1988 johnson 175 v6 vro wont start on its own

[llraptorll]

hi all,im new to boating,just got at 1989 chaparral with a johnson 175 v6 vro,the engine does not start on its own,it only starts when i spray starter fluid directly in the carbs,runs for 2 to 5 seconds then dies,i removed the fuel lines to all three carbs and pumped the primer bulb and got fuel to all three lines,also i kept pumping the bulb and was able to run it for 20 to 30 seconds running rough while i was holding half to full throttle but as soon as i let go of the throttle it stalls out,i checked the compression and got 100 psi all cylinders,spark plugs were very fouled so i got new plugs,i removed all three carbs and cleaned them really well,new primer bulb and fuel line to engine still same condition,any ideas guys would be very helpfull....thanks

 

[j_k_bisson]

Re: 1988 johnson 175 v6 vro wont start on its own

Clean the idle orfices in the throttle plate behind the carbs. This is where the fuel comes out off. They are more than likely plugged. Also take off your carbs and soak them in varsol and scrub them really good. Might want to stop by Harbour Freight and pick up a spray gun cleaning brush kit. Helps with scrubbing all the tubes and passages and orfices clean. Make sure carb cleaning fluid comes through every orfice before reassembling. Make sure none are clogged with a peice of wire stuck into each hole.

 

[llraptorll]

Re: 1988 johnson 175 v6 vro wont start on its own

hey,thanks for the advise,i removed the carbs and cleaned the idle orfices soaked the carbs an scrubbed them really good,but still the same condition,maybe the vro pump is not delivering the fuel and the fuel only gets there when i pump the bulb,and if so how do i make sure the vro fuel pump is ok?...thanks again

 

[Monte1961]

Re: 1988 johnson 175 v6 vro wont start on its own

kits are available! I blocked mine and use mixed fuel/oil. Most marinas have it pre-mixed already so i don't have to worry if vro pump is working or not. It's not worth burning up a motor to me if the vro pump takes a sh*t. 50:1 fuel ratio, using any and all fuels with no issues. And why not pull any and all core plugs and soak in carb cleaner overnight? Then spray off with fresh water and blowdry with compressed air! Note I do believe the 175hp have 3 carbs. Two the same idle orifices and one is different.? The different one goes in top carb!

 

[llraptorll]

Re: 1988 johnson 175 v6 vro wont start on its own

Thanks Monte and bison for the advise really appreciate it

 

[llraptorll]

Re: 1988 johnson 175 v6 vro wont start on its own

what kind of fuel pump do i need so i can replace the vro pump and premix any part numbers would be greatly appreciated also if i can get directions on hoses to plug and is the pump pulse controlled or is it just electric?thanks

 

[j_k_bisson]

Re: 1988 johnson 175 v6 vro wont start on its own

You can rebuild the pump you have with a rebuild kit. But you will have to run premix only afterwards. They kits are only for the fuel side of the pumps. You can look up the parts numbers at http://www.maxrules.com/fixomcvro.html Here is the site for the dissassembly and assembly instructions http://www.maxrules.com/graphics/VROpics/ .

I used kit numbers 436095 and 435921. These where for the 1998 and older vro pump rebuild kits.

 

[llraptorll]

Re: 1988 johnson 175 v6 vro wont start on its own

thanks bisson ,really informative advise and web sites,also i have one more question can i use an aftermarket fuel pump and not the vro style,and also how are those aftermarket ones ran electric or what?thanks again for the advise you guys are awsome

 

[emdsapmgr]

Re: 1988 johnson 175 v6 vro wont start on its own

The 83 and older V6 engines ran a pair of inexpensive, dual mechanical fuel pumps. A pair of them will easily supply enough fuel to run your 175. Each of them required a pulse port on the side of the block. Your VRO engine has only uses one pulse port, possible located mid engine on the front port side. You may be find the the factory has plugged a similar hole just under the existing pulse hose barb. If so, you can remove the factory plug and screw in a second hose barb. If you can accomplish this, you can run a pair of the old style mechanical pumps. Keep in mind that the two pumps are different part numbers. They run around $95 each. Could be a reliable, inexpensive solution.

 

[llraptorll]

Re: 1988 johnson 175 v6 vro wont start on its own

thank you very much emdsapmgr,very usefull info,one other question can i run electrical fuel pumps or not?thanks again for the info

 

[Fed]

Re: 1988 johnson 175 v6 vro wont start on its own

If you prime it up with the fuel bulb until all the carbies are full it should run on idle for 2-3 minutes before it runs out so there's probably nothing wrong with your fuel pump from your description.

 

[emdsapmgr]

Re: 1988 johnson 175 v6 vro wont start on its own

Check the fuel primer solenoid to make sure it is suppling fuel to the tops of the carbs when you turn the key to run and push in on the control box key switch. If you don't get fuel pulsing into the small hose barbs on the top of the carbs, you will have a really hard time getting the engine to start when cold.

 

[llraptorll]

Re: 1988 johnson 175 v6 vro wont start on its own

hey emdsapmgr and fed thanks again for additional info guys,exactly where is the fuel primer solenoid located?and again sorry im pretty new to this,any pics or description would be ghreatly appreciated.....thanks

 

[llraptorll]

Re: 1988 johnson 175 v6 vro wont start on its own

and bisson thank you too for your info you guys are really helpful to a rookie to boating like me

 

[j_k_bisson]

Re: 1988 johnson 175 v6 vro wont start on its own

The primer solenoid is a round cylinder with a square head on it. It is bolted to the air box in the lower corner right under the VRO pump on a 200/225hp.

 

[llraptorll]

Re: 1988 johnson 175 v6 vro wont start on its own

ok thanks bisson i think i found it but its on the left side of the motor and it has a red lever i think for manual choke am i correct?

 

[emdsapmgr]

Re: 1988 johnson 175 v6 vro wont start on its own

The red lever needs to be parallel to the length of the solenoid for normal operation. It can be turned (That opens up the scrader valve.)in order to inject fogging oil or Engine tuner direct into the carbs/engine. A nice feature.

 

[j_k_bisson]

Re: 1988 johnson 175 v6 vro wont start on its own

Fogging oil or Engine tuner? It hooked up to your fuel system. It is a different style of choke. When the valve is pointed down the length of the cylinder it is closed. When it is pointed/rotated up it is manually open. The manually open is for pull start feature. Not that I think I could pull start one of these.

When it is closed, you press in the key and it will active the solinoid and allow fuel to pass into the intake right after the Reed Petals. You wait 5 seconds for the fuel that is passed to evaporate then you turn over the motor. It should start. Keep in mid to keep holding/pressing in the key until it catches/starts. They you intermitantly press to keep running until it warms up. Basically a choke.

Now if you think you have an air leak this is on place that it can happen. The line that are hooked to it and the gasket and oring do go in them. I also think they are not ethonal rated orings and gaskets. There are no clamps on these hoses either. Zip ties or other wise. Might want to check it out after rebuilding carbs and cleaning throttle plates

 

[llraptorll]

Re: 1988 johnson 175 v6 vro wont start on its own

thanks bisson and emd,great info i will be checking either todasy or tomorrow and ill get back to you with results