1998 Johnson Venom 225

Javelin400B! · June 03, 2021, 04:45:19 PM

Having issues with my motor. Every once in a while the motor pops and shudders when running down the lake. Just took the lower unit apart and it is in great shape. What else should I look at? I just want to find the problem before it gets expensive.....

Princeton_Man · June 03, 2021, 06:54:10 PM

Quote from: Javelin400B! on June 03, 2021, 04:45:19 PM
Having issues with my motor. Every once in a while the motor pops and shudders when running down the lake. Just took the lower unit apart and it is in great shape. What else should I look at? I just want to find the problem before it gets expensive.....

Welcome aboard!
First thing I'd suggest is do a compression test. If you have a wrist pin coming out of the side of a piston and hitting the cylinder, that would explain the pop and shudder. If that's happening, it's scoring the cylinder and that will show in compression. A buddy of mine had that very thing happen with his Yamaha. Ended up shattering the piston and he had to have a new powerhead.

Mike Cork · June 04, 2021, 08:08:56 AM

Welcome aboard... Love the screen name, I wanted a Javelin 400 soooo bad back in the day

awesome fishing platform. Back to the motor. Definitely a compression check to make sure it's not a mechanical issue. Then start checking electrical. A coil pack going bad can be hard to isolate without buying a new one and rotting them out.

Does it only do it at certain speeds? Are we talking WOT?

Javelin400B! · June 04, 2021, 12:19:31 PM

Did a compression test and everything checked good. I'm going to put a bore scope in each cylinder and check for scaring. I'm going to order new coil packs, it wouldn't hurt to change them, not sure how old they are. I just purchased the boat last year

Donald Garner · June 04, 2021, 12:28:14 PM

Javelin400B

Welcome to the UltimateBass Family we're glad you're here. When you get the chance drop some pictures of your Javelin over in the Stratos Board.

Javelin400B! · June 04, 2021, 12:28:26 PM

Boat starts and idles fine, problem occurs when getting up to WOT. I'm not sure if I'm getting full power or not, I've been hesitant to push it too hard after it acted up. I was between 4000-5000 rpms when it started happening.

Mike Cork · June 04, 2021, 03:33:03 PM

Bore scope is aways an awesome idea since you have that ability.

Does it matter how warm the motor is? I once had a power pack that would only fail after it was good an hot and then it was still intermittent. Let us know what the scope reveals.

Princeton_Man · June 04, 2021, 04:07:29 PM

I may have misunderstood. When you said it pops, I was thinking mechanical pop.

Javelin400B! · June 04, 2021, 04:51:48 PM

I thought it was mechanical, that's why I went through the lower unit. It's hard to tell because it only happens when under load. I ordered a new power pack and new coils. I'll replace all of that and then test it. Hopefully that fixes whatever is going on.

Oldfart9999 · June 09, 2021, 07:02:28 AM

If the coil pacs don't fix it then it will most likely be fuel, could be anything from a good cleaning to some rebuilding, hope it's an easy fix for you.
Welcome to the site!!!
Rodney

Javelin400B! · June 15, 2021, 04:23:00 PM

Replaced coil packs and power pack. The motor still has a miss at times, though not as severe, and only when the motor is trimmed down, before I take off. I'm still not getting more than 3000 rpms on my hole shot. This is getting frustrating and expensive.

Princeton_Man · June 16, 2021, 07:02:10 AM

When was the last time the ignition wires were replaced? If it only runs a little rough or misses trimmed down, there could be something in one of the fuel bowls or maybe some water in an inline filter. Sometimes, the least expensive route is to take it to an experienced mechanic. Of course, you have to have a qualified shop/mechanic you can trust because there are shops that will just do the same thing you're doing now and rack up a huge bill.

Javelin400B! · June 16, 2021, 07:47:57 AM

We have only one mechanic in my area that works on the older evinrude/johnson motors. When I bought the boat I took it to him to get this motor running properly. A couple thousand dollars later, I pick the boat up and it has never run 100% right. He's backed up until at least August and I have tournaments to fish. If motors were readily available, I'd just replace the whole motor and fix the problem. Going to change the fuel filter and check the plugs, I might be running a little rich. The only other thing I can think of is maybe a bad trigger. But that sensor assembly is expensive and a pain to change out.

Mike Cork · June 16, 2021, 05:43:16 PM

You've mentioned fuel. Several things in the fuel system can cause hard to find aggravating problems and are not to terribly expensive to replace... Although once you're in this deep, everything seems expensive.

I've see a check valve in the bulb create issues. Even had a dirt dobber block a vent and caused all kinds of top end sputtering problems.

Javelin400B! · June 22, 2021, 07:48:24 PM

Finally got in at my mechanics shop today. Apparently it was slipping when in gear. He adjusted my shift cable and I test ran with no issues. Could still be something with the clutch dog getting weak, but for now it seems to be fixed. Pretty crazy that it was that simple.

Javelin400B! · June 28, 2021, 02:11:40 PM

That fix lasted 1 trip. I have found a 2006 Evinrude 225 H.O., does anyone have experience with these motors? Around 400 hrs

Mike Cork · June 29, 2021, 08:01:12 AM

No experience with those... I know when the H.O. came out a lot of the Evinrude Pros would talk highly of them during interviews. Said they had the best lower unit in the market... I've always been a Mercury Guy.

Crazy about the Clutch Dog I don't know if I would have gotten to that as an idea.

Princeton_Man · June 29, 2021, 10:53:13 AM

Quote from: Javelin400B! on June 28, 2021, 02:11:40 PM
That fix lasted 1 trip. I have found a 2006 Evinrude 225 H.O., does anyone have experience with these motors? Around 400 hrs

It's a great motor! As far as buying it, treat it like any other used outboard. Do a compression check on all the cylinders, download the logs from the computer (They'll tell a lot), check the lower unit oil and do both a pressure leakdown and vacuum test. Find an Evinrude shop and have them look up the serial number, they should be able to get all maintenance records up to at least the 300 hour service.

There were a lot of design changes and improvements that took place between 2006 and 2015. Service bulletins had shops implement some of those changes and mods during service visits. A lot depends on how the original owner took care of service.

Without knowing anything about the fuel used or how well it was maintained, I'd have the injectors cleaned before running down the lake. That could prevent burning a piston. I'd also have a complete service done including lower unit and water pump.