My poorly carbureted Road Toad

[spudman]

Hey Guys-
Well, upon taking my model 99 Road Toad restoration project for a ride today, I immediately noticed that it is running terribly. My guess is that it is running very rich. When I took apart the carburetor and cleaned it in an ultrasonic cleaner several weeks ago, I decided to replace everything internally. When I called Paul at SH, he suggested that I go with the model 02 Road Toad jetting, as Hodaka had greatly improved the jetting on the later models. So, that's what I did. I'm running the stock Mikuni VM26 SC carburetor with a 160 main jet, a 5EL9 needle with the clip in the 4th groove, a #30 pilot jet, a 2.0 float valve seat and the air screw 1 1/2 turns out from fully seated. I also replaced the floats. As soon as I turn on the fuel petcocks, within a minute or so there are drips of fuel coming out of the overflow nipple on the bottom of the float bowl. I thought at first that this may have been due to a faulty float valve seat, so I put a brand new one in. Nothing changed. The bike starts on the first kick (cold) and idles fine. Riding it through the gears though provides only certain times when it seems to be running smoothly (maybe 3rd or 4th gear at about 1/2 to 3/4 throttle). The rest of the time, it is running very ratty. Once the bike is warmed up, it will die completely as I am coming to a stop and am downshifting into first. It will not start then with the kick-starter; I have to hop on (hopefully with a downward incline!) and pop-start the bike. I'm at a loss as to what to try next here. Any ideas or suggestions are appreciated!

[Darrell]

Check that the float level is correct. Sounds like the float has to rise too high to close the needle.

[Dale]

The overflow issue needs to be resolved first. There is either something wrong with the valve and seat or perhaps it is just the float adjustment.

Once that is fixed, make a masking tape gauge and pointer on your throttle housing with marks for 1/4, 3/8, 1/2 and 3/4 throttle. This is the easiest way to determine what jetting ranges need attention. The 160 main should be at least close for a Road Toad. Adjust your air screw for the best idle. Then if it is rich at 1/4 your slide would be suspect. However 2.0 should work for most Toads. Then if you are rich from 3/8 to 3/4 your needle needs lowered. Move the clip from the 4th notch to the 3rd. Finally, if you are rich at Wide Open Throttle then you can reduce your main to 150. Be careful not to get it too lean and sieze it up. It takes patience and practice.

[dirty_rat]

A couple of other questions...what elevation are you at? Also, is you ignition system in good shape (good points and condenser)? Is the air cleaner in good shape and not clogged somewhere? Is the pipe clean and has no obstructions?

[spudman]

Thanks for the suggestions. Darrell...the only float height "measurement" I can seem to find anywhere for my bike is to adjust the float arm so that it is level with the gasket surface on the carburetor body with the carb inverted and the floats just resting on the spring mounted float needle. This is how mine is currently set.
dirty_rat - I'm in southeast WI at 932 feet elevation. I just put in new points and set the timing, but did not install a new condenser. I cleaned the foam air cleaner element in warm soapy (Dawn dish detergent) water and then sprayed it with some of that red K&N aerosol air filter oil that I had from back in the day.
Dale - Thank you for the idea as to how to isolate each individual "system" of the carburetor. The thing is, with a fresh bore and new piston, rings, etc....I don't understand why the factory "base" settings that Hodaka recommended for the model 02 wouldn't have the bike running much better than it does. I guess that does sort of point to the float height issue, seeing as the valve and seat are both brand new. I'll work on things this week and see what I can come up with. Thanks again!

[Dale]

I can see why one would think so but that has not been my experience. I run 2 Road Toads and both use a 5EJ13 on the 3rd notch with a 170 main and a rich 50 pilot. Work slowly on one area at a time and you will get there.

[Bullfrog]

That IS the correct float level setting for that bike and carb - no measurement needed (or given). But your float valve is not working properly. Grunge? Got an inline fuel filter?
Ed

[spudman]

Yep Bullfrog...an inline filter is present and clean and the float valve and seat brand new. Guess I'll look at it with a magnifying glass for any possible issues, but since the carb was doing the same thing before the cleaning & rebuild (dripping from the overflow nipple), I'm thinking it's something other than that valve & seat (like the aforementioned float height).

And Dale - Ironically, the bike ran really good for the one time I took it around the block after I bought it a few months back (before I started the restoration project which included a the bore job, new piston, carb rebuild, etc.). And you know what the jetting was then? You guessed it...EXACTLY what you described above!! I'm thinking I should have left it alone, but Paul had suggested the updated model 02 jetting that Hodaka used in the later models, so I went with that thinking it would run even better. Oh well....back to the drawing board.

