1997 challenger 1800 port engine bogs to 4k in turns to left

[mustang1910]

the problem I'm having is in turns to the left the port engine bogs to 4k. it will immediately return to the previous rpm(about 7k) after i straighten out. Here is some things i have done recently removed coffmans exhaust, removed aftermarket flame arrestors, rebuilt/rejetted to oem specs on carbs, installed oem air boxes, installed oem exhaust, new water regulators, all new fuel lines and filters. the other problem this same engine has is when i go to full throttle it hangs at 4-4.5k until i cycle the throttle from wot to idle and back to wot. tried rebuiding and cleaning the raves and also tried adjusting the red caps but this made no change toward the better. also set popoff pressure to spec. i know im missing something simple. thanks in advance.

 

[Dr Honda]

Check the compression on that engine. I think you will find it low.


Most boats/skis will drop some RPM's to the left... but it shouldn't be that far.

 

[mustang1910]

sorry forgot to put that in. both cylinders are at 145 psi.

 

[Guest_User]

unlike yamaha jet boats that use different pitch impellers for Port and Starboard engines, SeaDoo uses the same pitch on both. I experience the same rpm drop but not as low as your`s. it does recover as soon as the steering course is corrected to straight. Ours doesnt necessarily bog, it just drops down a bit at the same throttle. If I am in a long sweeping turn, I just push that throttle stick forward a bit...

but as the good Doc suggests, check the compression and go from there... I would also take a peek at the condition of the impeller and wear ring while your checking things out...

 

[Dr Honda]

unlike yamaha jet boats that use different pitch impellers for Port and Starboard engines, SeaDoo uses the same pitch on both. ....

Actually... on many of them... they use different pitches. But, the aftermarket Co's just list a single.



OK... so, 145. That's ok. Hummmmmmm...................................




thinking.

 

[Guest_User]

Actually... on many of them... they use different pitches. But, the aftermarket Co's just list a single.



OK... so, 145. That's ok. Hummmmmmm...................................




thinking.

ummm, ya lost me Doc! which boats, seadoo or yami uses different pitches?
I was unaware of seadoo 2 stroke boats having different pitches... DOH!

I think both my impellers were 027`s (oem numbers)

good thing your here Tony!:cheers:

 

[mustang1910]

last year i did both oem wear rings and sbt impellars. the starboard engine doesnt change at all when i turn right.

 

[Dr Honda]

Well....


You shouldn't fall off that far. So, I'm thinking it's a combo of things.


1) run your RAVES in full tight. (that hlps with torque)

2) make sure your water regulator isn't plugged. Or, that the orifice at the pipe isn't plugged. (a dry pipe is good for RPM, but bad for torque) Also, double check the setting.

3) You have one port of your pilot system plugged. (in the carbs) I would also consider going one step larger on the pilot jet on that engine.


Basically... if you are a little lean... and the pipe is dry, and the RAVE's are open.... you won't build torque. And... until you reset that situation (with working the throttle) you wont' build torque to rev-up again.

 

[mustang1910]

thanks, i'll try that and report back.

 

[Dr Honda]

Actually...

Do # 1 and 2. But on the carbs... open the high needles 1/8 to 1/3 turn. A little more fuel up top may help. (do not adjust the low needle. That's only for trimming idle fuel)

 

[mustang1910]

i just put brand new water regulators in. what is the correct way of checking the adjustment? i keep finding brp saying they are adjusted from the factory do not adjust. and i ordered #70 pilot jets up from #67.5.

 

[Dr Honda]

The correct adjustment is, 3 turns out from tight.

 

[mustang1910]

just wanted to update this thread. the water regulators were 2 1/2 turns out. i corrected them to 3 turns out. set the carbs and raves exactly as Dr. Honda said. the boat ran perfect. no longer bogs and revs straight to just under 7k when accelerating. thanks Dr. Honda. We had the best weekend on the boat we have ever had. :cheers:

 

[chucked]

Thanks for following up, it helps people with similar problems in the future.