Kawasaki v-twin has trouble starting

[01rangerxl]

During some Craigslist perusing a few weeks back I ended up with a non-running Great Dane Scamper with a 15 HP Kawasaki FH451V v-twin engine. It's recoil start and the choke is incorporated into the throttle cable. There is no fuel solenoid on this carburetor, but it does use a vacuum fuel pump.

Basically the PO broke the recoil starter, then let it sit outside for a while. The fuel system was funky. I cleaned up everything as best I could, but there still could be some junk in the carb. Fuel lines are clear, and while I didn't soak the carb, I cleaned it thoroughly.

I got it to run, but it only wants to start with carb cleaner or ether. You can pull the recoil all day and it will not start on its own, spray one shot of ether and it cranks right up. Runs very strong with the PTO engaged, but sometimes surges at idle with the PTO off. That has improved somewhat the more fresh fuel runs through it.

I used to work for a company that repaired this stuff, but in this situation we would have just slapped a new carb on and called it a day. I don't want to drop $185 on a new carb if I can avoid it. Is there a certain area of the carb I should focus cleaning efforts on to resolve the issue with starting? I have not made any adjustments to the control panel. It probably hasn't been touched since leaving the factory, so I didn't want to mess with it without having a clue about what I was doing.

Worst case I will just keep a can of ether handy. Once it's warmed up it starts on the first pull.

 

[wally6934]

I have fiddled with carbs like this several times. Even after a good soak in an official carburetor cleaner they still run poorly or not at all. All you can do is total carb disassembly and try to get a fine wire in all orifices and clean them out. From my research some carbs have passages that are simply not accessible as they are cast right in the housing. Sometimes the carb has the little lead (welch) plugs that can be removed to get at more passages, i think the replacement plugs are included in a rebuild kit. I never fooled with them because i was not sure how to remove and reinstall them properly. If anyone knows how without special tools please add info to the thread.

Another thing i learned is that when water is involved that you are now fighting mineral deposits. The only way i got rid of them was to use a diluted toiled bowl cleaner. I think i did a 50 50 mix or 25 cleaner 75 water. I only let it soak for 5 min as it cleans very fast. With this method I have gotten carbs that have been rained on for years to at least start and run but a little rough.

Another thing you can do is use an ultrasonic cleaner. This will clean much better than a weak chemical soak will.

 

[JimPghPA]

Does it have the plastic intake tube(s)between the carb and the cylinders? There was a thread here on BITOG within the last 10 days where someone showed how those intakes crack along the seam. The air leak is not easy to find unless you know to look there.

Other than that I would soak the carb even if you have to go out and purchase the one gallon paint can with basket Gunk carb cleaner set-up. If you soak it be sure to remove any welch plugs, and mixture screws and blast out all passages.

 

[JimPghPA]

YouTube has videos about removing and replacing welch plugs.


Search for "carburator rebuilding".

 

[01rangerxl]

This one has a metal intake manifold with no cracks. There is a plastic spacer, but it's not cracked either.

There are a couple welch plugs on the carb, so it sounds like further cleaning needs to be done. I just sprayed it down with carb cleaner and ran wire down the passages I could get to. I thought about getting one of the Gunk soaking kits, but didn't want to have to remove the little plastic pieces on the carb. The carb did have water damage. The gas turned to varnish and there's corrosion too.

I looked for a rebuild kit for this carb, but couldn't find one. The parts for it are not very cheap which is why I have been trying to fix it with chemicals.

I'm pretty sure the oil and filter were original! The oil was pitch black and the oil filter had rust where the throttle cable rested against it. It was also a Kawasaki filter. It's filled with some Castrol GTX 5W30 I had sitting around and a generic oil filter for now.

 

[JimPghPA]

Be sure the idle air circuit hole is not clogged up. It is the little hole on the floor of the air passage. It is just after the choke plate. You have to remove the idle screw to blow this passage out with carb cleaner.

 

[01rangerxl]

Originally Posted By: JimPghPA
Be sure the idle air circuit hole is not clogged up. It is the little hole on the floor of the air passage. It is just after the choke plate. You have to remove the idle screw to blow this passage out with carb cleaner.



I need to check that. I did not clean this out when I had the carb off.

 

[JTK]

Wow that's a great find and an awesome mower!

Engine is not trashed so that's a good thing.

Good Lord those carbs are expensive! I see them at ~$190 online. I'd study the parts diagrams, take it apart, soak it again, etc.

Joel

 

[JimPghPA]

There is a good online carb parts store called PartsTree.

For the Tecumseh carbs there are two kind of idle screws. If it has a black plastic cap it is not adjustable and is turned all the way in, do not over-tigthen it.

For other type you adjust to the minimum and maximum where it runs good and leave it in the middle.

 

[JimPghPA]

Sometimes you have to remove the carb bowl to get to one of the welch plugs.

 

[JimPghPA]

After you get it working good when you put it away at the end of the season, remove the carb bowl to get the last bit of gas out after you run it dry, and then spray some WD-40 on all parts including the small passages.

 

[01rangerxl]

Yeah one or two of the welch plugs are inside the float chamber. I know I will be taking the carb off again at some point. Luckily it's straightforward on this engine.

It has a screw on the float bowl to drain it, but it was clear that this screw had never been removed. I had to use a Scotch-Brite pad to clean up the bowl and bolt.

The good thing is it has been running a little better each time I use it. Fresh gas running through the fuel system seems to be helping by itself.