83 CB1100F question

MB-5 Joined: Mar 27, 2019 Posts: 4 Location: Philadelphia

Hey guys, fairly new on this forum. Seems like it's the only one for my bike lol. Anyway, I have a 1983 CB1100F with 15k miles. It;s in fair condition given the year and the mileage. Carbs were rebuilt and I had it running early this year. My issue was the gas tank was filled with rust. After many treatments I got the rust out to the point pin holes were all over the tank and it leaked the gas. Motor also didn't run perfect. Had some backfiring coming from the right side exhaust however the bike would idle and I have a video of it running.

Long story short, I wanted some guidance. Should I restore this bike, make it a cafe racer or just sell it to someone who knows what they're doing? I'm mechanically inclined and just have the bike sitting and would like to do something with it, just dont know what is worth doing with it. Let me know what you guys think!

Posted: Tue Dec 10, 2019 5:47 pm

If you didn't use that pin drill bit to clean the idle passages , they aren't rebuilt.

The Mike Nixon book details the process step by step

https://www.motorcycleproject.com/text/booknook_2017_dohc_carb.html

The cutouts on the side of the carbs effect the idle and should be replaced if they have holes or are dried out. Old dried O rings and accelerator pump diaphragms s/b replaced too.

If you soaked your carbs with out removing the cutouts, the cutout diaphragms are probably ruined, and need replacement. If you sprayed carb cleaner into your jets from the float side without removing the cutouts, you probably ruined them.

You also need to clear the idle passage with a number#80 drill bit too. It's all in the book. If you search this site, all the info is available if you can pick out what you need.

You also need to do a compression check to verify the mechanical condition of the engine.

And these engines have shimmed valve adjustment , so the valve cover needs to come off and all valve clearances need to be checked and readjusted where necessary..Shoot for .005" on all valves

I went with the Randaak kit for my carbs.

http://www.randakks.com/DOHC%20Four%20Page.htm

Please don't butcher the bike to make one of those butchered, half ass cafe bikes....Putting a tank from a different bike painted with a spray can, and cutting off the fenders just means you are making a piece of shit that other motorcyclists laugh at when you lose interest and put it on craigslist....What's funny is that individuals list often list their bikes in "modified" form for $5000, and in reality, the POS they just created is worth $500 as parts.

Oh yeah, these bikes have CV carbs and don't work well without stock paper air filters and factory airboxes.

Using pod filters is a fast way to making a bike that runs worse than stock and gets 25 Mpg..even if you can eventually jet it to run with out bogging

Some guys (rarely) have made nice cafe bikes, but I suspect they spent a minimum of 5K in parts and paint.....most create the bikes that we laugh at

http://www.cb1100f.net/modules.php?name=Forums&file=viewtopic&t=88385

Good luck....

Posted: Tue Dec 10, 2019 6:48 pm

DBShiznit wrote:

Long story short, I wanted some guidance. Should I restore this bike, make it a cafe racer or just sell it to someone who knows what they're doing? I'm mechanically inclined and just have the bike sitting and would like to do something with it, just dont know what is worth doing with it. Let me know what you guys think!

You will likely get more money for it if you sell it as is. If you café it, (these bikes aren't good candidates for that type of debauchery) it will probably be worth less than what you paid for the bike, not to mention the extra money you put into it.

Look for a decent used tank - they're out there. Get it running properly, rebuild the brake system and address whatever else it needs to be mechanically sound. Then ride it. If you like the bike, you can put money into the cosmetics later. If you don't, it will probably sell for more than you have into it, since it will be road-worthy for the next owner.

MB-5 Joined: Mar 27, 2019 Posts: 4 Location: Philadelphia

tomk1960 wrote:

DBShiznit wrote:

Long story short, I wanted some guidance. Should I restore this bike, make it a cafe racer or just sell it to someone who knows what they're doing? I'm mechanically inclined and just have the bike sitting and would like to do something with it, just dont know what is worth doing with it. Let me know what you guys think!

You will likely get more money for it if you sell it as is. If you café it, (these bikes aren't good candidates for that type of debauchery) it will probably be worth less than what you paid for the bike, not to mention the extra money you put into it.

Look for a decent used tank - they're out there. Get it running properly, rebuild the brake system and address whatever else it needs to be mechanically sound. Then ride it. If you like the bike, you can put money into the cosmetics later. If you don't, it will probably sell for more than you have into it, since it will be road-worthy for the next owner.

