jet storm 1994

[rockhound]

I have acquired this jet boat, overall not bad shape ive worked on a lot of johnson of this era . My problem is how to identfy ive looked even with mirrors and a light cant find model number anywhere. the boat was a tow away by a towing company so i have paper work from them,just neef to ID motor I bought a service manual for it havent got it yet any help appreciated

thanks steve

 

[Brad_Ct]

Most likely a Mercury Sport Jet 90 or 120, they were used in a bunch of jet boats from that era.

 

[rockhound]

I just wish I could find a model # has to be located somewhere on the engine its a 3 cylinder so 90 hp? the motor has great compression also want to find out how to run water through it when i fire it ?
thanks steve

 

[Cobra Jet Steering LLC]

it will be a force 90 hp those were made from outboard power heads placed on a jet pump see if you have any spark that was the main problem with that setup bad rectifiers blew out the brains when you shut off the engine .

 

[rockhound]

I tested the motor for spark surprised me it does,cleaned out the fuel tank it was clean.
Before i try to start it Im going make adapter for water cooling,and make sure the oil pump is working!
thanks for info steve

 

[Cobra Jet Steering LLC]

Clean the carbs very well and replace the fuel lines to them as they deteriorate and clog the needle and seat so before you put the bowls back on pump fuel to them and be sure it is exiting the needle and seat in each one also do a compression check if you did not do that yet. and read my posts about the rectifier that was the kiss of death on those engines even the outboard engines replace it with a jet ski voltage regulator 3 yellow 1 red and 1 ground will save your battery and your brain from failing This may sound odd but for many years NAPA auto parts carried a lot of parts and brains coils etc they had them in their small engine book and most of the employees had no idea, not sure if they still do today. I would go to pre mix and use a 12 volt 3 to 4 lb electric fuel pump get rid of the original one all you do is turn on the key let the pump prime the system and hit start and you will eliminate the fluctuation of rpm's caused by a pulsating weak fuel pumps. The engine will hold a steady tone and r p m at all speed. You can actually hook it up past the original pump so if you ever have an issue with the electric pump the engine will continue to run I did that on all my 2 stroke engines p w c's and outboard engines loved it. very inexpensive also, about 10 to 12
dollars.
sea doo voltage rectifier and regulator about 20 dollars.

https://www.amazon.com/gp/slredirect/picassoRedirect.html/ref=sspa_dk_detail_3?ie=UTF8&adId=A10160241PFBG82WHP6MD&qualifier=1665240824&id=4619220445713153&widgetName=sp_detail_thematic&url=%2Fdp%2FB07M9TYPGH%2Fref%3Dsspa_dk_detail_3%3Fpsc%3D1%26pd_rd_i%3DB07M9TYPGH%26pd_rd_w%3DBMR2t%26content-id%3Damzn1.sym.6bebfb2e-cf2f-489b-a5e7-bc33a85827bf%26pf_rd_p%3D6bebfb2e-cf2f-489b-a5e7-bc33a85827bf%26pf_rd_r%3DTSQY9X7KJNVZZT8B111S%26pd_rd_wg%3D7JZm0%26pd_rd_r%3Da558c922-5f5a-491b-b0e6-18d3d02e3c4a%26s%3Dautomotive%26sp_csd%3Dd2lkZ2V0TmFtZT1zcF9kZXRhaWxfdGhlbWF0aWM

 

[rockhound]

wow you are the man thank you steve

 

[Cobra Jet Steering LLC]

also be sure the fuel tank is very clean even remove it and clean it that in itself can be a serious issue causing you to wonder what is wrong you are entirely welcome Herman

 

[rockhound]

thanks again buddy appreciated

 

[rockhound]

I checked th compression 1 2 3 105 psi cleaned the tank new fuel,made adapter for water. Fired it up runs great, i've never had a jet boat so forgive me for this question do they have a reverse ?
thanks! for the help.
steve

 

[Cobra Jet Steering LLC]

HAAAAA once you TRY to drive it and if you feel like throwing up just let me know I have steering for that. I had a similar one with that engine and pump and it was what got me into designing steering for jet boats 21 years ago .

 

[Julian]

do they have a reverse ?

Most jet boats have a reverse ability. They accomplish this by moving a "gate" or "bucket" down over the jet output to redirect it backwards. This is also how they achieve a "sort of" neutral - they gate/bucket just points the jet flow down. This neutral is hard (impossible) to make perfect - so there is always some creep fowards or backwards.

 

[Julian]

This video does a good job of explaining jet thrust (although all based on Hamilton jet units)

 

[Cobra Jet Steering LLC]

they have a basic reverse

 

[rockhound]

this jet boat was walked away from, the reverse throttle cable was pulled out to replace never finished had one made, waiting for it!
so far has been a fun project Cant wait to put it in the water thanks again for the help
steve