[Dale]

I think Paul's suggestion is the correct one. There were issues with the early Toads that led to different jetting. The 5EJ13 was one of those changes. The 02 Toads then went to the 5EL9.

It could be that you would end up on the 2nd notch rather than the 4th. Work slowly towards your adjustments making one small change at a time.
Dale

[Dale]

Here is a link that should get you to an article titled "Tuning Mikuni Carbs" that was written by Harry Taylor. It is a good read and might prove helpful in understanding the role that each carb element plays in the overall tuning. I hope this helps.
http://www.strictlyhodaka.com/Articles.asp?ID=252

[matt glascock]

Spudman, I had a similar issue with not one, but two bikes. A Toad like yours and a Dirt Squirt. Brand new float valves and seats for each. The two problems were damage to the brass floaters with small holes that allowed them to fill with gasoline thus becoming sinkers on one and binding of the float mechanism on the other disallowing freedom of movement. If you have the brass floats, shake them to be sure they are not full of fuel. You can also hold them under fuel and look for bubbles. If that's the case, allow them to drain completely and solder the holes. I had to drill very small holes to get them to drain completely because, well, I'm impatient. Don't go crazy with the solder. If your carb has the two individual black plastic floats, make sure they don't bind on the posts.

[BrianZ]

I have seen numerous people with good intentions "over oil" their air filters. When I oil a filter I saturate it with foam filter oil and then squeeze out the excess. Check the instruction supplied with the filter for the correct oil and application instructions. Try running the engine without the filter (stationary) and see if it runs better.

The issue with your float bowl overflowing needs to be corrected. Make sure the float moves easily on the pivot pin. Try dropping the float in a small container of gasoline to see if it indeed floats. A crack or hole will let gas inside causing it to sink.

[Bill2001]

And also the float level/fuel level may not be adjusted too high. I've seen some carbs leaking from the overow tube itself. If it is loose where it is pressed into the float bowl. Or water gets in the overflow tube and it freezes and cracks. Or tbere is fuel drippage from where the fuel inlet fitting is pressed into the carb body.

[spudman]

Thanks for all the additional suggestions guys! I took the carb off and my mechanic and I took it apart tonight. The brand new float valve and seat are fine; we ruled out problems with those by a simple vacuum/suction test. The float level was already set a bit low, and we moved it even a bit lower. When we reassembled the carb and supplied fuel to it, there was no leak at the overflow nipple. I'll try to get it back on the bike tomorrow or Wednesday to see how it runs.
Dale - I too think Paul was correct regarding the model 02 updated jetting. I suspect this issue was likely with my overflowing float bowl more than anything else. That said, when I ordered the 5EL9 needle from SH, I ended up getting one that Paul said he pulled from his personal bike because Mikuni no longer made this needle. I honestly don't know how or if these things "wear", but I really didn't like the idea of putting something used into the carburetor...not knowing anything about how old it was or how long it had been used. To be safe, I just ordered a NOS 5EL9 on eBay a few minutes ago. They're out there yet if you hunt for them. I am curious though...why do you say that I may end up on the 2nd notch instead of the 4th? Just wondering. Thanks also for the link to the "Tuning Mikuni Carbs" article! It looks like it was actually written by Leon Wilbanks, but whoever wrote it...it looks like it contains all I will need to know!
Matt Glascock - I have the two individual plastic floats. I just replaced them, so they are brand new. No binding on the posts whatsoever, but thank you for the tips!
BrianZ - My mechanic suggested the very same thing today. I plan on running the bike with the airbox cover in place but with the filter element removed to see if there is any difference. I have the stock Hodaka foam filter. I cleaned it very well to remove all the old oil and then let it dry completely. I then sprayed a light coating of K&N aerosol air filter oil on the foam element. Now this was a VERY old can of filter oil, but it sprayed evenly out of the nozzle and looked just as it did back when I used it on my K&N filters on various bikes I had owned over the years (red). That said, I believe this was designed for the cotton/fabric "pleats" in K&N filters. I'm a bit worried now that it may have somehow clogged the foam element. If the bike runs good with the filter off, I'll clean it again and just use what Hodaka recommended in the owner's manual (SAE 30 motor oil). I'll update this when I get the carb back on the bike. Can't wait until I'm retired and don't have this darn 8 hour workday to keep interfering with things!

[spudman]

Funny you should mention that Bill! I got home from the mechanic's shop tonight and was planning on connecting the fuel line to the carb to check again for leaks when I looked down at the carb and the fuel inlet fitting was gone! It was back at the shop...stuck in the fuel line we used there. My mechanic Gary mixed up a small portion of JB Weld and we applied a little to the circumference of the base of the inlet fitting and then pressed it back in place. I never saw it leaking in the past, but it shouldn't have been that loose to begin with and there were signs that someone had tried to "seal" it with silicone once before. All is sealed up now; just have to wait the recommended 15 hours for it to dry.

