hot restart problem!

hello fellow viffers!
I have a problem with restarting my bike after it has been warmed up and driven for a while. I have to pump the throttle for a while and then hold it all the way open to get it restarted. When it finally restarts I dont get any black smoke out of the exhaust like it was flooded. Im thinking something is losing pressure somewhere? I ripped the carbs apart about a month ago and cleaned them and didnt notice any cracked diaphrams or anything that would explain this situation. Could it possibly be the fuel pump? I dont think its an R/R issue as I can always get is started but its kind of embarrassing to have to turn it over so long to get it to fire! Any suggestions on where to start looking?
Thanks,
Devonshire

 

Have you cleaned your inline fuel filter?

 

you mean the one right before the fuel pump? i cleaned it when i cleaned my carbs. also no rust in my tank. i will check it again.

 

rechecked my fuel filter and it appears clean to me. also all connections to fuel pump and r/r seem good and tight. i hope its not the r/r! i always thought that when they go they are either completely shot or you have to wait for them to cool down for 20 min. or so?

 

That's a common occurrence - not a problem. Just normal with carburetted bikes. From what I've read, the hot carbs cause the gas to evaporate and the fumes to hang about lazily in the airbox - causing a too rich mixture that won't allow the bike to start.

Twist the throttle WO and attempt to start the bike. This will clear out the fumes. Once the bike starts to catch, immediately bring the throttle back to normal.

It will never start hot like it does cold.

 

thanks mason. just started having this problem. it didnt do it for about the first three weeks ive had the bike. kind of embarassing when everyone else can just hop on their bikes and start them and go and they have to wait for my dinosaur to start! I guess thats part of owning an old bike! Would LOVE to upgrade to a newer vfr, but this 1984 is my first bike and I should prob just ride this one until next year. I absolutely love the bike, even if it is 23 years old!

 

I don't think it's normal. My 83 Interceptor starts right up, hot or cold. You might have a vapor lock problem. The gas in the lines and carbs gets hotter when you stop the bike because you no longer have fuel flowing and you no longer have air flow. My 82 Sabre (same engine) did this once and turned out to be (believe it or not) the starter. It would crank over fine, but it was dragging a little causing a huge drain on the battery, which left little elect. for the ignition. If you are a little handy with a wrench, take the starter apart, lightly sand the area where the brushes touch, install new brushes (make sure you get BOTH parts) my part #'s were 31201-KG7-000 and 31206-KG7-000. I know this is hard to believe, but I've seen this a couple of times. Anyway it wouldn't hurt to go through your starter, and only will cost about $40.00, and should correct your problem. My Sabre always started fine when cold, but acted up only when hot. Be sure to let me know if this works for you.

 

When was the last time the valves were adjusted? My 93 would do almost the same thing. I just didn't have to pump the throttle hard, maybe just a little twist. My valves, according to the mech, were way out. But I don't have the numbers.

 

Same thing is happening with my 1984 Interceptor. I can tell that the hot starter isn't cranking as quickly as it should. I was just about to check the brushes out. Thanks for the reminder.

 

Be sure to let me know if this works for you.

 

thanks everyone for your input! hard to believe that the starter might be the culprit! I bought the bike with 13,700 miles and now have 14,300. I dont know when the valves were adjusted last if ever but it is on my list of things to do! I might try to tackle the starter issue first as it seems a little easier project! When is honda's scheduled valve adjustment? 10,000? 15,000? Seems like a hefty project but I should probably check them though as the bike sat in previous owners garage without being started for 4 years!

 

I believe Honda first said 16,000 - but then changed it to 8,000 miles.

Sabre Starter Rebuild: http://www.netcrafting.com/motorcycles/sabre/starter_rebuild.htm

Note: Ceptor starters turn opposite of Sabres.

 

Just as an FYI, pumping the throttle won't do anything, we don't have accelerator pumps.

 

The valve adjustment is criticle on these bikes. Honda had a problem on the top end. They don't get much oil in the top end, especially at idle. Also the cams are a little soft and tend to wear out at about 25,000 miles. You should have the valves checked as soon as you can. If they get tight, the rockers will wear grooves in the cams. Also if you idle for long periods the cams will wear at the journals. If you plan to keep this bike, you might look at an oil mod kit. It will pump extra oil to the top end, slowing down the wear. If you do the valve job yourself, be sure to buy the book, and follow it exactly. You have to use 2 feeler gages at the same time to get a proper adjustment. The Clymer book walks you through it step by step. I still feel sure the starter rebuild will fix your hot starting issues.

 

eddy, love your '07 Interceptor. My bike has a similar paint scheme, although mine is a hybrid '84-'85.

THREAD HIJACK!

The oil mod - which one is best? My bike already has 29,000 miles on it, although many of those are recent with Aimsoil 10-40 and at relatively high RPM (no lugging, for sure, because I went down a tooth in front). I wonder if I should do the mod now, or what?

 

The oil mod kit is a little pricey, but if you plan to keep the bike I would consider it. The best ones don't require any drilling, and use an adapter on the oil filter, then routes the oil to the top end. You'd have to do long term tests and ruin 3 or 4 good bikes to know it the thing even helps. I can't think of anyone willing to do that. I know a couple of people who say they like them, but I don't know how they know if they even work.