Backfires

[Bruce Bakken]

so my 83 venture royale 1200 having issues starting. Sometimes talks back(backfires) while trying to start. Cliff note version got this 83 last year lots of work into it already had it running right before snow but haven’t gotten it to start well fired over twice but not again. Changed starters to the better one( still sounds like it “misses” or hard turning) and it’s back firing while trying to start. Sat for 10 years before I got it and the carbs need to be done I was just hoping to get some riding in this year before taking the carbs out. Is there a fast way to clean them. What can I do

[luvmy40]

You can try the "Shot Gun" method. Drain the carbs, connect a large syringe filled with carb cleaner(pick your flavor) to the drain port and OVER FILL the bowls with carb cleaner, close the drain and let it soak for a while. It might help, it might not. I've found, with these carbs having set for more than a few months, complete disassembly and thorough cleaning with new gaskets is really the only way to bring them back.

 

The back fire is as likely to be ignition related as it is to be a carb issue. My '83 was missing badly and back firing a lot when I got her. It took a real thorough carb cleaning, new float valves, jet block gaskets, jet block plugs, needle shim kit, bowl gaskets, o-rings, 2new coils, new plug wires and caps, an after market (Ignitek) CDI,  valve shim adjustments and carb sync to get her back to 100% . It was worth every minute and every penny!

Edited June 17, 2022 by luvmy40

[cimmer]

Seafoam might help some but if sitting for 10 years then I would say you need to go thru the carbs and be prepared to spend some bucks. Also make sure you have fresh gas in the tank also. But like Luvmy40 said, check the plugs, caps and wires as there could be some corrosion in there also that will need to address. 

Just a note here also, you will not find a complete carb kit for these bikes as one has yet to be made for them. You will need to piece together the parts from Yamaha and the aftermarket to get everything you might need.

Rick F.

[Bruce Bakken]

I don’t know if I’m at that level to get into these carbs. Let alone find all the actual right parts needed I’m about ready to drop it off somewhere and just have it done, any recommendations for such a place. It would be even better to see or help or have someone help so I can learn. I’m pretty good at most of it and I want to learn it but I’d like to ride in this lifetime 

[luvmy40]

Mike Eykamp(sp?), a member here(eusa1) used to offer a carburetor rebuild/exchange service at reasonable price. I don't know if he still does.

[saddlebum]

This is Cowpucs method which he just posted;

ON BIKE CARB DEEP CLEANING

""Pull the bikes side covers so carb slide covers are accessible, pull the slide covers on the carbs n remove diaphragms/slides (good time to check diaphragms for pin holes/tears), open the drains on the carbs, go to ag store and purchase large syringe for horses, pick up carb cleaner Pick up a spray can of carb cleaner such B-12 or similar quality cleaner. ( If you decide to use  Chem Dip you have to be careful and work fast with Chem Dip!). Inject carb cleaner thru the drain hoses into carbs one at a time until the carb cleaner comes out of the hole that the slide needles go into in carb body one at a time and then close the drain when the cleaner drips out of hole. This will assure carb is filled with carb cleaner. Let the carb cleaner set in carbs for at least 24 hours UNLESS you’re using Chem Dip! With Chem Dip, leave it in for no more than 20 minutes MAX! After sitting for 24 hours, hook syringe back up, open drain and pull cleaner from bowls with syringe and pump syringe to agitate cleaner in carb bowls. After agitating suck cleaner out of carb bowl(s) and  discard. Fill syringe with raw gas, inject raw gas into carb(s) until it comes out of diaphragm needle hole and agitate. Suck raw gas out and discard. Replace carb parts, check the slides to make sure they move freely in the carb bodies, put covers back on over diaphragms. Make sure slide springs are same length, make sure the little o-ring under cover is in place. Close it up, make sure drains are closed, turn on ignition and fill bowls with fuel pump by toggling kill switch until bowls are full (when fuel pump stops clicking). Crank her up and spit check headers to see if its now running on all four while starting with cold engine. You may also like to replace spark plugs and clip off 1/4 inch of each plug wire at spark plug caps if corrosion is present before start it up. Finally sync the carbs when done.""

 

Edited June 23, 2022 by saddlebum

[Bruce Bakken]

Thanks you all are awesome. I appreciate it. I’m going to get at this. Gives me something to do while I find a new cdi box mine is toast with the inside all gross. 

[luvmy40]

7 hours ago, Bruce Bakken said:

Thanks you all are awesome. I appreciate it. I’m going to get at this. Gives me something to do while I find a new cdi box mine is toast with the inside all gross. 

No question here. Go with the Ignitech, programable CDI.