Honestly I rode it, and it's a bit too high for me and I don't feel comfortable with it. (I'm 5'6) I used a bottle to feed gas into the carbs just to take it up and down the driveway to make sure everything still worked. Clutch brakes run it through gears etc. I know its a one off bike so I didnt just want to butcher it when someone else could have the chance to rebuild it or own something they always wanted.

The carbs were recently rebuilt before I bought the bike and I have all the parts including a new battery that probably needs to be charged. I also heard 15k miles is a lot of miles for the bike so thats another thing I'm not sure about.

MB-5 Joined: Mar 27, 2019 Posts: 4 Location: Philadelphia

f4fast wrote:

If you didn't use that pin drill bit to clean the idle passages , they aren't rebuilt.

The Mike Nixon book details the process step by step

https://www.motorcycleproject.com/text/booknook_2017_dohc_carb.html

The cutouts on the side of the carbs effect the idle and should be replaced if they have holes or are dried out. Old dried O rings and accelerator pump diaphragms s/b replaced too.

If you soaked your carbs with out removing the cutouts, the cutout diaphragms are probably ruined, and need replacement. If you sprayed carb cleaner into your jets from the float side without removing the cutouts, you probably ruined them.

You also need to clear the idle passage with a number#80 drill bit too. It's all in the book. If you search this site, all the info is available if you can pick out what you need.

You also need to do a compression check to verify the mechanical condition of the engine.

And these engines have shimmed valve adjustment , so the valve cover needs to come off and all valve clearances need to be checked and readjusted where necessary..Shoot for .005" on all valves

I went with the Randaak kit for my carbs.

http://www.randakks.com/DOHC%20Four%20Page.htm

Please don't butcher the bike to make one of those butchered, half ass cafe bikes....Putting a tank from a different bike painted with a spray can, and cutting off the fenders just means you are making a piece of shit that other motorcyclists laugh at when you lose interest and put it on craigslist....What's funny is that individuals list often list their bikes in "modified" form for $5000, and in reality, the POS they just created is worth $500 as parts.

Oh yeah, these bikes have CV carbs and don't work well without stock paper air filters and factory airboxes.

Using pod filters is a fast way to making a bike that runs worse than stock and gets 25 Mpg..even if you can eventually jet it to run with out bogging

Some guys (rarely) have made nice cafe bikes, but I suspect they spent a minimum of 5K in parts and paint.....most create the bikes that we laugh at

http://www.cb1100f.net/modules.php?name=Forums&file=viewtopic&t=88385

Good luck....

Thats definitely not what I had in mind. I work in a body shop. I'd have the tank acid dipped and have one of the techs plus all the wholes with a welder and get it painted correctly. If I was doing a cafe racer then I'd maybe paint it in a different color or scheme. As far as the carbs they were rebuilt at a shop. I can look into all the info you gave me and start from there.

As far as my questions I was looking for guidance with the bike. Cafe racer would be done correctly not me cutting corners. I come from an automotive background and have a high powered car that I perform all the work on and my daily driver, although nothing carburated. If I restore it it would also be a restore and not cutting corners again however I believe custom work would be easier to do since parts can be expensive to restore with. I could be wrong however. Or just give up on it and let someone else take on the challenge. I wouldn't be opposed to it. Just didnt want to give up on it easily.

Posted: Tue Dec 10, 2019 7:14 pm

DBShiznit wrote:

I also heard 15k miles is a lot of miles for the bike so thats another thing I'm not sure about.

15K is not a lot of miles for this bike, so that won't be true unless they were incredibly hard ridden miles, with no valve or tensioner adjustments made and infrequent oil changes. A quick compression test should give you a decent idea of how it is.

Posted: Tue Dec 10, 2019 7:24 pm

I can come up from Wilmington and relieve you of the burden of that bike if you want. Or I can help you fix it up, I've been around the block with these monsters and I'm only about 30 minutes away.

MB-5 Joined: Mar 27, 2019 Posts: 4 Location: Philadelphia

Tdem wrote:

I can come up from Wilmington and relieve you of the burden of that bike if you want. Or I can help you fix it up, I've been around the block with these monsters and I'm only about 30 minutes away.

I have to find the title. If you want you can come up and take a peak at it and see what you think? It would have to be the weekend of the 21 since I work this weekend or we can wait until after the holidays I'm honestly in no rush to sell. Just trying to get an idea on what to do with it for now but if you make me an offer I wont be rude and decline it. I just hope if I let it go I can get what I paid for it not counting money for oil change battery and what ever else I put into it. If I can't then I might just get to work on it over the winter and sell it as a running bike.