[Dale]

... I am curious though...why do you say that I may end up on the 2nd notch instead of the 4th? Just wondering...

To clarify my comment on the needle clip position:
That was just my guess with using the 5EL9 needle. You said that you are currently on the 4th notch. I assume that you mean the 4th notch down from the top of the needle. This would put the needle next to the richest possible position. So if you are too rich at mid-throttle (3/8 to 3/4) then you would move the clip to the 3rd notch to lower the needle and thus make the mid-throttle leaner. If still too rich in the mid-throttle then you would move the clip to the 2nd notch which would be next to the leanest position. The target is to use a needle that works on the 3rd notch. The 2nd notch and 4th notch are acceptable. If 1st or 5th notch is required, then typically you would look to either change the needle jet (nozzle) size or go to a different needle. This is my belief and others might have some differing opinions on this topic...
Dale

[Dale]

One additional thought. When you get your new 5EL9 needle, you might want to use your digital calipers and compare it to the other 5EL9 that you have. Not all needles are created equal. You can download spec sheets for mikuni needles to get the correct dimensions. As an example, I have 5 different 4E1 needles and only 2 of them match the spec sheets. Just be aware of this possibility...

[spudman]

Thank you for that information Dale! The factory specs for the model 02 Road Toad actually call for the clip to be placed in that 4th notch down from the top of the needle. I figured I'd start with that and go from there. Thank you as well for mentioning the measuring of the needles. I'd like to assume that a 5EL9 is a 5EL9, but I now know that might not be the case! Unfortunately, I seem to have solved one problem but developed yet another. The float bowl overflow no longer leaks. BUT...I can't even get the bike to pop now. I did absolutely nothing with the ignition...just removed the carb and adjusted the float level. So...I don't know if the points slipped or what, but I can't get it to pop by kicking it or bump starting it. Can't see if I have spark right now (too bright outside) so I'll have to check later after dark.

[Dale]

Did you get the floats in upside down? That will shut off the fuel supply. It is pretty easy to make that mistake.

[spudman]

Dale - Floats are in correctly; we were very careful when reassembling the carburetor. I also smelled gas as I was kicking the bike over, so I think this is probably electrical in nature. I'm guessing it's my points, as I did end up checking for spark late last night and I have NONE. I'm going to clean and adjust the points and also check my kill switch which seemed to be a bit "sketchy". Hopefully, I'll find something "obvious" and it will be a quick fix!

[Bullfrog]

Two comments:
1) There is no need - and some risk - to setting the float level lower than recommended. If things are "right" there will be no leakage at the recommended float level.
2) On at least two occasions wayeeee back in the day, I rode a Wombat (toaster tank model) from Athena to Weston for lunch. Had a fine lunch topped off with pie and ice cream, then went to the bike . . . and there was no spark. A strip of business card was used to clean the points . . . and then I rode back to work. In case you were wondering, yes, I had pie and ice cream on both occasions.
Ed

[spudman]

Thanks for the tips Ed. We barely bent the float arm tang at all, but yes...it was ever so slightly off from being parallel with the gasket surface. I guess I don't know for sure if that is what was causing the problem with the overflow nipple drip, but I do know that it no longer exists. Since the "no spark" issue seems to be unrelated and purely coincidental, I'll start a different thread now on that topic. As for pie and ice cream...there is never a bad time for either!

[spudman]

Finally got everything sorted out this weekend! I ended up with the needle clip in the third (middle) groove of a 5EL9 needle, 160 main, 27.5 pilot and the air screw at 2 turns out. Smooth power delivery at all throttle openings and 1-kick starts are about all I could ask for. Amazing just how far off my setup is though from Hodaka's "advanced jetting" stock settings for the model 02 Road Toads.

[Dale]

It is good to hear that you got it dialed in. I don't think I would consider your end result as that "far off" from the stock settings. There are so many variables that affect jetting on any individual bike, that it seems pretty close to me. The overall condition of the ignition, exhaust pipe, air cleaner, fuel and compression all impact jetting not to mention the condition of the carburetor itself..

Have fun riding it now that you have it starting and running properly.

[spudman]

Thanks Dale! Yeah...I guess you're right. There really are so many things that go into the mix here. In any event, I'm glad it's running well now, as if I had to take that carb off one more time I'd have pulled the few remaining hairs out of my head! Thanks to you and everyone else for the helpful tips.