150 johnson not getting to 5500 rpm

[satman7475]

hay guys, ive read alot of good advise here. i hope someone can help me, i need it. i have a 150 johnson faststrike. at first it would not get up on plane. everytime i give it full troddle it just gives out and cuts off, okay a simple tune up right. well after 200 dollars and a month got it back from mechanic. still did the same thing. i did post a while back. ranged from things like check for fuel resrictions powerpack stater timing cheched all that, keep in mind in not a boat mechanic but i do have car mecanics exp, but two different things all togather.so after i still could figer it out back to the machanic after a nother 5 months and 775 dollars he assured me it was fixed. so excited whet out to the lake this sat. so dissapointed, it was even warse. it alwasy and has always cranked up and even runs good untill 2000 rpm it just hangs up right there and no further. well we finally head back in ready to sell the damn thing and then it finally got up to 4000 rpm but using the tilt and trim. the motor was getting up to 5500 rpm before the machnic even touched it.so what would make it hang up at 2000 rpm all day then finally get to 4000 rpm but not up to 5500 rpm like before.im sorry for the long post im just frustrated and tried to give youll as much info as i could. thank you for any info.

 

[R.Johnson]

Re: 150 johnson not getting to 5500 rpm

5 months to do something wrong, I can usually do that in seconds. I would certainly start with the basics. But the thing is! that engine once ran at 5500. First! I would go through the linkage, stator plate going to full advance, " my first thought" carb's are going to full open, voltage reading on the ignition system through out the full range, vacuam, pressure reading on the fuel system. That mechanic certaintly checked compression. For $975 , he would have been sitting in the seat beside me on the water test.

 

[DJ]

Re: 150 johnson not getting to 5500 rpm

satman,<br /><br />You are obviously not getting full power out of all six cylinders. It could be ignition, fuel (carburetion) or mechanical.<br /><br />Check the compression on all six first. It should be over 100 psi and with 10 psi of each other.<br /><br />Look at the spark plugs, do they all look the same? By the way, what plugs are in it? Should be Champions-ONLY!

 

[Solittle]

Re: 150 johnson not getting to 5500 rpm

I hate to ask the obvious question but is your mechanic reputable? Those who are usually stand behind their work.<br /><br />If you decide to fiddle with this yourself start by getting a shop manual - then follow DJ's advice on compression check & plugs. At this point you need to focus on troubleshooting to narrow down what is & is not going on. We don't have enough info yet to attempt much more than a wild guess.

 

[satman7475]

Re: 150 johnson not getting to 5500 rpm

thanks guys i have a friend that knows alot more than i do i suppose to meet up with him later this week. he seems to think like you R. JOHNSON, linkage vacuam hose, didnt think about carbs not opening all the way, will get him to take a look. i first thout of that DJ

 

[satman7475]

Re: 150 johnson not getting to 5500 rpm

sorry i messed up again. DJ thanks i did thank about the plugs to, but if the plugs were bad why would it get high rpm in rev and not in forward, but yes they are champions and new at that, but thats somthing i can do tomorrow and let you know if they all look the same or not. and yes SoLittle i shoud have done my homework i was lokking for somone who could fix it fast wasnt thinking if the mecanic was any good or not. i mean he says he stands behind his work but he has had it twice and seems to get worse and worse, i dont think i want to take it back to him.

 

[satman7475]

Re: 150 johnson not getting to 5500 rpm

well if you guys are still there i checked the plugs all look the same not too black gray oily just right. pulled the boot away from plug and saw sparks fireing so i know all cyclenders are fireing., thats a relief. still havent cheched the psi yet, no tool. will get that done later this week, will let you know thanks.

 

[mhelgeson]

Re: 150 johnson not getting to 5500 rpm

I have no idea if this will help at all, and it's probubly already been dealt with.<br /><br />I had a Suzuki 30hp, it did this exact same thing. Nothing more frustrating than having it wide open doing 7mph. I adjusted the trim and installed a hydrofoil = 15mph... I finally got frustrated and cleaned the carbs for the fun of it, the #3 carb was bone dry, injector 100% crusted over (hard), and the float was stuck shut from gunk in the bowl... the other 2 carbs were perfect. This is only from 60 days in storage tell I could go get it. Cleaned, installed = 30mph (about right from when it was new) and 1 happy fisherman.<br /><br />Probubly not a lot of help, but I feel your pain. Good luck.

 

[satman7475]

Re: 150 johnson not getting to 5500 rpm

thanks LostNORSEMAN i far as i know the cards have been cleaned, had not had much time to fiddle with it but thats the next thing iam going to check, the carbs to see if there clean, opening up all the way etc.. thanks for the input

 

[Chum Slick]

Re: 150 johnson not getting to 5500 rpm

I would surely like to know who your mech is so I would know to avoid him. I have heard of some mechs who clean carbs by spraying carb cleaner through them and that's it. The only way you can thouroughly clean carbs is to remove them, disassemble, check and clean all jets, linkages, and bowls. It doesn't take much to gum up jets which can cause a lot of problems with acceleration and rpms. Could also be power pack or ignition coils. If your motor runs hot you will automatically loose power to two of your power packs which will limit rps to around 2000. This is a built in safety device to keep from destroying your motor. Your mech should have checked everything mentioned if he knew what he was doing. <br />One more thought, do you have a single tank or double tanks? I have seen in some cases if you have double tanks and both fule lines run into a common tee with individual valves both valves have to be open or you will draw a vacuum on one fuel line which could cause fuel starvation. Just a thought.<br />Good luck and let us know how things turn out.

 

[bonitoman]

Re: 150 johnson not getting to 5500 rpm

What year is your engine and how big of a boat is it on? Also, what size prop are you running?

 

[blfdengr]

Re: 150 johnson not getting to 5500 rpm

Satman7475<br />I also have a 1993 Johnson 150 Fast strike. This exact same thing happened to me besides the big pay out! It ended up being the Power Pack. The power pack has an emergency protection system that will not allow it to get above 2000 RPM but is also telling you that the pack is blown. That is what my manual said to. I changed it out and it runs fine. I am now having a pump problem 3 years latter.

 

[satman7475]

Re: 150 johnson not getting to 5500 rpm

hay guys sorry i hadnt posted in a while been so busy at work. well i read your last post and i do only have a single gas tank. the year of my motor is 94 the boat is a stratus 17 foot, prop is a 14 1/2 by 24 pitch. you know thats the first thing the meck. thought it was the powerpack, but said he checked it out and it was good, but i think he was just putting parts on left and right hoping to fix it. i dont know what to do i dont want to put back in shop and fork out more money. dont know enough to fix my self, cant enjoy it running like it is. my friend that was suppose to look at it for me,,,, cant get in touch with him and iam not one to keep bugging the hell out of someone. but i thank everyone for their input.thanks