: 88 Suzuki DT55

Hi,
Low Oil level, low oli flow, low voltage (and over rev) are things that can reduce RPM on a Suzuki to 3000 RPM. Overheat will reduce RPM to 2000.

/Bo

 

[lunchman3815]

Re: 88 Suzuki DT55

Re: 88 Suzuki DT55

Not that I can help you, but my 1989 DT65 is doing the same exact thing. With the muffs on it will rev fine, once under load right to 3000 and thats it. I'll keep an eye on this post. Hopefully we can figure this out. The only thing I can come up with is that the oil reset switch/module is bad.
Russell

 

[deejaycee_2000]

Re: 88 Suzuki DT55

Re: 88 Suzuki DT55

Not that I can help you, but my 1989 DT65 is doing the same exact thing. With the muffs on it will rev fine, once under load right to 3000 and thats it. I'll keep an eye on this post. Hopefully we can figure this out. The only thing I can come up with is that the oil reset switch/module is bad.
Russell

Have you replaced your fuel pump diaphram? It seems that all 65hp suzuki's have a problem with this one time or another ....

 

[lunchman3815]

Re: 88 Suzuki DT55

Re: 88 Suzuki DT55

Just ordered the kit to replace rebuild the fuel pump. Hope it works. Thanks

 

[gabollini]

Re: 88 Suzuki DT55

Re: 88 Suzuki DT55

Not that I can help you, but my 1989 DT65 is doing the same exact thing. With the muffs on it will rev fine, once under load right to 3000 and thats it. I'll keep an eye on this post. Hopefully we can figure this out. The only thing I can come up with is that the oil reset switch/module is bad.
Russell

Have you replaced your fuel pump diaphram? It seems that all 65hp suzuki's have a problem with this one time or another ....

 

[gabollini]

Re: 88 Suzuki DT55

Re: 88 Suzuki DT55

Not that I can help you, but my 1989 DT65 is doing the same exact thing. With the muffs on it will rev fine, once under load right to 3000 and thats it. I'll keep an eye on this post. Hopefully we can figure this out. The only thing I can come up with is that the oil reset switch/module is bad.
Russell

Have you replaced your fuel pump diaphram? It seems that all 65hp suzuki's have a problem with this one time or another ....

I have a dt 65 1988 and the fuel pump assembly (the plastic piece on which the diaphram is placed) is leaking gasoline because it is cracked. That is, the thing isn't sealed. In fact, I discovered that it was leaking fuel because the housing was cracked. Mine was cuting out at about 4K. Just had carbs cleaned, and may have been water or varnish in an old fuel tank. Maybe you should check this as well.

 

[sifty]

Re: 88 Suzuki DT55

Re: 88 Suzuki DT55

Well just got call from dealer. They are telling me that oil pump stopped working. Recommend that I buy new motor 6000 bucks. Compression check was 120 on each cylinder before I took it in. He is worried that oil was not reaching the crank and if I throw a new oil pump on motor could grenade next time out. They obviuosly give me nothing on trade. What is your guys thoughts?

 

[deejaycee_2000]

Re: 88 Suzuki DT55

Re: 88 Suzuki DT55

They just wanto sell you a new motor, you can always just disconnect the oil pump and run it on premix, it is easy to do ....

 

[sifty]

Re: 88 Suzuki DT55

Re: 88 Suzuki DT55

Deejaycee, I think I will go with your idea. Thanks for all your help I will keep you updated.