Is this manifold a disgrace?

D

Dave Strome

New Member
I picked up a cheap 26" mountain bike to install a kit on. It is one of the $100 el-cheapo bikes from a big box store. In the end, I'm glad I used an inexpensive bike for my first one, and this one really works great - except that it is a VERY tight fit and I had to extend the intake manifold quite a bit. Since I really don't have any skills to build something better, I cut the pipe and used some marine-grade fuel line to extend it. Everything is tight. Is there any reason why the intake should be metal? Will I see any problems later on? Is an intake this long limiting power? The bike runs great! I only have a few miles on it, just finished the build and started taking it out. Only so much riding you can do below 20 degrees on icy streets! :-) Any feedback is appreciated! - Dave
 

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You say it runs great? Good! I think you answered your own question. I don't see any problems with it. I would however, keep an eye on the rubber nearest the motor. If heat from the motor degrades the rubber over time it could cause problems.

Welcome to the forum!
 
As long as the carburetor is level, doesn't vibrate too much and is secure you're probably good to go. Several other members have had decent luck with flexible material for an intake. Is the hose fuel grade? That is, is it made to carry gasoline? If not then I'd replace it with something that is but if it is fuel line it should provide you with reasonable service. If possible could you post a picture of the entire bike? Is it a 26" bike or a 24". It is odd and unusual that things fit that tight.
Tom
 
Ok! Just what I was hoping to hear! The carb is pretty level and secure, no problems there. It is a marine fuel line, so yes, made to carry fuel. As I said, the connections are tight with the clamps, but will take the advice to watch the motor side to see if it becomes a problem due to the heat.

Picture of the bike is attached. I couldn't find a better way to mount the motor. The pic is from before the bike was finished, but shows the size and placement of the motor.

This is an excellent site and fantastic online community! Hats off to all involved...

Thanks! - Dave
 

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manifold is more than one opening-those are ports-single opening-single cylinder is ports-multi cylinder is manifold- its just teminology anyway- glad to here your bike is working good-I'm gona be out of it for a while:):)
 
man , your motor is right against the top bar , is it a mountain bike or a BMX ? tight fit , good job . lets se the whole bike
 
Hello , It looks like the clutch cable may be rubbing the bottom of your hose. It could rub thru and if so will start to run lean.. I'd check that and if OK go for it ....T
 
Looks good Dave. Really great workaround. That will help lots of folks with tight fits. Good job.
 
Dave, no leaks it's all good. Yes honey I will put the lasagne in as soon as I find my 10mm wrench. Did you put it in the silverware drawer or the junk drawer? Nothing like a motoredbike to add to the kitchen ambiance, love it.
 
Good job dave and thats a nice build, if that intake gives you any problems some of the sponsors to this forum sell offset intake manifolds that are solid much like the original intake, Good luck and welcome to the forumn!!!
 
RusticoRay said:
Dave, no leaks it's all good. Yes honey I will put the lasagne in as soon as I find my 10mm wrench. Did you put it in the silverware drawer or the junk drawer? Nothing like a motoredbike to add to the kitchen ambiance, love it.
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Now THAT is funny! I showed this comment to my wife.. and yes, for anyone wondering, I built the whole bike in my kitchen! Not a lot of options for me this time of year!

Thanks for all the great input guys.. really appreciate it!

It really worked out well - the hose has a slight curve to it, which put the carb exactly where I wanted it.

Thanks again! Will post another picture of the finished bike. It's got a basket, a bell that rings, and things to make it look good. I'm very pleased with the way it turned out, especially after hearing some positive feedback from you folks about my one concern.

Dave
 
Dave, just noticed your from Maine. Have get togethers starting in the early spring and a few informal ones yr round. They are a blast. I host one in CT (just a cook out and a group ride) But there were a couple in Mass last yr too. Be sure to check out the events section.
 
Dave,
Now that I see the bike I can understand your clearance problem but it prompts me to ask why you mounted the motor so high in the frame. If it were lower you wouldn't need the angled intake. I see maybe you have extended the front mount to facilitate the higher engine mounting. Could you mount it lower in the 'V'? Is it a 24" bike?
Tom
 
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It is a 26" - just a really small frame. I tried moving the motor around as much as possible, but that's the best I could come up with. I really couldn't get it any lower. Maybe if I try again, I may be able to adjust it a bit.. but I don't think I'll be able to gain very much. I spent quite a bit of time experimenting with the placement. You're right though, if I revisit the front mount, I may be able to save an inch, but I don't think that will be enough for the carb to clear.
 
Here's a pic of the completed bike.. very, very pleased with it. Thanks again for all your input! - Dave
 

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Dave,
Looks like you're ready to join the ranks of the motorized crowd. Enjoy it, have fun and ride safe. We're always here if you need future help. Good job and congratulations.
Tom
 
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